Tony Pearson is a Master Inventor and Senior IT Architect for the IBM Storage product line at the
IBM Executive Briefing Center in Tucson Arizona, and featured contributor
to IBM's developerWorks. In 2016, Tony celebrates his 30th year anniversary with IBM Storage. He is
author of the Inside System Storage series of books. This blog is for the open exchange of ideas relating to storage and storage networking hardware, software and services.
(Short URL for this blog: ibm.co/Pearson )
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Continuing my catch-up on past posts, Jon Toigo on his DrunkenData blog, posted a ["bleg"] for information aboutdeduplication. The responses come from the "who's who" of the storage industry, so I will provide IBM'sview. (Jon, as always, you have my permission to post this on your blog!)
Please provide the name of your company and the de-dupe product(s) you sell. Please summarize what you think are the key values and differentiators of your wares.
IBM offers two different forms of deduplication. The first is IBM System Storage N series disk system with Advanced Single Instance Storage (A-SIS), and the second is IBM Diligent ProtecTier software. Larry Freeman from NetApp already explains A-SIS in the [comments on Jon's post], so I will focus on the Diligent offering in this post. The key differentiators for Diligent are:
Data agnostic. Diligent does not require content-awareness, format-awareness nor identification of backup software used to send the data. No special client or agent software is required on servers sending data to an IBM Diligent deployment.
Inline processing. Diligent does not require temporarily storing data on back-end disk to post-process later.
Scalability. Up to 1PB of back-end disk managed with an in-memory dictionary.
Data Integrity. All data is diff-compared for full 100 percent integrity. No data is accidentally discarded based on assumptions about the rarity of hash collisions.
InfoPro has said that de-dupe is the number one technology that companies are seeking today — well ahead of even server or storage virtualization. Is there any appeal beyond squeezing more undifferentiated data into the storage junk drawer?
Diligent is focused on backup workloads, which has the best opportunity for deduplication benefits. The two main benefits are:
Keeping more backup data available online for fast recovery.
Mirroring the backup data to another remote location for added protection. With inline processing, only the deduplicated data is sent to the back-end disk, and this greatly reduces the amount of data sent over the wire to the remote location.
Every vendor seems to have its own secret sauce de-dupe algorithm and implementation. One, Diligent Technologies (just acquired by IBM), claims that their’s is best because it collapses two functions — de-dupe then ingest — into one inline function, achieving great throughput in the process. What should be the gating factors in selecting the right de-dupe technology?
As with any storage offering, the three gating factors are typically:
Will this meet my current business requirements?
Will this meet my future requirements for the next 3-5 years that I plan to use this solution?
What is the Total Cost of Ownership (TCO) for the next 3-5 years?
Assuming you already have backup software operational in your existing environment, it is possible to determine thenecessary ingest rate. How many "Terabytes per Hour" (TB/h) must be received, processed and stored from the backup software during the backup window. IBM intends to document its performance test results of specific software/hardwarecombinations to provide guidance to clients' purchase and planning decisions.
For post-process deployments, such as the IBM N series A-SIS feature, the "ingest rate" during the backup only has to receive and store the data, and the rest of the 24-hour period can be spent doing the post-processing to find duplicates. This might be fine now, but as your data grows, you might find your backup window growing, and that leaves less time for post-processing to catch up. IBM Diligent does the processing inline, so is unaffected by an expansion of the backup window.
IBM Diligent can scale up to 1PB of back-end data, and the ingest rate does not suffer as more data is managed.
As for TCO, post-process solutions must have additional back-end storage to temporarily hold the data until the duplicates can be found. With IBM Diligent's inline methodology, only deduplicated data is stored, so less disk space is required for the same workloads.
Despite the nuances, it seems that all block level de-dupe technology does the same thing: removes bit string patterns and substitutes a stub. Is this technically accurate or does your product do things differently?
IBM Diligent emulates a tape library, so the incoming data appears as files to be written sequentially to tape. A file is a string of bytes. Unlike block-level algorithms that divide files up into fixed chunks, IBM Diligent performs diff-compares of incoming data with existing data, and identifies ranges of bytes that duplicate what already is stored on the back-end disk. The file is then a sequence of "extents" representing either unique data or existing data. The file is represented as a sequence of pointers to these extents. An extent can vary from2KB to 16MB in size.
De-dupe is changing data. To return data to its original state (pre-de-dupe) seems to require access to the original algorithm plus stubs/pointers to bit patterns that have been removed to deflate data. If I am correct in this assumption, please explain how data recovery is accomplished if there is a disaster. Do I need to backup your wares and store them off site, or do I need another copy of your appliance or software at a recovery center?
For IBM Diligent, all of the data needed to reconstitute the data is stored on back-end disks. Assuming that all of your back-end disks are available after the disaster, either the original or mirrored copy, then you only need the IBM Diligent software to make sense of the bytes written to reconstitute the data. If the data was written by backup software, you would also need compatible backup software to recover the original data.
De-dupe changes data. Is there any possibility that this will get me into trouble with the regulators or legal eagles when I respond to a subpoena or discovery request? Does de-dupe conflict with the non-repudiation requirements of certain laws?
I am not a lawyer, and certainly there are aspects of[non-repudiation] that may or may not apply to specific cases.
What I can say is that storage is expected to return back a "bit-perfect" copy of the data that was written. Thereare laws against changing the format. For example, an original document was in Microsoft Word format, but is converted and saved instead as an Adobe PDF file. In many conversions, it would be difficult to recreate the bit-perfect copy. Certainly, it would be difficult to recreate the bit-perfect MS Word format from a PDF file. Laws in France and Germany specifically require that the original bit-perfect format be kept.
Based on that, IBM Diligent is able to return a bit-perfect copy of what was written, same as if it were written to regular disk or tape storage, because all data is diff-compared byte-for-byte with existing data.
In contrast, other solutions based on hash codes have collisions that result in presenting a completely different set of data on retrieval. If the data you are trying to store happens to have the same hash code calculation as completely different data already stored on a solution, then it might just discard the new data as "duplicate". The chance for collisions might be rare, but could be enough to put doubt in the minds of a jury. For this reason, IBM N series A-SIS, that does perform hash code calculations, will do a full byte-for-byte comparison of data to ensure that data is indeed a duplicate of an existing block stored.
Some say that de-dupe obviates the need for encryption. What do you think?
I disagree. I've been to enough [Black Hat] conferences to know that it would be possible to read thedata off the back-end disk, using a variety of forensic tools, and piece together strings of personal information,such as names, social security numbers, or bank account codes.
Currently, IBM provides encryption on real tape (both TS1120 and LTO-4 generation drives), and is working withopen industry standards bodies and disk drive module suppliers to bring similar technology to disk-based storage systems.Until then, clients concerned about encryption should consider OS-based or application-based encryption from thebackup software. IBM Tivoli Storage Manager (TSM), for example, can encrypt the data before sending it to the IBMDiligent offering, but this might reduce the number of duplicates found if different encryption keys are used.
Some say that de-duped data is inappropriate for tape backup, that data should be re-inflated prior to write to tape. Yet, one vendor is planning to enable an “NDMP-like” tape backup around his de-dupe system at the request of his customers. Is this smart?
Re-constituting the data back to the original format on tape allows the original backup software to interpret the tape data directly to recover individual files. For example, IBM TSM software can write its primary backup copies to an IBM Diligent offering onsite, and have a "copy pool" on physical tape stored at a remote location. The physical tapes can be used for recovery without any IBM Diligent software in the event of a disaster. If the IBM Diligent back-end disk images are lost, corrupted, or destroyed, IBM TSM software can point to the "copy pool" and be fully operational. Individual files or servers could be restored from just a few of these tapes.
An NDMP-like tape backup of a deduplicated back-end disk would require that all the tapes are in-tact, available, and fully restored to new back-end disk before the deduplication software could do anything. If a single cartridge fromthis set was unreadable or misplaced, it might impact the access to many TBs of data, or render the entire systemunusable.
In the case of a 1PB of back-end disk for IBM Diligent, you would be having to recover over a thousand tapes back to disk before you could recover any individual data from your backup software. Even with dozens of tape drives in parallel, could take you several days for the complete process.This represents a longer "Recovery Time Objective" (RTO) than most people are willing to accept.
Some vendors are claiming de-dupe is “green” — do you see it as such?
Certainly, "deduplicated disk" is greener than "non-deduplicated" disk, but I have argued in past posts, supportedby Analyst reports, that it is not as green as storing the same data on "non-deduplicated" physical tape.
De-dupe and VTL seem to be joined at the hip in a lot of vendor discussions: Use de-dupe to store a lot of archival data on line in less space for fast retrieval in the event of the accidental loss of files or data sets on primary storage. Are there other applications for de-duplication besides compressing data in a nearline storage repository?
Deduplication can be applied to primary data, as in the case of the IBM System Storage N series A-SIS. As Larrysuggests, MS Exchange and SharePoint could be good use cases that represent the possible savings for squeezing outduplicates. On the mainframe, many master-in/master-out tape applications could also benefit from deduplication.
I do not believe that deduplication products will run efficiently with “update in place” applications, that is high levels of random writes for non-appending updates. OLTP and Database workloads would not benefit from deduplication.
