Tony Pearson is a Master Inventor and Senior IT Architect for the IBM Storage product line at the
IBM Systems Client Experience 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 )
My books are available on Lulu.com! Order your copies today!
Safe Harbor Statement: The information on IBM products is intended to outline IBM's general product direction and it should not be relied on in making a purchasing decision. The information on the new products is for informational purposes only and may not be incorporated into any contract. The information on IBM products is not a commitment, promise, or legal obligation to deliver any material, code, or functionality. The development, release, and timing of any features or functionality described for IBM products remains at IBM's sole discretion.
Tony Pearson is a an active participant in local, regional, and industry-specific interests, and does not receive any special payments to mention them on this blog.
Tony Pearson receives part of the revenue proceeds from sales of books he has authored listed in the side panel.
Tony Pearson is not a medical doctor, and this blog does not reference any IBM product or service that is intended for use in the diagnosis, treatment, cure, prevention or monitoring of a disease or medical condition, unless otherwise specified on individual posts.
Wrapping up my week's theme of storage optimization, I thought I would help clarify the confusion between data reduction and storage efficiency. I have seen many articles and blog posts that either use these two terms interchangeably, as if they were synonyms for each other, or as if one is merely a subset of the other.
Data Reduction is LOSSY
By "Lossy", I mean that reducing data is an irreversible process. Details are lost, but insight is gained. In his paper, [Data Reduction Techniques", Rajana Agarwal defines this simply:
"Data reduction techniques are applied where the goal is to aggregate or amalgamate the information contained in large data sets into manageable (smaller) information nuggets."
Data reduction has been around since the 18th century.
Take for example this histogram from [SearchSoftwareQuality.com]. We have reduced ninety individual student scores, and reduced them down to just five numbers, the counts in each range. This can provide for easier comprehension and comparison with other distributions.
The process is lossy. I cannot determine or re-create an individual student's score from these five histogram values.
This next example, complements of [Michael Hardy], represents another form of data reduction known as ["linear regression analysis"]. The idea is to take a large set of data points between two variables, the x axis along the horizontal and the y axis along the vertical, and find the best line that fits. Thus the data is reduced from many points to just two, slope(a) and intercept(b), resulting in an equation of y=ax+b.
The process is lossy. I cannot determine or re-create any original data point from this slope and intercept equation.
In this last example, from [Yahoo Finance], reduces millions of stock trades to a single point per day, typically closing price, to show the overall growth trend over the course of the past year.
The process is lossy. Even if I knew the low, high and closing price of a particular stock on a particular day, I would not be able to determine or re-create the actual price paid for individual trades that occurred.
Storage Efficiency is LOSSLESS
By contrast, there are many IT methods that can be used to store data in ways that are more efficient, without losing any of the fine detail. Here are some examples:
Thin Provisioning: Instead of storing 30GB of data on 100GB of disk capacity, you store it on 30GB of capacity. All of the data is still there, just none of the wasteful empty space.
Space-efficient Copy: Instead of copying every block of data from source to destination, you copy over only those blocks that have changed since the copy began. The blocks not copied are still available on the source volume, so there is no need to duplicate this data.
Archiving and Space Management: Data can be moved out of production databases and stored elsewhere on disk or tape. Enough XML metadata is carried along so that there is no loss in the fine detail of what each row and column represent.
Data Deduplication: The idea is simple. Find large chunks of data that contain the same exact information as an existing chunk already stored, and merely set a pointer to avoid storing the duplicate copy. This can be done in-line as data is written, or as a post-process task when things are otherwise slow and idle.
When data deduplication first came out, some lawyers were concerned that this was a "lossy" approach, that somehow documents were coming back without some of their original contents. How else can you explain storing 25PB of data on only 1PB of disk?
(In some countries, companies must retain data in their original file formats, as there is concern that converting business documents to PDF or HTML would lose some critical "metadata" information such as modificatoin dates, authorship information, underlying formulae, and so on.)
Well, the concern applies only to those data deduplication methods that calculate a hash code or fingerprint, such as EMC Centera or EMC Data Domain. If the hash code of new incoming data matches the hash code of existing data, then the new data is discarded and assumed to be identical. This is rare, and I have only read of a few occurrences of unique data being discarded in the past five years. To ensure full integrity, IBM ProtecTIER data deduplication solution and IBM N series disk systems chose instead to do full byte-for-byte comparisons.
Compression: There are both lossy and lossless compression techniques. The lossless Lempel-Ziv algorithm is the basis for LTO-DC algorithm used in IBM's Linear Tape Open [LTO] tape drives, the Streaming Lossless Data Compression (SLDC) algorithm used in IBM's [Enterprise-class TS1130] tape drives, and the Adaptive Lossless Data Compression (ALDC) used by the IBM Information Archive for its disk pool collections.