Just suggested by a reader: What do you see as the advantages/disadvantages of software based deduplication vs. hardware (chip-based) deduplication? Will this be a differentiating feature in the future… especially now that Hifn is pushing their Compression/DeDupe card to OEMs?
In general, new technologies are introduced on software first, and then as implementations mature, get hardware-based to improve performance. The same was true for RAID, compression, encryption, etc. The Hifn card does "hash code" calculations that do not benefit the current IBM Diligent implementation. Currently, IBM Diligent performsLZH compression through software, but certainly IBM could provide hardware-based compression with an integrated hardware/software offering in the future. Since IBM Diligent's inline process is so efficient, the bottleneck in performance is often the speed of the back-end disk. IBM Diligent can get improved "ingest rate" using FC instead of SATA disk.
Sorry, Jon, that it took so long to get back to you on this, but since IBM had just acquired Diligent when you posted, it took me a while to investigate and research all the answers.
In this case, it is not chess pieces, but FUD being slung around like mud between vendors. EMC blogger Chuck Hollis' post [Products vs. Features] correctly pointsout that IBM has invented most nearly everything useful in IT, and sadly a few things we wish we hadn't.Gene Amdahl, who left IBM to start his own company, is credited for coining the phrase describing IBM'sinnovative sales techniques. Wikipedia has a nice write up on the history of[Fear, Uncertainty and Doubt(FUD)].
Nowadays, when you hear "FUD" most storage administrators immediately think of EMC, who have taken this method to anew level of art-form. Take for example two EMC entries from fellow blogger BarryB, on his Storage Anarchist blog:[Not Dead Yet, andPushing Daisies].The first is a reference to a funny scene from a Monty Python movie, and the second one is referring to a terriblenew television program called "Pushing Daisies". (In this show, the main character can bring a dead personback to life for sixty seconds, just long enough to ask a few questions on behalf of his detective friend. He must touch the person again within 60 seconds, or someone else randomly dies instead. I amnot a fan of this concept, and found it a bit morbid and creepy. But I digress.)
It is true I was on vacation the past two weeks, but this was group travel I booked over six months ago before we had the exact dates lined up for our various announcements, and not a last-minute celebration of my recent new job assignment. I got all my assignments for this announcement turned in before leaving for my trip. I never thought of checking with fellow IBM blogger BarryW to make sure that we don't have overlapping vacation schedules, leaving the "blogosphere" unmanned, so to speak, but it is not a bad idea. Fortunately, our IBM PR team was able to make their rebuttal through other means. You can read the recap on Techworld [Marketing Wars by Proxy].
Several astute readers on my blog, however, requested that I add my two cents. Let's take a look at some of BarryB's comments:
...most DS8300's are to this day most frequently bundled as "free" storage with IBM mainframe and server sales.
We just shipped our 15,000th box, so for this absurd statement to be true, more than half would have to be given away as part of a server-and-storage deal?Actually, about a third of our DS8000 sales are sold with servers in the same bundle, and while we do provide discounts from the official list price, that is not the same as "free". The other two thirds are sold into accounts to be used with the existing servers already deployed. So BarryB, your math doesn't work out. (Perhaps you've been taking Hitachi math lessons???)
It is interesting however, that when we do a 4-year TCO comparison, between a normally-discounted DS8000 versus free EMC DMX4 hardware, IBM still has the lower cost, given that most of the price-gouging from EMC happens after the initial sale, through software features, annual Powerpath renewals and MES upgrades. If you are an EMC customer, and you are planning to add more capacity to your DMX, ask EMC to charge you no more than what you originally paid on a dollar-per-GB basis for the initial capacity. That's only fair, right?
...No thin provisioning, or even a commitment to thin provisioning. Just crickets. (Celerra support since Jan 2006...
EMC DMX does not have thin provisioning available today either, so BarryB brings up Celerra, their NAS box? IBM System Storage N series NAS box also has thin provisioning, so if you want thin provisioning you can buy a NAS box from EMC or IBM. Thin provisioning makes sense using NAS protocols, as there are actual commands to "delete a file" that can then free up the related blocks in a thin-provisioned environment. The only way to do this with block-oriented protocols is to get the OS to notify the storage device that blocks can be freed up. As it turns out, IBM's z/OS has such support, which we developed specifically for our thin-provisioning support in our IBM RAMAC Virtual Array disk systems back in the 1990s.For block-oriented devices on most other operating systems, thin provisioning may not be all that it is cracked up to be.
No SATA drives (only DMX-4 supports native SATA-II drives, since Aug’07)
A few people are confused on this. IBM DS8000 has supported FATA for quite some time now, same slower speeds and higher capacities as SATA, but are technically NOT the same as SATA. FATA are designed to provide better protection against vibrational shock, to improve reliability of the drives. IBM felt that if the data was important enough to put on a high-end system, it should get better-than-SATA treatment. If you really want SATA, try our IBM System Storage N series, DS4000 or DS3000 models.
No RAID 6 (DMX-3 has supported multi-dimensional RAID since Q1’07, DMX-4 since Aug'07, ...
IBM N series supports RAID6, but we called it RAID-DP and that confused some people. Same thing, DP stands for Dual Parity, protecting against a double-disk failure. We also just announced RAID6 on our DS4000 series, by the way.
No 4Gb back-end (USP-V since May '07, DMX-4 since Aug’07)
I found this one odd, since BarryB himself in an earlier post explained why 4Gbps back-end made no difference to DMX4 performance in this post [DMX-4 and Oh So Much More], which I will put into a different color so you can tell it is from a different post:
You may have noticed that there weren't any specific performance claims attributed to the new 4Gb FC back-end. This wasn't an oversight, it is in fact intentional. The reality is that when it comes to massive-cache storage architectures, there really isn't that much of a difference between 2Gb/s transfer speeds and 4Gb/s. Transmit times are really only a tiny portion of I/O overhead, and just don't make that much difference when a massively-cached system is pre-fetching reads, buffering/delaying writes and reordering I/O requests to minimize seek times. Not that 4Gb/s won't help some applications, but most people just won't see any noticeable difference.
In this case, BarryB is right. The IBM DS8000's 2Gbps back-end is not a performance bottleneck. The DS8000 with a 2Gbps back-end is faster than DMX4 with a 4Gbps back-end for business application workloads. EMC doesn't publish SPC benchmarks to deny this, so you will just have to take our word on this.
Still only 1024 maximum disk drives (DMX-3 & 4 support up to 2400 drives, USP-V supports 1152)
I would be curious to see how many customers have more than 1024 drives on any high-end disk array.As we learned back in [Day 2 Storage Symposium], the average DS8100 has 17.4 TB, and DS8300 has 41.5 TB capacity. Using 500GB drives,that's only 83 spindles. Even with 73GB drives, that's 568 spindles. Plenty of room for growth, so I am notconvinced that higher theoretical upper architectural limits are worth discussing here.
Still only two HARD LPARs (partitions) ..., and even IBM’s mid-tier products support more than 2 storage partitions (in this same announcement)
IBM's two LPARs are TWICE what EMC DMX offers. I don't even know why anyone from EMC would bring this up? While EMC is enjoying their success with VMware, the lack the experience to carry this over to their storage lines. Until EMC offers MORE THAN TWO of any kind of partitions on their high-end offerings, there just is no credibility here. As for our "storage partitions" on our DS4000 line, that is an unfortunate mis-understanding of the press release. On the DS4000, the term "storage partition" is really "LUN masking", dividing up only which disks can be accessed by which hosts, and not dividing up any processor or cache capacity. So this is not the same as any LPAR concept on any other system. For example, a DS4000 with 64 partitions can be attached to 64 hosts, or 64 host-clusters like a Windows MSCS environment or AIX HACMP.
No native Ethernet replication or iSCSI support (Symmetrix has had since 2002)
Again, I found this one odd. On another EMC post, [Vigorous Debates],Chad Sakac mentions that only 2% of Symmetrix are sold with IP ports, not sure if this is for Ethernet replication, iSCSI attachment, or both (Again, I will use a different color):
On the Symm business (a huge part of EMC’s business – the IP ports are included on 2% of deals. That’s a fact.
Just because engineer can put a feature or function on a box, doesn't mean there is business sense to do so. I would hate for IBM to invest millions of dollars on native iSCSI support, only to have 2% of our DS8000 boxes sold with that feature. Customers who have DS8000 on FC SANs already deployed can easily add iSCSI support either through their SAN switches, or by fronting the DS8000 with an N series gateway. Most customers looking for native iSCSI are the smaller no-SAN-deployed SMB customers, and for them, we have both the DS3300 and the various N series models to choose from.
Well that's my two cents. The DS8000 series remains a strategic part of the IBM System Storage offering matrix, with continued investment in the development, as well as on-going research that we can leverage throughout the IBM company. I would like to read your thoughts on this, post me a comment below.
Continuing my week in Washington DC for the annual [2010 System Storage Technical University], I presented a session on Storage for the Green Data Center, and attended a System x session on Greening the Data Center. Since they were related, I thought I would cover both in this post.
Storage for the Green Data Center
I presented this topic in four general categories:
Drivers and Metrics - I explained the three key drivers for consuming less energy, and the two key metrics: Power Usage Effectiveness (PUE) and Data Center Infrastructure Efficiency (DCiE).
Storage Technologies - I compared the four key storage media types: Solid State Drives (SSD), high-speed (15K RPM) FC and SAS hard disk, slower (7200 RPM) SATA disk, and tape. I had comparison slides that showed how IBM disk was more energy efficient than competition, for example DS8700 consumes less energy than EMC Symmetrix when compared with the exact same number and type of physical drives. Likewise, IBM LTO-5 and TS1130 tape drives consume less energy than comparable HP or Oracle/Sun tape drives.
Integrated Systems - IBM combines multiple storage tiers in a set of integrated systems managed by smart software. For example, the IBM DS8700 offers [Easy Tier] to offer smart data placement and movement across Solid-State drives and spinning disk. I also covered several blended disk-and-tape solutions, such as the Information Archive and SONAS.
Actions and Next Steps - I wrapped up the talk with actions that data center managers can take to help them be more energy efficient, from deploying the IBM Rear Door Heat Exchanger, or improving the management of their data.
Greening of the Data Center
Janet Beaver, IBM Senior Manager of Americas Group facilities for Infrastructure and Facilities, presented on IBM's success in becoming more energy efficient. The price of electricity has gone up 10 percent per year, and in some locations, 30 percent. For every 1 Watt used by IT equipment, there are an additional 27 Watts for power, cooling and other uses to keep the IT equipment comfortable. At IBM, data centers represent only 6 percent of total floor space, but 45 percent of all energy consumption. Janet covered two specific data centers, Boulder and Raleigh.
At Boulder, IBM keeps 48 hours reserve of gasoline (to generate electricity in case of outage from the power company) and 48 hours of chilled water. Many power outages are less than 10 minutes, which can easily be handled by the UPS systems. At least 25 percent of the Computer Room Air Conditioners (CRAC) are also on UPS as well, so that there is some cooling during those minutes, within the ASHRAE guidelines of 72-80 degrees Fahrenheit. Since gasoline gets stale, IBM runs the generators once a month, which serves as a monthly test of the system, and clears out the lines to make room for fresh fuel.
The IBM Boulder data center is the largest in the company: 300,000 square feet (the equivalent of five football fields)! Because of its location in Colorado, IBM enjoys "free cooling" using outside air temperature 63 percent of the year, resulting in a PUE of 1.3 rating. Electricity is only 4.5 US cents per kWh. The center also uses 1 Million KwH per year of wind energy.
The Raleigh data center is only 100,000 Square feet, with a PUE 1.4 rating. The Raleigh area enjoys 44 percent "free cooling" and electricity costs at 5.7 US cents per kWh. The Leadership in Energy and Environmental Design [LEED] has been updated to certify data centers. The IBM Boulder data center has achieved LEED Silver certification, and IBM Raleigh data center has LEED Gold certification.
Free cooling, electricity costs, and disaster susceptibility are just three of the 25 criteria IBM uses to locate its data centers. In addition to the 7 data centers it manages for its own operations, and 5 data centers for web hosting, IBM manages over 400 data centers of other clients.
It seems that Green IT initiatives are more important to the storage-oriented attendees than the x86-oriented folks. I suspect that is because many System x servers are deployed in small and medium businesses that do not have data centers, per se.
You may not be the right person to ask but I am asking everyone so "How do you see hybrid disk drives?"
(For the record, I am not immediately related to Robert. At onepoint, "Pearson" was the 12th most common surname in the USA, but now doesn't even make the Top 100.)
Robert, I would like to encourage you and everyone else to ask questions, don't worry if I am the wrong person to ask, asprobably I know the right person within IBM. Some people have called me the "Kevin Bacon" of Storage,as I am often less than six degrees away from the right person, having worked in IBM Storage for over 20 years.
For those not familiar with hybrid drives, there is a good write-up in Wikipedia.
Unfortunately, most of the people I would consult on this question, such as those from Market Intelligence or Research, are on vacation for the holidays, so, Robert, I will have to rely on my trusted 78-card Tarot deck and answer you with a five-card throw.
Your first card, Robert, is the Hermit. This card represents "introspection". The best I/O is no I/O, which means that if applications can keep the information they need inside server memory, you can avoid the bus bandwidth limitations to going to external storage devices. Where external storage makes sense is when data is shared between servers, or when the single server is limited to a set amount of internal memory. So, consider maxing out the memory in your server first (IBM would be glad to sell you more internal memory!!!), then consider outside solid-state or hybrid devices. Windows for example has an architectural limit of 4GB.
Your second card, Robert, is the Four of Cups, representing "apathy".On the card, you see three cups together, with the fourth cup being delivered from a cloud. This reminds me thatwe have three storage tiers already (memory,disk,tape), and introducing a fourth tier into the mix may not garnermuch excitement. For the mainframe, IBM introduced a Solid-State Device, call the Coupling Facility, which can be accessed from multipleSystem z servers. It is used heavily by DFSMS and DB2 to hold shared information. However, given some customer's apathytowards Information Lifecycle Management which includes "tiered storage", introducing yet another tier that forcespeople to decide what data goes where may be another challenge.
Your third card, Robert, is the Chariot, which represents "Speed, Determination,and Will". In some cases, solid state disk are faster for reading, but can be slower for writing. In the case of ahybrid drive, where the memory acts as a front-end cache, read-hits would be faster, but read-misses might be slower.While the idea of stopping the drives during inactivity will reduce power consumption, spinning up and slowing downthe disk may incur additional performance penalties. At the time of this post, the fastest disk system remains the IBM SAN Volume Controller, based on SPC-1 and SPC-2 benchmarks in excess of those published for other devices.
Your fourth card, Robert, is the Eight of Pentacles, which represents"Diligence, Hard work". The pentacles are coins with five-sided stars on them, and this often represents money.Our research team has projected that spinning disk will continue to be a viable and profitable storage media for at least anothereight years.
Your fifth and last card, Robert, is the World, which normallyrepresents "Accomplishment", but since it is turned upside down, the meaning is reversed to "Limitation". Some Hybriddisks, and some types of solid state memory in general, do have limitations in the number of write cycles they can handle. For thoseunhappy with the frequency and slowness for rebuilds on SATA disk may find similar problems with hybrid drives.For that reason, businesses may not trust using hybrid drives for their busiest, mission-critical applications, but certainlymight use it for archive data with lower write-cycle requirements.
The tarot cards are never wrong, but certainly interpretations of the cards can be.
EMC Corporation (NYSE:EMC) today announced it has been positioned as a leader in the Forrester Wave™: Enterprise Open Systems Virtual Tape Library (VTL), Q1 2008 by Forrester Research, Inc. (January 31, 2008), an independent market and technology research firm. EMC achieved a position as a leader in the Forrester Wave report on virtual tape libraries based on the largest installed base of the EMC® Disk Library family of systems, its broad ecosystem interoperability. Virtual tape libraries emulate tape drives and work in conjunction with existing backup software applications, enabling fast backup and restoration of data by using high-capacity, low-cost disk drives.
EMC was the first major vendor in the open systems virtual tape library market as it introduced the EMC Disk Library in April 2004 and today is a leading provider of open systems virtual tape solutions, with systems that are designed for businesses and organizations of all sizes.
While the press release implies that "EDL equals VTL", Chuck tries to explain they are in fact very different. Here is an excerpt from his blog post:
Virtual Tape Libraries vs. Disk Libraries
As many of you know, VTLs have been around for a while. They use disk as a cache -- they buffer the incoming backup streams, do some housekeeping and stacking, then turn around and write tape efficiently. When you go to restore, you're usually coming back off of tape, unless the backup image in question is sitting in the disk cache.
Now, there is nothing wrong with the VTL approach, but it was conceived in a time when disks were horribly expensive. It was also pretty clear to many of us that disks were going to be a whole lot cheaper in the near future, and this fundamental assumption wouldn't be valid for much longer.
I kept thinking in terms of disk as a direct target for a backup application. No modifications to the backup application. Native speed of sequential disks for both backup and restore. Tape positioned as a backup to the backup. Use the strengths of the underlying array (e.g. CLARiiON) for performance, availability, management, etc.
We ended up calling the concept a "disk library" to differentiate from the VTLs that had come before it. It was a different value proposition and offering, based on the emergence of lower-cost disk media.
... It's nice to see we're at 1,100+ customers, and still going strong.
For those new to the blogosphere, there is a difference between "Press Releases" as formalcorporate communications versus "Blog Posts" which are informal opinions of the individual blogger, whichmay or may not match exactly the views of their respective employer.As we've learned many times before, one should not treat termslike "first" or "leader" in corporate press releases literally! Let's explore each.
Was EDL the first "open systems" Virtual Tape Library?
This is implied by the Forrester report. Chuck mentions the "VTLs that had came before it" in his blog, and many people are aware that IBM and StorageTek had introduced mainframe-attached VTLs in the 1990s. But what about VTL for "open systems"?
(Hold aside for the moment that IBM System zmainframe is an open system itself, with z/OS certified as a bona fide UNIX operating system by the [the Open Group] standards body. Most analysts and research firms usually refer only to the non-mainframe versions of UNIX and Windows. Alternative definitions for "open systems" can be foundin [Web definitions or Wikipedia]. I will assume Forrester meantnon-mainframe servers.)