Last month, IBM announced that it was [acquiring Storwize. It's Random Access Compression Engine (RACE) is also a lossless compression algorithm based on Lempel-Ziv. As servers write files, Storwize compresses those files and passes them on to the destination NAS device. When files are read back, Storwize retrieves and decompresses the data back to its original form.
As with tape, the savings from compression can vary, typically from 20 to 80 percent. In other words, 10TB of primary data could take up from 2TB to 8TB of physical space. To estimate what savings you might achieve for your mix of data types, try out the free [Storwize Predictive Modeling Tool].
So why am I making a distinction on terminology here?
Data reduction is already a well-known concept among specific industries, like High-Performance Computing (HPC) and Business Analytics. IBM has the largest marketshare in supercomputers that do data reduction for all kinds of use cases, for scientific research, weather prediction, financial projections, and decision support systems. IBM has also recently acquired a lot of companies related to Business Analytics, such as Cognos, SPSS, CoreMetrics and Unica Corp. These use data reduction on large amounts of business and marketing data to help drive new sources of revenues, provide insight for new products and services, create more focused advertising campaigns, and help understand the marketplace better.
There are certainly enough methods of reducing the quantity of storage capacity consumed, like thin provisioning, data deduplication and compression, to warrant an "umbrella term" that refers to all of them generically. I would prefer we do not "overload" the existing phrase "data reduction" but rather come up with a new phrase, such as "storage efficiency" or "capacity optimization" to refer to this category of features.
IBM is certainly quite involved in both data reduction as well as storage efficiency. If any of my readers can suggest a better phrase, please comment below.
My series last week on IBM Watson (which you can read [here], [here], [here], and [here]) brought attention to IBM's Scale-Out Network Attached Storage [SONAS]. IBM Watson used a customized version of SONAS technology for its internal storage, and like most of the components of IBM Watson, IBM SONAS is commercially available as a stand-alone product.
Like many IBM products, SONAS has gone through various name changes. First introduced by Linda Sanford at an IBM SHARE conference in 2000 under the IBM Research codename Storage Tank, it was then delivered as a software-only offering SAN File System, then as a services offering Scale-out File Services (SoFS), and now as an integrated system appliance, SONAS, in IBM's Cloud Services and Systems portfolio.
If you are not familiar with SONAS, here are a few of my previous posts that go into more detail:
This week, IBM announces that SONAS has set a world record benchmark for performance, [a whopping 403,326 IOPS for a single file system]. The results are based on comparisons of publicly available information from Standard Performance Evaluation Corporation [SPEC], a prominent performance standardization organization with more than 60 member companies. SPEC publishes hundreds of different performance results each quarter covering a wide range of system performance disciplines (CPU, memory, power, and many more). SPECsfs2008_nfs.v3 is the industry-standard benchmark for NAS systems using the NFS protocol.
(Disclaimer: Your mileage may vary. As with any performance benchmark, the SPECsfs benchmark does not replicate any single workload or particular application. Rather, it encapsulates scores of typical activities on a NAS storage system. SPECsfs is based on a compilation of workload data submitted to the SPEC organization, aggregated from tens of thousands of fileservers, using a wide variety of environments and applications. As a result, it is comprised of typical workloads and with typical proportions of data and metadata use as seen in real production environments.)
The configuration tested involves SONAS Release 1.2 on 10 Interface Nodes and 8 Storage Pods, resulting a single file system over 900TB usable capacity.
10 Interface Nodes; each with:
Maximum 144 GB of memory
One active 10GbE port
8 Storage Pods; each with:
2 Storage nodes and 240 drives
Drive type: 15K RPM SAS hard drives
Data Protection using RAID-5 (8+P) ranks
Six spare drives per Storage Pod
IBM wanted a realistic "no compromises" configuration to be tested, by choosing:
Regular 15K RPM SAS drives, rather than a silly configuration full of super-expensive Solid State Drives (SSD) to plump up the results.
Moderate size, typical of what clients are asking for today. The Goldilocks rule applies. This SONAS is not a small configuration under 100TB, and nowhere close to the maximum supported configuration of 7,200 disks across 30 Interface Nodes and 30 Storage Pods.
Single file system, often referred to as a global name space, rather than using an aggregate of smaller file systems added together that would be more complicated to manage. Having multiple file systems often requires changes to applications to take advantage of the aggregate peformance. It is also more difficult to load-balance your performance and capacity across multiple file systems. Of course, SONAS can support up to 256 separate file systems if you have a business need for this complexity.
The results are stunning. IBM SONAS handled three times more workload for a single file system than the next leading contender. All of the major players are there as well, including NetApp, EMC and HP.