IBM announced AIX non-mainframe attachment via SCSI connectivity to the IBM 3494 Virtual Tape Server (VTS) on Feb 16, 1999, with general availability in May 28, 1999. That's nearly FIVE YEARS before the April 2004 introduction of EDL. IBM VTS support for Sun Solaris and Microsoft Windows came shortly thereafter in November 2000, and support for HP-UX a bit later in June 2001. One of my 17 patents is for the software inside the IBM 3494 VTS, so like Chuck, I can takesome pride in the success of a successful product.
(I don't remember if StorageTek, which was subsequently acquired by Sun, had ever supported non-mainframe operating systems with their Virtual Storage Manager[VSM] offering, but if they did, I am sure it was also before EMC.)
Last week, another EMC blogger, BarryB (aka [the Storage Anarchist]),took me to task in comments on my post [IBM now supports 1TB SATA drives]. He felt that IBM should not claim support, given that the software inside the IBM System Storage N series is developed by NetApp. He compared this to the situation of HP and Sun re-badging the HDS USP-V disk system. If someone else wrote the software, BarryB opines, IBM should not claim credit for it. I tried to explain how IBM provides added value and has full-time employees dedicated to N series development and support, butdoubt I have changed his mind.
Why do I bring that up? Because the EMC Disk Library runs OEM software from FalconStor. Basically EMC is assembling a hardware/software solution with components provided from OEM suppliers. Hmmm? Sound familiar? Who is calling the kettle black?
If there is a clear winner here, it is FalconStor itself.Perhaps one of the worst kept industry secrets is that FalconStor software is also used in VTL offerings from Sun, Copan, and IBM, the latter embodied as the [IBM TS7520 Virtualization Engine] offering. If you like the concept of an EDL,but prefer instead one-stop shopping from an "information infrastructure" vendor, IBM can offer the TS7520 along with servers, software and services for a complete end-to-end solution.
Can EMC claim to be "a leader" in Virtual Tape Libraries?
During the measured quarter, IBM shipped its 10 millionth LTO-4 tape drive cartridge to Getty Images, the world's leading creator and distributor of still imagery, footage and multi-media products, as well as a recognized provider of other forms of premium digital content, including music. Getty Images is using the LTO-4 drives as part of a tiered infrastructure of IBM disk and tape solutions that help support the backup needs of their digital imagery;
IBM shipped more than 1,500 Petabytes of tape storage in Q3'07 alone;
During Q3'07, IBM shipped the 10,000th IBM System Storage TS3500 Tape Library. The TS3500 is a highly scalable tape library with support from 1 to 192 tape drives and up to 6,400 cartridge slots for open system, mainframe and virtual tape system attachment.
Let's take a look at the numbers. IBM has sold over 5,400 virtual tape libraries. Sun/STK has sold over 4,000 virtual tape libraries. Both are drastically more than the 1,100 mentioned in Chuck's post. Does IDC recognize EMC in third place? No, EMC chooses instead to declare EDL as disk arrays (probably toprop up their IDC "Disk Tracker" numbers), so they don't even earn an honorable mention under the virtual tape librarycategory. This of course includes the number of mainframe-attached models from IBM and Sun/STK. So, if EMC did call these tape systems instead, they might showup in third place, and as such EMC could claim to be "a leader" in much the same way an athlete can claim to be an "Olympic medalist" winning the bronze for third place. (If you limit thecount to just the FalconStor-based models from IBM, EMC, Sun and Copan, then EMC moves up to first or second, but then press release titles like "EMC a Leader in FalconStor-based non-mainframe Virtual Tape Libraries" can get too confusing.)
Chuck, if you are reading this, I feel you have every right to celebrate your involvement with the EDL. Despite having common software and hardware components, both IBM and EMC can rightfully declare their own unique value-add through their respective VTL offerings. Like the IBM N series, the EMC Disk Library is not diminished by the fact the software was written by someone else. BarryB might disagree.
The weather has warmed up here in Tucson so I started my Spring Cleaning early this year and unearthed from my garage a [Bankers Box] full of floppy diskettes.
IBM invented the floppy disk back in 1971, and continued to make improvements and enhancements through the 1980s and 1990s. It will be one of the many inventions celebrated as part of IBM's Centennial (100-year) anniversary. Here is an example [T-shirt]
IBM needed a way to send out small updates and patches for microcode of devices out in client locations. IBM had drives that could write information, and sent out "read-only" drives to the customer locations to receive these updates. These were flexible plastic circles with a magnetic coating, and placed inside a square paper sleeve. Imagine a floppy disk the size of a piece of standard paper. The 8-inch floppy fit conveniently in a manila envelope, sendable by standard mail, and could hold nearly 80KB of data.
I've been using floppies for the past thirty years. Here's some of my fondest memories:
While still in high school, my friend Franz Kurath and I formed "Pearson Kurath Systems", a software development firm. We wrote computer programs to run on UNIX and Personal Computers for small businesses here in Tucson. Whenever we developed a clever piece of code, a subroutine or procedure, we would save it on a floppy disk and re-use it for our next project. We wrote in the BASIC language, and our databases were simple Comma-Separated-Variable (CSV) flat files.
The 5.25-inch floppies we used could hold 360KB, and were flexible like the 8-inch models. Later versions of these 5.25-inch floppies would be able to hold as much as 1.2MB of data. We would convert single-sided floppies into double-sided ones by cutting out a notch in the outer sleeve. Covering up the notches would mark them as read-only.
The 3.5-inch floppies were introduced with a hard plastic shell, with the selling point that you can slap on a mailing label and postage and send it "as is" without the need for a separate envelope. These new 3.5-inch floppies would carry "HD" for high density 720KB, and double-sided versions could hold 1.44MB of data. The term "diskette" was used to associate these new floppies with [hard-shelled tape cassettes]. Sliding a plastic tab would allow floppies to be marked "read-only". IBM has the patent on this clever invention.
Continuing our computer programming business in college, Franz and I took out a bank loan to buy our first Personal Computer, for over $5000 dollars USD. Until then, we had to use equipment belonging to each client. The banks we went to didn't understand why we needed a computer, and suggested we just track our expenses on traditional green-and-white ledger paper. Back then, peronsal computers were for balancing your checkbook, playing games and organizing your collection of cooking recipies. But for us, it was a production machine. A computer with both 5.25-inch and 3.5-inch drives could copy files from one format to another as needed. The boost in productivity paid for itself within months.
Apple launched its Macintosh computer in 1984, with a built-in 3.5-inch disk drive as standard equipment. Here is a YouTube video of an [astronaut ejecting a floppy disk] from an Apple computer in space.
In my senior year at the University of Arizona, my roommate Dave had borrowed my backpack to hold his lunch for a bike ride. He thought he had taken everything out, but forgot to remove my 3.5-inch floppy diskette containing files for my senior project. By the time he got back, the diskette was covered in banana pulp. I was able to rescue my data by cracking open the plastic outer shell, cleaning the flexible magnetic media in soapy water, placing it back into the plastic shell of a second diskette, and then copied the data off to a third diskette.
After graduating from college, Franz and I went our separate ways. I went to work for IBM, and Franz went to work for [Chiat/Day], the advertising agency famous for the 1984 Macintosh commercial. We still keep in touch through Facebook.
At IBM, I was given a 3270 terminal to do my job, and would not be assigned a personal computer until years later. Once I had a personal computer at home and at work, the floppy diskette became my "briefcase". I could download a file or document at work, take it home, work on it til the wee hours of the morning, and then come back the next morning with the updated effort.
To help prepare me for client visits and public speaking at conferences, IBM loaned me out to local schools to teach. This included teaching Computer Science 101 at Pima Community College. When asked by a student whether to use "disc" or "disk", I wrote a big letter "C" on the left side of the chalkboard, and a big letter "K" on the right side. If it is round, I told the students while pointing at the letter "C", like a CD-ROM or DVD, use "disc". If it has corners, pointing to corners of the letter "K", like a floppy diskette or hard disk drive, use "disk".
On one of my business trips to visit a client, we discovered the client had experienced a problem that we had just recently fixed. Normally, this would have meant cutting a Program Trouble Fix (PTF) to a 3480 tape cartridge at an IBM facility, and send it to the client by mail. Unwilling to wait, I offered to download the PTF onto a floppy diskette on my laptop, upload it from a PC connected to their systems, and apply it there. This involved a bit of REXX programming to deal with the differences between ASCII and EBCDIC character sets, but it worked, and a few hours later they were able to confirm the fix worked.
In 1998, Apple would signal the begining of the end of the floppy disk era, announcing their latest "iMac" would not come with an internal built-in floppy drive. David Adams has a great article on this titled [The iMac and the Floppy Drive: A Conspiracy Theory]. You can get external floppy drives that connect via USB, so not having an internal drive is no longer a big deal.
While teaching a Top Gun class to a mix of software and hardware sales reps, one of the students asked what a "U" was. He had noticed "2U" and "3U" next to various products and wondered what that was referring to. The "U" represents the [standard unit of measure for height of IT equipment in standard racks]. To help them visualize, I explained that a 5.25-inch floppy disk was "3U" in size, and a 3.5-inch floppy diskette was "2U". Thus, a "U" is 1.75 inches, the thinnest dimension on a two-by-four piece of lumber. Servers that were only 1U tall would be referred to as "pizza boxes" for having similar dimensions.
Every year, right around November or so, my friends and family bring me their old computers for me to wipe clean. Either I would re-load them with the latest Ubuntu Linux so that their kids could use it for homework, or I would donate it to charity. Last November, I got a computer that could not boot from a CD-ROM, forcing me to build a bootable floppy. This gave me a chance to check out the various 1-disk and 2-disk versions of Linux and other rescue disks. I also have a 3-disk set of floppies for booting OS/2 in command line mode.
So while this unexpected box of nostalgia derailed my efforts to clean out my garage this weekend, it did inspire me to try to get some of the old files off them and onto my PC hard drive. I have already retrieved some low-res photographs, some emails I sent out, and trip reports I wrote. While floppy diskettes were notorious for being unreliable, and this box of floppies has been in the heat and cold for many Arizonan summers and winters, I am amazed that I was able to read the data off most of them so far, all the way back to data written in 1989. While the data is readable, in most cases I can't render it into useful information. This brings up a few valuable lessons:
Backups are not Archives
Some of the files are in proprietary formats, such as my backups for TurboTax software. I would need a PC running a correct level of Windows operating system, and that particular software, just to restore the data. TurboTax shipped new software every year, and I don't know how forward or backward-compatible each new release was.
Another set of floppies are labeled as being in "FDBACK" format. I have no idea what these are. Each floppy has just two files, "backup.001" and "control.001", for example.
Backups are intended solely to protect against unexpected loss from broken hardware or corrupted data. If you plan to keep data as archives for long-term retention, use archive formats that will last a long time, so that you can make sense of them later.
Operating System Compatibility
Windows 7 and all of my favorite flavors of Linux are able to recognize the standard "FAT" file system that nearly all of my floppies are written in. Sadly, I have some files that were compressed under OS/2 operating system using software called "Stacker". I may have to stand up an OS/2 machine just to check out what is actually on those floppies.
You can't judge a book by its cover
Floppies were a convenient form of data interchange. Sometimes, I reused commercially-labeled floppies to hold personal files. So, just because a floppy says "America On-Line (AOL) version 2.5 Installation", I can't just toss it away. It might actually contain something else entirely. This means I need to mount each floppy to check on its actual contents.
So what will I do with the floppies I can't read, can't write, and can't format? I think I will convert them into a [retro set of coasters], to protect my new living room furniture from hot and cold beverages.
Well, it's Tuesday, and so it is "announcement day" again! Actually, for me it is Wednesday morning herein Mumbai, India, but since I was "press embargoed" until 4pm EDT in talking about these enhancements, I had to wait until Wednesday morning here to talk about them.
World's Fastest 1TB tape drive
IBM announced its new enterprise [TS1130 tape drive]and corresponding [TS3500 tape library support]. This one has a funny back-story. Last week while we were preparing the Press Release, we debated on whether we should compare the 1TB per cartridge capacity as double that of Sun's Enterprise T10000 (500GB), or LTO-4 (800GB). The problem changed when Sun announced on Monday they too had a 1TB tape drive, so now instead ofsaying that we had the "World's First 1TB tape drive", we quickly changed this to the "World's Fastest 1TB tape drive" instead. At 160MB/sec top speed, IBM's TS1130 is 33 percent faster than Sun's latest announcement. Sun was rather vague when they will actually ship their new units, so IBM may still end up being first to deliver as well.
While EMC and other disk-only vendors have stopped claiming that "tape is dead", these recent announcements from IBM and Sun indicate that indeed tape is alive and well. IBM is able to borrow technologies from disk, such as the Giant Magneto Resistive (GMR) head over to its tape offerings, which means much of the R&D for disk applies to tape, keeping both forms ofstorage well invested. Tape continues to be the "greenest" storage option, more energy efficient than disk, optical, film, microfiche and even paper.
On the LTO front, IBM enhanced the reporting capabilities of its[TS3310] midrange tape library. This includes identifying the resource utilization of the drives, reporting on media integrity, and improved diagnostics to support library-managed encryption.
IBM System Storage DR550
As a blended disk-and-tape solution, the [IBM System Storage DR550] easily replaces the EMC Centera to meet compliance storagerequirements. IBM announced that we have greatly expanded its scalability, being able to support both 1TBdisk drives, as well as being able to attach to either IBM or Sun's 1TB tape drives.
Massive Array of Idle Disks (MAID)
IBM now offers a "Sleep Mode" in the firmware of the [IBM System Storage DCS9550], which is often called "Massive Array of Idle Disks" (MAID) or spin-down capability. This can reduce the amount of power consumed during idle times.
That's a lot of exciting stuff. I'm off to breakfast now.
He feels I was unfair to accuse EMC of "proprietary interfaces" without spelling out what I was referring to. Here arejust two, along with the whines we hear from customers that relate to them.
EMC Powerpath multipathing driver
Typical whine: "I just paid a gazillion dollars to renew my annual EMC Powerpath license, so you will have to come back in 12 months with your SVC proposal. I just can't see explaining to my boss that an SVC eliminates the need for EMC Powerpath, throwing away all the good money we just spent on it, or to explain that EMC chooses not to support SVC as one of Powerpath's many supported devices."
EMC SRDF command line interface
Typical whine: "My storage admins have written tons of scripts that all invoke EMC SRDF command line interfacesto manage my disk mirroring environment, and I would hate for them to re-write this to use IBM's (also proprietary) command line interfaces instead."
Certainly BarryB is correct that IBM still has a few remaining "proprietary" items of its own. IBM has been in business over 80 years, but it was only the last 10-15 years that IBM made a strategic shift away from proprietary and over to open standards and interfaces. The transformation to "openness" is not yet complete, but we have made great progress. Take these examples:
The System z mainframe - IBM had opened the interfaces so that both Amdahl and Fujitsu made compatible machines.Unlike Apple which forbids cloning of this nature, IBM is now the single source for mainframes because the other twocompetitors could not keep up with IBM's progress and advancements in technology.
Update: Due to legal reasons, the statements referring to Hercules and other S/390 emulators havebeen removed.
The z/OS operating system - While it is possible to run Linux on the mainframe, most people associate the z/OSoperating system with the mainframe. This was opened up with UNIX System Services to satisfy requests from variousgovernments. It is now a full-fledged UNIX operating system, recognized by the [Open Group] that certifies it as such.
As BarryB alludes, the unique interfaces for disk attachment to System z known as Count-Key-Data (CKD) was published so that both EMC and HDS can offer disk systems to compete with IBM's high-end disk offerings. Linux on System zsupports standard Fibre Channel, allowing you to attach an IBM SVC and anyone's storage. Both z/OS and Linux on System z support NAS storage, so IBM N series, NetApp, even EMC Celerra could be used in that case.
The System i itself is still proprietary, but recently IBM announced that it will now support standard block size (512 bytes) instead of the awkward 528 byte blocks that only IBM and EMC support today. That means that any storage vendor will be ableto sell disk to the System i environment.
Advanced copy services, like FlashCopy and Metro Mirror, are as proprietary as the similar offerings from EMCand HDS, with the exception that IBM has licensed them to both EMC and HDS. Thanks to cross-licensing, you can do [FlashCopy on EMC] equipment. Getting all the storage vendors to agree to open standards for these copy services is still workin progress under [SNIA], but at least people who have coded z/OS JCL batchjobs that invoke FlashCopy utilities can work the same between IBM and EMC equipment.
So for those out there who thought that my comment about EMC's proprietary interfaces in any way implied thatIBM did not have any of its own, the proverbial ["pot calling the kettle black"] so to speak, I apologize.
BarryB shows off his [PhotoShop skills] with the graphic below. I take it as a compliment to be compared to anAll-American icon of business success.
TonyP and Monopoly's Mr. Pennybags Separated at Birth?
However, BarryB meant it as a reference back to long time ago when IBMwas a monopoly of the IT industry, which according to [IBM's History], ended in 1973. In other words, IBMstopped being a monopoly before EMC ever existed as a company, and long before I started working for IBM myself.
The anti-trust lawsuit that BarryB mentions happened in 1969, which forced IBM to separate some of the software from its hardware offerings, and prevented IBM from making various acquisitions for years to follow, forcing IBM instead into technology partnerships. I'm glad that's all behind us now!
Well, it's Tuesday again, and that means more announcements from IBM!
In conjunction with IBM's new [System z10 Business Class (BC)] mainframe designed for Small and Medium-sized Businesses (SMB), IBM also announced related storage productenhancements.
Yes, it's alive! Contrary to the FUD you might have read from our competitors, IBM continues to sell thousands and thousands of IBM System Storage DS6800 disk systems, and now enhances them with the optionfor 450GB 15K RPM drives. What is nice about these 450GB drives is that they are as fast or faster* than 300GBdrives, so the typical trade-off between performance and capacity do not apply.
(* I compared Seagate 15.6K (450GB) with 15.5K (300GB) models.
Avg Seek time (Read)
Avg Seek time (Write)
Full Seek time (Read)
Full Seek time (Write)
This may or may not result in application performance improvements, depending on workload pattern. Your mileage may vary.)