It's Tuesday, and you know what that means? IBM Announcements! This week I am in beautiful Orlando, Florida for the [IBM Systems Technical University] conference.
This week, IBM announced its latest tape offerings for the seventh generation of Linear Tape Open (LTO-7), providing huge gains in performance and capacity.
For capacity, the new LTO-7 cartridges can hold up to 6TB native capacity, or 15TB effective capacity with 2.5x compression that for typical data. That is 2.4x larger than the 2.5TB catridges available with LTO-6. Performance is also nearly doubled, with a native throughput of 315 MB/sec, or effective 780 MB/sec effective capacity with 2.5x compression. The LTO consortium, of which IBM is a founding member, has published the roadmap for LTO generations to LTO-8, LTO-9 and LTO-10.
IBM will offer both half-height and full-height LTO-7 tape drives. All the features you love from LTO-6 like WORM, partitioning and Encryption carry forward. These drives will be supported on a variety of distributed operating systems, including Linux on z System mainframes, and the IBM i platform on POWER Systems.
The Linear Tape File System (LTFS) can be used to treat LTO-7 cartridges in much the same way as Compact Discs or USB memory sticks, allowing one person to create conent on an LTO-7 tape cartridge, and pass that cartridge to the next employee, or to another company. LTFS is also the basis for IBM Spectrum Archive that allows tape data to be part of a global namespace with IBM Spectrum Scale.
LTO-7 will be supported on the TS2900 auto-loader, as well as all of IBM's tape libraries: TS3100, TS3200, TS3310, TS3500 and TS4500. You can connect up to 15 TS3500 tape libraries together with shuttle connectors, for a maximum capacity of 2,700 drives serving 300,000 cartridges, for a maximum capacity of 1.8 Exabytes of data in a single system environment.
In addition to LTO-7 support, the IBM TS4500 tape library was also enchanced. You can now grow it up to 18 frames, and have up to 128 drives serving 23,170 cartridges, for a maximum capacity of 139 PB of data. You can now also intermix LTO and 3592 frames in the same TS4500 tape library.
For comptability, LTO-7 drives can read existing LTO-5 and LTO-6 tape cartridges, and can write to LTO-6 media, to help clients with transition.
Continuing on the [IBM Storage Launch of February 9], John Sing has offered to write the following guest post about the [announcement] of IBM Scale Out Network Attached Storage [IBM SONAS]. John and I have known each other for a while, traveled the world to work with clients and speak at conferences. He is an Executive IT Consultant on the SONAS team.
Guest Post written by John Sing, IBM San Jose, California
What is IBM SONAS? It’s many things, so let’s start with this list:
It’s IBM’s delivery of a productized, pre-packaged Scale Out NAS global virtual file server, delivered in a easy-to-use appliance
IBM’s solution for large enterprise file-based storage requirements, where massive scale in capacity and extreme performance is required, especially for today’s modern analytics-based Competitive Advantage IT applications
Scales to many petabytes of usable storage and billions of files in a single global namespace
Provides integrated central management, central deployment of petabyte levels of storage
Modular commercial-off-the-shelf [COTS] building blocks. I/O, storage, network capacity scale independently of each other. Up to 30 interface nodes and 60 storage nodes, in an IBM General Parallel File System [GPFS]-based cluster. Each 10Gb CEE interface node port is capable of streaming at 900 MB/sec
Files are written in block-sized chunks, striped over as many multiple disk drives in parallel – aggregating throughput on a massive scale (both read and write), as well as providing auto-tuning, auto-balancing
Functionality delivered via one program product, IBM SONAS Software, which provides all of above functions, along with clustered CIFS, NFS v2/v3 with session auto-failover, FTP, high availability, and more
IBM SONAS makes automated tiered storage achievable and realistic at petabyte levels:
Integrated high performance parallel scan engine capable of identifying files at over 10 million files per minute per node
Integrated parallel data movement engine to physically relocate the data within tiered storage
And we’re just scratching the surface. IBM has plans to deploy additional protocols, storage hardware options, and software features.
However, the real question of interest should be, “who really needs that much storage capacity and throughput horsepower?”
The answer may surprise you. IMHO, the answer is: almost any modern enterprise that intends to stay competitive. Hmmm…… Consider this: the reason that IT exists today is no longer to simply save cost (that may have been true 10 years ago). Everyone is reducing cost… but how much competitive advantage is purchased through “let’s cut our IT budget by 10% this year”?
Notice that in today’s world, there are (many) bright people out there, changing our world every day through New Intelligence Competitive Advantage analytics-based IT applications such as real time GPS traffic data, real time energy monitoring and redirection, real time video feed with analytics, text analytics, entity analytics, real time stream computing, image recognition applications, HDTV video on demand, etc. Think of how GPS industry, cell phone / Twitter / Facebook, iPhone and iPad applications, as examples, are creating whole new industries and markets almost overnight.