Our clients report back that these are incredibly stable systems that they don't have toworry about. This enhancement applies to both the [511/EX1 models] and [522/EX2 models].
Understanding that clients want complete solutions from single vendors, IBM offers synergy between System z and the IBM System Storage DS8000 disk systems. The latest R4.1 microcode upgrade offers two key features onthe various models [2107,
zHPF - High Performance FICON for System z. IBM was able to increase the throughput on 4 Gbps links. For OLTP workloads randomly accessing 4KB blocks, IBM internal tests showed zHPF doubled performance from 13,000 IOPSto 26,000 IOPS per channel. For sequential workloads, such as batch processing, zHPF increased performance 50 percent, from 350 MB/sec to 525 MB/sec.
In February, IBM previewed[IncrementalResync] for z/OS Metro Global Mirror. However, some concepts are better explained with pictures.
One way to set up a 3-site disaster recovery protection is to have your production synchronously mirrored to a second site nearby, and at the same time asynchronously mirrored to a remote location. On the System z, you can have site "A" using synchronous IBM System Storage Metro Mirror over to nearby site "B", and also have site "A" sending data over to site "C" asynchronously using z/OS Global Mirror. This is called "z/OS Metro Global Mirror".
In the past, if the disk system in site A failed, you would switch over to site B, which would have to resend send all the data again to site C to be resynchronized. This is because site B was not tracking what the System Data Mover (SDM) reader had or had not yet processed.
With DS8000 4.1, the "incremental resync" function that, along with using IBM HyperSwap, requires site B to only send and resync the data that was in-flight when the outage occurred. When you compare the difference in sending this limited amount of in-flight data with the traditional complete volume of data, you can see how "Incremental Resync" can resynchronize the data 95% faster, and also greatly decrease your bandwidth requirements. This reduces the risk in case a subsequent outage occurs.
Introduced originally in 1997 as the IBM Virtual Tape Server (VTS), the [IBMSystem Storage TS7700] series supports Grid capabilityto replicate tape image data across locations. Here's a quick recap of today's announcement:
Existing TS7740 can be upgraded up to 9TB of disk cache. New models can have up to 13TB of disk cache.
A new "tape-less" TS7720 that has up to 70TB of disk cache.
Integrate Library Management support. I discussed[IntegratedRemovable Media Manager (IRMM)] before, and this is basically IRMM inside. For those with TS3500 tape libraries,this support eliminates the need for a separate IBM 3953 L05 Library Manager.
TS1130 back-end tape drive support. These are the fastest 1TB drives in the industry, with support of built-in encryption, and now can be used asthe physical tape back-end for the virtual tape TS7740 repository.
While our competitors might be boarding up their windows in preparation for the economic downturn in the USAeconomy, IBM remains generating solid results. San Jose Mercury News has an article that discusses this titled[IBM's 3Q profit strong on global sales].There has never been a better time to buy from, or invest in, IBM!
Well, this week I am in Maryland, just outside of Washington DC. It's a bit cold here.
Robin Harris over at StorageMojo put out this Open Letter to Seagate, Hitachi GST, EMC, HP, NetApp, IBM and Sun about the results of two academic papers, one from Google, and another from Carnegie Mellon University (CMU). The papers imply that the disk drive module (DDM) manufacturers have perhaps misrepresented their reliability estimates, and asks major vendors to respond. So far, NetAppand EMC have responded.
I will not bother to re-iterate or repeat what others have said already, but make just a few points. Robin, you are free to consider this "my" official response if you like to post it on your blog, or point to mine, whatever is easier for you. Given that IBM no longer manufacturers the DDMs we use inside our disk systems, there may not be any reason for a more formal response.
Coke and Pepsi buy sugar, Nutrasweet and Splenda from the same sources
Somehow, this doesn't surprise anyone. Coke and Pepsi don't own their own sugar cane fields, and even their bottlers are separate companies. Their job is to assemble the components using super-secret recipes to make something that tastes good.
IBM, EMC and NetApp don't make DDMs that are mentioned in either academic study. Different IBM storage systems uses one or more of the following DDM suppliers:
Seagate (including Maxstor they acquired)
Hitachi Global Storage Technologies, HGST (former IBM division sold off to Hitachi)
In the past, corporations like IBM was very "vertically-integrated", making every component of every system delivered.IBM was the first to bring disk systems to market, and led the major enhancements that exist in nearly all disk drives manufactured today. Today, however, our value-add is to take standard components, and use our super-secret recipe to make something that provides unique value to the marketplace. Not surprisingly, EMC, HP, Sun and NetApp also don't make their own DDMs. Hitachi is perhaps the last major disk systems vendor that also has a DDM manufacturing division.
So, my point is that disk systems are the next layer up. Everyone knows that individual components fail. Unlike CPUs or Memory, disks actually have moving parts, so you would expect them to fail more often compared to just "chips".
If you don't feel the MTBF or AFR estimates posted by these suppliers are valid, go after them, not the disk systems vendors that use their supplies. While IBM does qualify DDM suppliers for each purpose, we are basically purchasing them from the same major vendors as all of our competitors. I suspect you won't get much more than the responses you posted from Seagate and HGST.
American car owners replace their cars every 59 months
According to a frequently cited auto market research firm, the average time before the original owner transfers their vehicle -- purchased or leased -- is currently 59 months.Both studies mention that customers have a different "definition" of failure than manufacturers, and often replace the drives before they are completely kaput. The same is true for cars. Americans give various reasons why they trade in their less-than-five-year cars for newer models. Disk technologies advance at a faster pace, so it makes sense to change drives for other business reasons, for speed and capacity improvements, lower power consumption, and so on.
The CMU study indicated that 43 percent of drives were replaced before they were completely dead.So, if General Motors estimated their cars lasted 9 years, and Toyota estimated 11 years, people still replace them sooner, for other reasons.
At IBM, we remind people that "data outlives the media". True for disk, and true for tape. Neither is "permanent storage", but rather a temporary resting point until the data is transferred to the next media. For this reason, IBM is focused on solutions and disk systems that plan for this inevitable migration process. IBM System Storage SAN Volume Controller is able to move active data from one disk system to another; IBM Tivoli Storage Manager is able to move backup copies from one tape to another; and IBM System Storage DR550 is able to move archive copies from disk and tape to newer disk and tape.
If you had only one car, then having that one and only vehicle die could be quite disrupting. However, companies that have fleet cars, like Hertz Car Rentals, don't wait for their cars to completely stop running either, they replace them well before that happens. For a large company with a large fleet of cars, regularly scheduled replacement is just part of doing business.
This brings us to the subject of RAID. No question that RAID 5 provides better reliability than having just a bunch of disks (JBOD). Certainly, three copies of data across separate disks, a variation of RAID 1, will provide even more protection, but for a price.
Robin mentions the "Auto-correlation" effect. Disk failures bunch up, so one recent failure might mean another DDM, somewhere in the environment, will probably fail soon also. For it to make a difference, it would (a) have to be a DDM in the same RAID 5 rank, and (b) have to occur during the time the first drive is being rebuilt to a spare volume.
The human body replaces skin cells every day
So there are individual DDMs, manufactured by the suppliers above; disk systems, manufactured by IBM and others, and then your entire IT infrastructure. Beyond the disk system, you probably have redundant fabrics, clustered servers and multiple data paths, because eventually hardware fails.
People might realize that the human body replaces skin cells every day. Other cells are replaced frequently, within seven days, and others less frequently, taking a year or so to be replaced. I'm over 40 years old, but most of my cells are less than 9 years old. This is possible because information, data in the form of DNA, is moved from old cells to new cells, keeping the infrastructure (my body) alive.
Our clients should approach this in a more holistic view. You will replace disks in less than 3-5 years. While tape cartridges can retain their data for 20 years, most people change their tape drives every 7-9 years, and so tape data needs to be moved from old to new cartridges. Focus on your information, not individual DDMs.
What does this mean for DDM failures. When it happens, the disk system re-routes requests to a spare disk, rebuilding the data from RAID 5 parity, giving storage admins time to replace the failed unit. During the few hours this process takes place, you are either taking a backup, or crossing your fingers.Note: for RAID5 the time to rebuild is proportional to the number of disks in the rank, so smaller ranks can be rebuilt faster than larger ranks. To make matters worse, the slower RPM speeds and higher capacities of ATA disks means that the rebuild process could take longer than smaller capacity, higher speed FC/SCSI disk.
According to the Google study, a large portion of the DDM replacements had no SMART errors to warn that it was going to happen. To protect your infrastructure, you need to make sure you have current backups of all your data. IBM TotalStorage Productivity Center can help identify all the data that is "at risk", those files that have no backup, no copy, and no current backup since the file was most recently changed. A well-run shop keeps their "at risk" files below 3 percent.
So, where does that leave us?
ATA drives are probably as reliable as FC/SCSI disk. Customers should chose which to use based on performance and workload characteristics. FC/SCSI drives are more expensive because they are designed to run at faster speeds, required by some enterprises for some workloads. IBM offers both, and has tools to help estimate which products are the best match to your requirements.