Then start asking yourself, “What's behind these Competitive Advantage IT applications – as they are the ones that are driving all my storage growth? Why do they need so much storage? What do those applications mean for my storage requirements?”
To be “real-time”, long-held IT paradigms are being broken every day. Things like “data proximity”: we can no longer can extract terabytes of data from production databases and load them to a data warehouse – where’s the “real-time” in that? Instead, today’s modern analytics-based applications demand:
Multiple processes and servers (sometimes numbering in the 100s) simultaneously ….
Running against hundreds of terabytes of data of live production data, streaming in from expanding number of smarter sensors, input devices, users
Producing digital image-intensive results that must be programatically sent to an ever increasing number of mobile devices in geographically dispersed storage
Requiring parallel performance levels, that used to be the domain only of High Performance Computing (HPC)
This is a major paradigm shift in storage – and that is the solution and storage capabilities that IBM SONAS is designed to address. And of course, you should be able to save significant cost through the SONAS global virtual file server consolidation and virtualization as well.
Certainly, this topic warrants more discussion. If you found it interesting, contact me, your local IBM Business Partner or IBM Storage rep to discuss Competitive Advantage IT applications and SONAS further.
Happy Winter Solstice everyone! The Mayan calendar flipped over yesterday, and everything continued as normal.
The next date to watch out for is ... drumroll please ... April 8, 2014. This is the date Microsoft has decided to [drop support for Windows XP].
While many large corporations are actively planning to get off Windows XP, there are still many homes and individuals that are running on this platform.
When [Windows XP] was introduced in 2001, it could support systems with as little as 64MB of RAM. Nowadays, the latest versions of Windows now requires a minimum of 1GB for 32-bit systems, with 2GB or 3GB recommended.
That leaves Windows XP users on older hardware few choices:
Continue to run Windows XP, but without support (and hope for the best)
Upgrade their hardware with more RAM (and possibly more disk space) needed to run a newer level of Windows
Install a different operating system like Linux
Put the hardware in the recycle bin, and buy a new computer
Here is a personal example. A long time ago, I gave my sister a Thinkpad R31 laptop so that she could work from home. When she got a newer one, she passed this down to her daughter for doing homework. When my neice got a newer one, she passed this old laptop to her grandma.
Grandma is fairly happy with her modern PC running Windows XP. She plays all kinds of games, scans photographs, sends emails, listens to music on iTunes, and even uses Skype to talk to relatives. Her problem is that this PC is located upstairs, in her bedroom, and she wanted something portable that she could play music downstairs when she is playing cards with her friends.
"Why not use the laptop you have?" I asked. Her response: "It runs very slow. Perhaps it has a virus. Can you fix that?" I was up for the challenge, so I agreed.
(The Challenge: Update the Thinkpad R31 so that grandma can simply turn it on, launch iTunes or similar application, and just press a "play" button to listen to her music. It will be plugged in to an electrical outlet wherever she takes it, and she already has her collection of MP3 music files. My hope is to have something that is (a) simple to use, (b) starts up quickly, and (c) will not require a lot of on-going maintenance issues.)
Here are the relevant specifications of the Thinkpad R31 laptop:
The system was pre-installed with Windows XP, but was terribly down-level. I updated to Windows XP SP3 level, downloaded the latest anti-virus signatures, and installed iTunes. A full scan found no viruses. All this software takes up 14GB, leaving less than 6GB for MP3 music files.
The time it took from hitting the "Power-on" button to hearing the first note of music was over 14 minutes! Unacceptable!
If you can suggest what my next steps should be, please comment below or send me an email!
(Note: The following paragraphs have been updated to clarify the performance tests involved.)
This time, IBM breaks the 1 million IOPS barrier, achieved by running a test workload consisting of a 70/30 mix of random 4K requests. That is 70 percent reads, 30 percent writes, with 4KB blocks. The throughput achieved was 3.5x times that obtained by running the identical workload on the fastest IBM storage system today (IBM System Storage SAN Volume Controller 4.3),
and an estimated EIGHT* times the performance of EMC DMX. With an average response time under 1 millisecond, this solution would be ideal for online transaction processing (OLTP) such as financial recordings or airline reservations.
(*)Note: EMC has not yet published ANY benchmarks of their EMC DMX box with SSD enterprise flash drives (EFD). However, I believe that the performance bottleneck is in their controller and not the back-end SSD or FC HDD media, so I have givenEMC the benefit of the doubt and estimated that their latest EMC DMX4 is as fast as an[IBMDS8300 Turbo] with Fibre Channel drives. If or when EMC publishes benchmarks, the marketplace can make more accurate comparisons. Your mileage may vary.
IBM used 4 TB of Solid State Disk (SSD) behind its IBM SAN Volume Controller (SVC) technology to achieve this amazing result. Not only does this represent a significantly smaller footprint, but it uses only 55 percent of the power and cooling.
The SSD drives are made by [Fusion IO] and are different than those used by EMC made by STEC.
The SVC addresses the one key problem clients face today with competitive disk systems that support SSD enterprise flash drives: choosing what data to park on those expensive drives? How do you decide which LUNs, which databases, or which files should be permanently resident on SSD? With SVC's industry-leading storage virtualization capability, you are not forced to decide. You can move data into SSD and back out again non-disruptively, as needed to meet performance requirements. This could be handy for quarter-end or year-end processing, for example.
Well it's Tuesday again, and you know what that means.. IBM announcements! Today, IBM announces that next Monday marks the 60th anniversary of first commercial digital tape storage system! I am on the East coast this week visiting clients, but plan to be back in Tucson in time for the cake and fireworks next Monday.
1925 - masking tape (which 3M sold under its newly announced Scotch® brand)
1930 - clear cellulose-based tape (today, when people say Scotch tape, they usually are referring to the cellulose version)
1935 - Allgemeine Elektrizitatsgesellschaft (AEG) presents Magnetophon K1, audio recording on analog tape
1942 - Duct tape
1947 - Bing Crosby adopts audio recording for his radio program. This eliminated him doing the same program live twice per day, perhaps the first example of using technology for "deduplication".
According to the IBM Archives the [IBM 726 tape drive was formally announced May 21, 1952]. It was the size of a refrigerator, and the tape reel was the size of a large pizza. The next time you pull a frozen pizza from your fridge, you can remember this month's celebration!
When I first joined IBM in 1986, there were three kinds of IBM tape. The round reel called 3420, and the square cartridge called 3480, and the tubes that contained a wide swath of tape stored in honeycomb shelves called the [IBM 3850 Mass Storage System].
My first job at IBM was to work on DFHSM, which was specifically started in 1977 to manage the IBM 3850, and later renamed to the DFSMShsm component of the DFSMS element of the z/OS operating system. This software was instrumental in keeping disk and tape at high 80-95 percent utilization rates on mainframe servers.
While visiting a client in Detroit, the client loved their StorageTek tape automation silo, but didn't care for the StorageTek drives inside were incompatible with IBM formats. They wanted to put IBM drives into the StorageTek silos. I agreed it was a good idea, and brought this back to the attention of development. In a contentious meeting with management and engineers, I presented this feedback from the client.
Everyone in the room said IBM couldn't do that. I asked "Why not?" The software engineers I spoke to already said they could support it. With StorageTek at the brink of Chapter 11 bankruptcy, I argued that IBM drives in their tape automation would ease the transition of our mainframe customers to an all-IBM environment.
Was the reason related to business/legal concerns, or was their a hardware issue? It turned out to be a little of both. On the business side, IBM had to agree to work with StorageTek on service and support to its mutual clients in mixed environments. On the technical side, the drive had to be tilted 12 degrees to line up with the robotic hand. A few years later, the IBM silo-compatible 3592 drive was commercially available.
Rather than put StorageTek completely out of business, it had the opposite effect. Now that IBM drives can be put in StorageTek libraries, everyone wanted one, basically bringing StorageTek back to life. This forced IBM to offer its own tape automation libraries.
In 1993, I filed my first patent. It was for the RECYCLE function in DFHSM to consolidate valid data from partial tapes to fresh new tapes. Before my patent, the RECYCLE function selected tapes alphabetically, by volume serial (VOLSER). My patent evaluated all tapes based on how full they were, and sorted them least-full to most-full, to maximize the return of cartridges.
Different tape cartridges can hold different amounts of data, especially with different formats on the same media type, with or without compression, so calculating the percentage full turned out to be a tricky algorithm that continues to be used in mainframe environments today.
The patent was popular for cross-licensing, and IBM has since filed additional patents for this invention in other countries to further increase its license revenue for intellectual property.
In 1997, IBM launched the IBM 3494 Virtual Tape Server (VTS), the first virtual tape storage device, blending disk and tape to optimal effect. This was based off the IBM 3850 Mass Storage Systems, which was the first virtual disk system, that used 3380 disk and tape to emulate the older 3350 disk systems.
In the VTS, tape volume images would be emulated as files on a disk system, then later moved to physical tape. We would call the disk the "Tape Volume Cache", and use caching algorithms to decide how long to keep data in cache, versus destage to tape. However, there were only a few tape drives, and sometimes when the VTS was busy, there were no tape drives available to destage the older images, and the cache would fill up.