RAID 5 is just one of the many choices of trade-offs between cost and protection of data. For some data, JBOD might be enough. For other data that is more mission critical, you might choose keeping two or three copies. Data protection is more than just using RAID, you need to also consider point-in-time copies, synchronous or asynchronous disk mirroring, continuous data protection (CDP), and backup to tape media. IBM can help show you how.
Disk systems, and IT environments in general, are higher-level concepts to transcend the failures of individual components. DDM components will fail. Cache memory will fail. CPUs will fail. Choose a disk systems vendor that combines technologies in unique and innovative ways that take these possibilities into account, designed for no single point of failure, and no single point of repair.
So, Robin, from IBM's perspective, our hands are clean. Thank you for bringing this to our attention and for giving me the opportunity to highlight IBM's superiority at the systems level.
Earlier this week, EMC announced its Symmetrix V-Max, following two trends in the industry:
Using Roman numerals. The "V" here is for FIVE, as this is the successor to the DMX-3 and DMX-4. EMC might have gotten the idea from IBM's success with the XIV (which does refer to the number 14, specifically the 14th class of a Talpiot program in Israel that the founders of XIV graduated from).
Adding "-Max", "-Monkey" or "2.0" at the end of things to make them sound more cool and to appeal to a younger, hipper audience. EMC might have gotten this idea from Pepsi-Max (... a taste of storage for the next generation?)
I took a cue from President Obama and waited a few days to collect my thoughts and do my homework before responding.Special thanks to fellow blogger ChuckH in giving me a [handy list of reactions] for me to pick and choose from. It appears that EMC marketing machine feels it is acceptable for their own folks to claim that EMC is doing something first, or that others are catching up to EMC, but when other vendors do likewise, then that is just pathetic or incoherent. Here are a few reactions already from fellow bloggers:
This was a major announcement for EMC, addressing many of the problems, flaws and weaknesses of the earlier DMX-3 and DMX-4 deliverables. Here's my read on this:
Now you can have as many FCP ports (128) as an IBM System Storage DS8300, although the maximum number of FICON ports is still short, and no mention of ESCON support. The Ethernet ports appear to be 1Gb, not the new 10GbE you might expect.
Support for System z mainframe
V-Max adds some new support to catch up with the DS8000, like Extended Address Volumes (EAV). EMC is still not quite there yet. IBM DS8000 continues to be the best, most feature-rich storage option if you have System z mainframe servers.
Both the IBM DS8000 and HDS USP-V beat the DMX-4 in performance, and in some cases the DMX-4 even lost to the IBM XIV, so EMC had to do something about it. EMC chooses not to participate in industry-standard performance benchmarks like those from the [Storage Performance Council], which limits them to vague comparisons against older EMC gear. I'll give EMC engineers the benefit of the doubt and say that now V-Max is now "comparably as fast as HDS and IBM offerings".
Getting "V" in the name
The "V" appears to be for the roman number five, not to be confused with external heterogeneous storage virtualization that HDS USP-V and IBM SVC provide. There is no mention of synergy with EMC's failed "Invista" product, and I see no support for attaching other vendors disk to the back of this thing.
Switch to Intel processor
Apple switched its computers from PowerPC to Intel-based, and now EMC follows in the same path. There are some custom ASICs still in V-Max, so it is not as pure as IBM's offerings.
Modular, XIV-like Scale-out Architecture
Actually, the packaging appears to follow the familiar system bays and storage bays of the DMX-4 and DMX-4 950 models, but architecturally offers XIV-like attachment across a common switch network between "engines", EMC's term for interface modules.
Non-disruptive data migration
IBM's SoFS, DR550 and GMAS have this already, as does as anything connected behind an IBM SAN Volume Controller.
A long time ago, IBM used to have midrange disk storage systems called "FAStT" which stood for Fibre Array Storage Technology, so this might have given EMC the idea for their "Fully Automated Storage Tiering" acronym. The concept appears similar to what IBM introduced back in 2007 for the Scale-Out-File Services [SofS] which not only provides policy-based placement, movement and expiration on different disk tiers, includes tape tiers as well for a complete solution. I don't see anything in the V-Max announcement that it will support tape anytime soon.
And what ever happend to EMC's Atmos? Wasn't that supposed to be EMC's new direction in storage?
Zero-data loss Three-site replication
IBM already calls this Metro/Global Mirror for its IBM DS8000 series, but EMC chose to call it SRDF/EDP for Extended Distance Protection.
Ease of Use
The most significant part of the announcement is that EMC is finally focusing on ease-of-use.In addition to reducing the requirement for "Bin File" modifications, this box has a redesigned user interface to focus on usability issues. For past DMX models, EMC customers had to either hire EMC to do tasks for them that were just to difficult otherwise, or buy expensive software like their EMC Control Center to manage. EMC willcontinue to sell DMX-4 boxes for a while, as they are probably supply-constrained on the V-Max side, but I doubt they will retro-fit these new features back to DMX-3 and DMX-4.
When IBM announced its acquisition of XIV over a year ago now, customers were knocking down our doors to get one. This caught two particular groups looking like a [deer in headlights]:
EMC Symmetrix sales force: Some of the smarter ones left EMC to go sell IBM XIV, leaving EMC short-handed and having to announce they [were hiring during their layoffs]. Obviously, a few of the smart ones stayed behind, to convince their management to build something like the V-Max.
IBM DS8000 sales force: If clients are not happy with their existing EMC Symmetrix, why don't they just buy an IBM DS8000 instead? What does XIV have that DS8000 doesn't?
Let me contrast this with the situation Microsoft Windows is currently facing.
I am often asked by friends to help them pick out laptops and personal computers. I use Linux, Windows and MacOS, so have personal experience with all three operating systems.
Linux is cheaper, offers the power-user the most options for supporting older, less-powerfulequipment, but I wouldn't have my Mom use it. While distributions like Ubuntu are makinggreat strides, it is just too difficult for some people.
MacOS is nice, I like it, it works out of the box with little or no customization and an intuitive interface. However, some of my friends don't make IBM-level salaries, and have to watch their budget.
In their "I'm a PC" campaign, Microsoft is fighting both fronts. Let's examine two commercials:
In the first commercial, a young eight-year-old puts together a video from pictures oftoy animals and some background music.The message: "Windows is easier to use than Linux!" If they really wanted to send this message, they should have shown senior citizens instead.
In the second commercial, a young college student is asked to find a laptop with 17 inchscreen, and a variety of other qualifications, for under $1000 US dollars. The only modelat the Apple store below this price had a 13 inch screen, but she finds a Windows-based system that had this size screen and met all the other qualifications. The message: "Windows-based hardware from a variety of competitors are less expensive than hardware from Apple!"
Both Microsoft and Apple charge a premium for ease-of-use.In the storage world, things are completely opposite. Vendors don't charge a premium forease-of-use. In fact, some of the easiest to use are also the least expensive.
If you just have Windows and Linux, you can get some entry level system likethe IBM DS3000 series, only a few features, and can be set up in six simple steps.
Next, if you have a more interesting mix of operating systems, Linux, Windows and some flavorsof UNIX like IBM AIX, HP-UX or Sun Solaris, then you might want the features and functionsof more pricier midrange offerings. More options means that configuration and deploymentis more difficult, however.
Finally, if you are serious Fortune 500 company, running your mission critical applications on System z or System i centralized systems in a big data center, that you might be willing to pay top dollar for the most feature-rich offerings of an Enterprise-class machine.Thankfully you have an army of highly-trained staff to handle the highest levels of complexity.
IBM's DS8000, HDS USP-V and EMC's Symmetrix are the key players in the Enterprise-classspace. They tried to be ["all things to all people"], er.. perhaps all things to allplatforms. All of the features and functions came at a price, not just in dollars, butin complexity and difficulty. You needed highly skilled storage admins using expensive storage management software, or be willing to hirethe storage vendor's premium services to get the job done.
IBM recognized this trend early. IBM's SVC, N series and now XIV all offer ease-of-use withenterprise-class features and functions, at lower total cost of ownership than traditional enterprise-class systems. IBM is not the only one, of course, as smaller storage start-ups like 3PAR,Pillar Data Systems, Compellent, and to some extent Dell's EqualLogic all recognized thisand developed clever offerings as well.
While IBM's XIV may not have been the first to introduce a modular, scale-out architectureusing commodity parts managed by sophisticated ease-of-use interfaces, its success might have been the kick-in-the-butt EMC needed to follow the rest of the industry in this direction.
I'm glad to be back home in Tucson for a few weeks. All of these conferences kept mefrom reading up with what was going on in the blogosphere.
A few of us at IBM found it odd that EMC would announce their new Geographically Dispersed Disaster Restart (GDDR) the weekBEFORE their "EMC World" conference. Why not announce all of the stuff all at once instead at the conference?Were they worried that the admission that "Maui" software is still many months awaythat much of a negative stigma? The decision probably went something like this:
EMCer #1: GDDR is finally ready, should we announce now, or wait ONE week to make it part of the thingswe announce at EMC World?
EMCer #2: We are not announcing much at EMC World and what people really want us to talk about, Maui, wearen't delivering for a while. Why can't people understand we are company of hardware engineers, not software programmers! So, better not be associated with that quagmire at all.
EMCer #1: Yes, boss, I see your point. We'll announce this week then.