I had already solved this problem in DFHSM, with a function called pre-migration. The idea was to pre-emptively copy data to tape, but leave it also on disk, so that when it needed to be destaged, all we had to do was delete the disk copy and activate the tape copy. We patented using this idea for the VTS, and it is still used in the successor models of IBM Sysem Storage TS7740 virtual tape libraries today.
Today, tape continues to be the least expensive storage medium, about 15 to 25 times less expensive, dollar-per-GB, than disk technologies. A dollar of today's LTO-5 tape can hold 22 days worth of MP3 music at 192 Kbps recording. A full TS1140 tape cartridge can hold 2 million copies of the book "War and Peace".
(If you have not read the book, Woody Allen took a speed reading course and read the entire novel in just 20 minutes. He summed up the novel in three words: "It involves Russia." By comparison, in the same 20 minutes, at 650MB/sec, the TS1140 drive can read this novel over and over 390,000 times.)
If you have your own "war stories" about tape, I would love to hear them, please consider posting a comment below.
Well, it's Tuesday, and that means IBM announcements!
IBM kicks EMC in the teeth with the announcement of System Storage Easy Tier, a new feature available at no additional charge on the DS8700 with the R5.1 level microcode. Barry Whyte introduces the concept in his [post this morning]. I will use SLAM (sub-LUN automatic movement) to refer generically to IBM Easy Tier and EMC FAST v2. EMC has yet to deliver FAST v2, and given that they just recently got full-LUN FAST v1 working a few months ago, it might be next year before you see EMC sub-LUN FAST v2.
Here are the key features of Easy Tier on the DS8700:
Sub-LUN Automatic Movement
IBM made it really easy to implement this on the DS8700. Today, you have "extent pools" that can be either SSD-only or HDD-only. With this new announcement, we introduce "mixed" SSD+HDD extent pools. The hottest extents are moved to SSD, and cooler extents are moved down to HDD. The support applies to both Fixed block architecture (FBA) LUNs as well as Count-Key-Data (CKD) volumes. In other words, an individual LUN or CKD volume can have some of its 1GB extents on SSD and other extents on FC or SATA disk.
Entire-LUN Manual Relocation
Entire-LUN Manual Relocation (ELMR, pronounced "Elmer"?) is similar to what EMC offers now with FAST v1. With this feature, you can now relocate an entire LUN non-disruptively from any extent pool to any other extent pool. You can relocate LUNs from an SSD-only or HDD-only pool over to a new Easy Tier-managed "mixed" pool, or take a LUN out of Easy Tier management by moving it to an SSD-only or HDD-only pool. Of course, this support also applies to both Fixed block architecture (FBA) LUNs as well as Count-Key-Data (CKD) volumes.
This feature also can be used to relocate LUNs and CKD volumes from FC to SATA pools, from RAID-10 to RAID-5 pools, and so on.
What if you already have SSD-only and HDD-only pools and want to use Easy Tier? You can now merge pools to create a "mixed" pool.
Before this announcement, you had to buy 16 solid-state drives at a time, called Mega-packs. Now, you can choose to buy just 8 SSD at a time, called Mini-packs. It turns out that just moving as little as 10 percent of your data from Fibre Channel disk over to Solid-State with Easy Tier can result in up to 300 to 400 percent performance improvement. IBM plans to publish formal SPC-1 benchmark results using Easy Tier-managed mixed extent pool in a few weeks.
Storage Tier Advisor Tool (STAT)
Don't have SSD yet, or not sure how awesome Easy Tier will be for your data center? The IBM Storage Tier Advisor Tool will analyze your extents and estimate how much benefit you will derive if you implement Easy Tier with various amounts of SSD. Those clients with R5.1 microcode on their DS8700 can download from the [DS8700 FTP site].
Wrapping up my series on a [Laptop for Grandma], I finally have something that I think meets all of my requirements! Special thanks to Guidomar and the rest of my readers who sent in suggestions!
I could have called this series "The Good, the Bad, and the Ugly". The [Cloud-oriented choices] weren't bad per se, but expected persistent Internet connection. The [Low-RAM choices] were not ugly per se, but had limited application options. The ones below were good, in that they helped me decide what would be just right for grandma.
Linux Mint 9
One of my readers, Guidomar, suggested Linux Mint Xfce. At LinuxFest Northwest 2012, Bryan Lunduke indicated that [Linux Mint] is the fastest growing Linux in popularity. You can watch his 43-minute presentation of [Why Linux Sucks!] on YouTube.
The latest version is Mint 14, but that has grown so big it has to be installed on a DVD, as it will no longer fit on a 700MB CD-ROM. Since I don't have a DVD drive on this Thinkpad R31, I dropped down to the latest Gnome edition that did fit on a LiveCD, which was Mint 9.
(In retrospect, I could have used the [PLoP Boot Manager CD], and installed the latest Linux Mint 14 from USB memory stick! My concern was that if a distribution didn't fit on a CD-ROM, it was expecting a more modern computer overall, and thus would probably require more than 384MB or RAM as well.)
Linux Mint is actually a variant of Ubuntu, which means that it can tap into the thousands of applications already available. Mint 9 is based on Ubuntu 10.04 LTS.
One of the nice features of Linux Mint is that there are versions with full [Codecs] installed. A codec is a coder/decoder software routine that can convert a digital data stream or signal, such as for audio or video data. Many formats are proprietary, so codecs are generally not open source, and often not included in most Linux distros. They can be installed manually by the Linux administrator. Windows and Mac OS are commercially sold and don't have this problem, as Microsoft and Apple take care of all the licensing issues behind the scenes.
The installation went smooth. It would have gladly set up a dual-boot with Windows for me, but instead I opted to wipe the disk clean and install fresh for each Linux distribution I tried.
Running it was a different matter. The screen would go black and crash. There just wasn't enough memory.
Since [Peppermint OS] was partially based on Lubuntu, I thought I would give [Lubuntu 12.04] a try. The difference is that Peppermint OS is based on Xfce (as is Xubuntu), but Lubuntu claims to have a smaller memory footprint using Lightweight X11 Desktop Environment (LXDE). This version claims to run in 384MB, which is what I have on grandma's Thinkpad R31.
There are two installers. The main installer requires more than 512MB to run, so I used the alternate text-based Installer-only CD, which needs only 192MB.
The LXDE GUI is simple and straightforward. As with Peppermint OS, I did have to install the Codec plugins. However, the time-to-first-note was less than two minutes, so we can count this as a success!
Linux Mint 12 LXDE edition
Circling back to Linux Mint, I realized that my problem up above was chosing the wrong edition. Apparently, Linux Mint comes in various editions, the main edition I had selected was based on Gnome which requires at least 512MB of RAM.
Other editions are based on KDE, xFCE and LXDE. Linux Mint 9 LXDE requires only 192MB of RAM, and the newer Linux Mint 12 LXDE requires only 256MB. I choose the latter, and the install went pretty much the same as Mint and Lubuntu above.
The music player that comes pre-installed is called [Exaile], which supports playlists, audio CDs, and a variety of other modern features, so no reason to install Rhythmbox or anything else. Grandma can even rip her existing audio CDs to import her music into MP3 format. Time-to-first-note was about two minutes.
The best part: the OS only takes up about 4GB of disk, leaving about 15GB for MP3 music files!
Lubuntu and Linux Mint LXDE were similar, but I decided to go with the latter because I like that they do not force version upgrades. This is a philosophical difference. Ubuntu likes to keep everyone on the latest supported releases, so will often remind you its time to upgrade. Linux Mint prefers to take an if-it-aint-broke-don't-fix-it approach that will be less on-going maintenance for me.
A few finishing touches to make the system complete:
A nice wallpaper from [InterfaceLift]. This website has high-res photography that are just stunning.
Power management with screen-saver settings to a nice pink background with white snowflakes falling.
A small collection of her MP3 music pre-loaded so that she would have something to listen to while she learns how to rip CDs and copy over the rest of her music.
Icons on the main desktop for Exaile, My Computer, Home Directory, and the Welcome Screen.
Larger Font size, to make it easier to read.
Update settings that only look for levels "1" and "2". There are five levels, but "1" and "2" are considered the safest, tested versions. Also, an update is only done if it does not involve installing or removing other packages. This should offer some added stability.
I considered installing [ClamAV] for anti-virus protection, but since this laptop will not be connected to the Internet, I decided not to burn up CPU cycles. I also considered installing [Team Viewer] which would allow me remote access to her system if anything should every fail. However, since she does not have Wi-Fi at home, and lives only a few minutes across town, I decided to leave this off.
Once again, I want to thank all of my readers for their suggestions! I learned quite a lot on this journey, and am glad that I have something that I am proud to present to grandma: boots quickly enough, simple to use, and does not require on-going maintenance!
In my post yesterday [Spreading out the Re-Replication process], fellow blogger BarryB [aka The Storage Anarchist]raises some interesting points and questions in the comments section about the new IBM XIV Nextra architecture.I answer these below not just for the benefit of my friends at EMC, but also for my own colleagues within IBM,IBM Business Partners, Analysts and clients that might have similar questions.
If RAID 5/6 makes sense on every other platform, why not so on the Web 2.0 platform?