My fellow blogger and intellectual sparring partner, Barry Burke, on his Storage Anarchist blog, posted [are you wasting money on your mainframe dr solution?"] to bringup the GDDR announcement. The key difference is that IBM GDPS works withIBM, EMC and HDS equipment, being the fair-and-balanced folks that IBM clientshave come to expect, but it appears EMC GDDR works only with EMC equipment.Because GDDR does less, it also costs less. I can accept that. You get whatyou pay for. Of course, IBM does have a variety of protection levels, one probably will meet your budget and your business continuity needs.
To correct Barry's misperception, companies that buy IBM mainframe servers do have a choice.They can purchase their operating system from IBM, get their Linux or OpenSolarisfrom someone else like Red Hat or Novell, or build their own OS distribution fromreadily available open source. And unlike other servers that might require at leastone OS partition from the vendor, IBM mainframes can run 100 percent Linux.GDPS supports a mix of OS data. z/OS and Linux data can all be managed by GDPS.Companies that own mainframes know this. I can forgive the misperception from Barry,as EMC is focused on distributed servers instead, and many in their company may not have muchexposure to mainframe technology, or have ever spoken to mainframe customers.
But what almost had me fall out of my chair was this little nugget from his post:
"If you're an IBM mainframe customer, you are - by definition - IBM's profit stream."
Honestly, is there anyone out there that does not realize that IBM is a for-profitcorporation? In contrast, Barry would like his readers to believe that EMC is selling GDDR at cost, andthat EMC is a non-profit organization. While IBM has been delivering actual solutions thatour clients want, EMC continues to rumor that someday they might get around to offering something worthwhile.In the last six months, the shareholders have interpreted both strategies for what they really are,and the stock prices reflect that:
(Disclosure: I own IBM stock. I do not own EMC stock. Stock price comparisonsby Yahoo were based on publicly reported information. The colors blue and red to represent IBM and EMC, respectively, were selected by Yahoo graph-making facility. The color red does not necessarily imply EMC is losing money or having financial troubles.)
Of course, I for one would love to help Barry's dream of EMC non-profitability come true. If anyone has any suggestions how we can help EMC approach this goal, please post a comment below.
Last July, IBM and EMC traded blog postings over SPC-1 benchmark results. Fellow EMC bloggerChuck Hollis wrote his post [Does Anyone Take The SPC Seriously?]. Here is an excerpt:
I think most storage users have figured this out. We've never done an SPC test, and probably will never do one. Anyone is free, however, to download the SPC code, lash it up to their CLARiiON, and have at it.
I responded with [Getting Under EMC Skin], and then followed up with a series explaining IBM SVC and SPC benchmarks here:
So what is the good news?Yesterday, our friends at NetApp took up Chuck's challenge and posted results on their FAS3040 as well as their EMC CLARiiON devices. IBM sells the FAS3040 under the name IBM System Storage N5300 disk system. Knowing that NetApp maintains excellent performance when it is doing point-in-time copies, NetApp ran both with and without on both boxes. I include DS4700 and DS4800 as well for comparison purposes, but only have them without FlashCopy running.
NetApp FAS3040 (IBM N5300)
NetApp FAS3040 (IBM N5300)
EMC CLARiiON CX3-40
IBM DS4700 Express
EMC CLARiiON CX3-40
One would expect some performance degradation with a box running point-in-time copies at the same time it is reading and writing data, but NetApp/IBM N5300 does not degrade by much, but EMC's drops a significant amount.
So what is the bad news? Last October, I welcomed HDS USP-V to the [Super High-End Club], but now we need to invite Texas Memory Systems as well.In 2006, I posted [Hybrid, Solid State and the future of RAID], and poked fun at Texas Memory Systems using the slogan "World's Fastest Storage", which at the time that honor belonged to IBM SAN Volume Controller instead.The VP of Texas Memory Systems, Woody Hutsell, explained the only reason their solid-state disk system, RAMSAN-320, didn't have faster results is that they didn't have the fastest IBM server to run against it. It may not surprise you that nearly everyone's SPC benchmarks use IBM servers because IBM has the fastest servers as well. I didn't have a million-dollar System p UNIX server to send Woody for this, but it looks like they have finally gotten one, and a new RAMSAN-400 device, as they have posted their latest results.
Texas Memory Systems RAMSAN-400
IBM SAN Volume Controller 4.2
EMC doesn't publish numbers for their Symmetrix box, despite their announcement of faster SSD drives. They claim that SSD drives make their overall disk system performance faster, but without SPC benchmarks, we will never know. If you have a Symmetrix, this YouTube video may help you decide where it belongs:
Continuing my ongoing discussion on Solid State Disk (SSD), fellow blogger BarryB (EMC) points out in his [latest post]:
Oh – and for the record TonyP, I don't think I ever said EMC was using a newer or different EFDs than IBM. I just asserted that EMC knows more than IBM about these EFDs and how they actually work a storage array under real-world workloads.
(Here "EFD" is refers to "Enterprise Flash Drive", EMC's marketing term for Single Layer Cell (SLC) NAND Flash non-volatile solid-state storage devices. Both IBM and EMC have been selling solid-state storage for quite some time now, but EMC felt that a new term was required to distinguish the SLC NAND Flash devices sold in their disk systems from solid-state devices sold in laptops or blade servers. The rest of the industry, including IBM, continues to use the term SSD to refer to these same SLC NAND Flash devices that EMC is referring to.)
Although STEC asserts that IBM is using the latest ZeusIOPS drives, IBM is only offering the 73GB and 146GB STEC drives (EMC is shipping the latest ZeusIOPS drives in 200GB and 400GB capacities for DMX4 and V-Max, affording customers a lower $/GB, higher density and lower power/footprint per usable GB.)
Here is where I enjoy the subtleties between marketing and engineering. Does the above seem like he is saying EMC is using newer or different drives? What are typical readers expected to infer from the statement above?
That there are four different drives from STEC, in four different capacities. In the HDD world, drives of different capacities are often different, and larger capacities are often newer than those of smaller capacities.
That the 200GB and 400GB are the latest drives, and that 73GB and 146GB drives are not the latest.
That STEC press release is making false or misleading claims.
Uncontested, some readers might infer the above and come to the wrong conclusions. I made an effort to set the record straight. I'll summarize with a simple table:
Usable (conservative format)
Usable (aggressive format)
So, we all agree now that the 256GB drives that are formatted as 146GB or 200GB are in fact the same drives, that IBM and EMC both sell the latest drives offered by STEC, and that the STEC press release was in fact correct in its claims.
I also wanted to emphasize that IBM chose the more conservative format on purpose. BarryB [did the math himself] and proved my key points:
Under some write-intensive workloads, an aggressive format may not last the full five years. (But don't worry, BarryB assures us that EMC monitors these drives and replaces them when they fail within the five years under their warranty program.)
Conservative formats with double the spare capacity happen to have roughly double the life expectancy.
I agree with BarryB that an aggressive format can offer a lower $/GB than the conservative format. Cost-conscious consumers often look for less-expensive alternatives, and are often willing to accept less-reliable or shorter life expectancy as a trade-off. However, "cost-conscious" is not the typical EMC targeted customer, who often pay a premiumfor the EMC label. To compensate, EMC offers RAID-6 and RAID-10 configurations to provide added protection. With a conservative format, RAID-5 provides sufficient protection.
(Just so BarryB won't accuse me of not doing my own math, a 7+P RAID-5 using conservative format 146GB drives would provide 1022GB of capacity, versus 4+4 RAID-10 configuration using aggressive format 200GB drives only 800GB total.)
In an ideal world, you the consumer would know exactly how many IOPS your application will generate over the next five years, exactly how much capacity you will require, be offered all three drives in either format to choose from, and make a smart business decision. Nothing, however, is ever this simple in IT.
"The murals in restaurants are on par with the food in museums." --- Peter De Vries
The quote above applies to blogs as well. Those about competitive products of which the blogger has little to no hands-on experience tend to be terribly misleading or technically inaccurate. We saw this last month as Sun Microsystems' Jeff Savit tried to discuss the IBM System z10 EC mainframe.
This time, it comes from EMC bloggers discussing NetApp equipment, and by association, IBM System Storage N series gear.I was going to comment on the ridiculous posts by fellow bloggers from EMC about SnapLock compliance feature on the NetApp, but my buddies at NetApp had already done this for me, saving me the trouble.
The hysterical nature of writing from EMC, and the calm responses from NetApp, speak volumes about the culturesof both companies.
The key point is that none of the "Non-erasable, Non-Rewriteable" (NENR) storage out there are certified as compliant by any government agency on the planet. Governments just aren't in the business of certifying such things. The best you can get is a third-party consultant, such as [Cohasset Associates], to help make decisions that are best for each particular situation.
In addition to SnapLock on N series, IBM offers the [IBM System Storage DR550], WORM tape and optical systems, all of which have been deemed compliant to the U.S. Securities and Exchange Commission [SEC 17a-4] federal regulations by Cohasset Associates. For medical patient records and images like X-rays, IBM offers the Grid Medical Archive Solution [GMAS]designed to meet the requirements of the U.S. Health Insurance Portability and Accountability Act[HIPAA].For other government or industry regulations, consult with your legal counsel.