Your attempt to justify the expense of Mirrored vs. RAID 5 makes no sense to me. Buying two drives for every one drive's worth of usable capacity is expensive, even with SATA drives. Isn't that why you offer RAID 5 and RAID 6 on the storage arrays that you sell with SATA drives?
And if RAID 5/6 makes sense on every other platform, why not so on the (extremely cost-sensitive) Web 2.0 platform? Is faster rebuild really worth the cost of 40+% more spindles? Or is the overhead of RAID 6 really too much for those low-cost commodity servers to handle.
Let's take a look at various disk configurations, for example 3TB on 750GB SATA drives:
JBOD: 4 drives
JBOD here is industry slang for "Just a Bunch of Disks" and was invented as the term for "non-RAID".Each drive would be accessible independently, at native single-drive speed, with no data protection. Puttingfour drives in a single cabinet like this provides simplicity and convenience only over four separate drivesin their own enclosures.
RAID-10: 8 drives
RAID-10 is a combination of RAID-1 (mirroring) and RAID-0 (striping). In a 4x2 configuration, data is striped across disks 1-4,then these are mirrored across to disks 5-8. You get performance improvement and protection against a singledrive failure.
RAID-5: 5 drives
This would be a 4+P configuration, where there would be four drives' worth of data scattered across fivedrives. This gives you almost the same performance improvement as RAID-10, similar protection againstsingle drive failure, but with fewer drives per usable TB capacity.
RAID-6: 6 drives
This would be a 4+2P configuration, where the first P represents linear parity, and the second represents a diagonal parity. Similar in performance improvement as RAID-5, but protects against single and double drive failures, and still better than RAID-10 in terms of drives per TB usable capacity.
For all the RAID configurations, rebuild would require a spare drive, but often spares are shared among multiple RAID ranks, not dedicated to a single rank. To this end, you often have to have several spares per I/O loop, and a different set of spares for each kind of speed and capacity. If you had a mix of 15K/73GB, 10K/146GB, and 7200/500GB drives, then you would have three sets of spares to match.
In contrast, IBM XIV's innovative RAID-X approach doesn't requireany spare drives, just spare capacity on existing drives being used to hold data. The objects can be mirroredbetween any two types of drives, so no need to match one with another.
All of these RAID levels represent some trade-off between cost, protection and performance, and IBM offers each of theseon various disk systems platforms. Calculating parity is more complicated than just mirrored copies, but this can be done with specialized chips in cache memory to minimize performance impact.IBM generally recommends RAID-5 for high-performance FC disk, and RAID-6 for slower, large capacity SATA disk.
However, the questionassumes that the drive cost is a large portion of the overall "disk system" cost. It isn't. For example,Jon Toigo discusses the cost of EMC's new AX4 disk system in his post [National Storage Rip-Off Day]:
EMC is releasing its low end Clariion AX4 SAS/SATA array with 3TB capacity for $8600. It ships with four 750GB SATA drives (which you and I could buy at list for $239 per unit). So, if the disk drives cost $956 (presumably far less for EMC), that means buyers of the EMC wares are paying about $7700 for a tin case, a controller/backplane, and a 4Gbps iSCSI or FC connector. Hmm.
Dell is offering EMC’s AX4-5 with same configuration for $13,000 adding a 24/7 warranty.
(Note: I checked these numbers. $8599 is the list price that EMC has on its own website. External 750GB drivesavailable at my local Circuit City ranged from $189 to $329 list price. I could not find anything on Dell'sown website, but found [The Register] to confirm the $13,000 with 24x7 warranty figure.)
Disk capacity is a shrinking portion of the total cost of ownership (TCO). In addition to capacity, you are paying forcache, microcode and electronics of the system itself, along with software and services that are included in the mix,and your own storage administrators to deal with configuration and management. For more on this, see [XIV storage - Low Total Cost of Ownership].
EMC Centera has been doing this exact type of blob striping and protection since 2002
As I've noted before, there's nothing "magic" about it - Centera has been employing the same type of object-level replication for years. Only EMC's engineers have figured out how to do RAID protection instead of mirroring to keep the hardware costs low while not sacrificing availability.
I agree that IBM XIV was not the first to do an object-level architecture, but it was one of the first to apply object-level technologies to the particular "use case" and "intended workload" of Web 2.0 applications.
RAID-5 based EMC Centera was designed insteadto hold fixed-content data that needed to be protected for a specific period of time, such as to meet government regulatory compliance requirements. This is data that you most likelywill never look at again unless you are hit with a lawsuit or investigation. For this reason, it is important to get it on the cheapest storage configuration as possible. Before EMC Centera, customers stored this data on WORM tape and optical media, so EMC came up with a disk-only alternative offering.IBM System Storage DR550 offers disk-level access for themost recent archives, with the ability to migrate to much less expensive tape for the long term retention. The end result is that storing on a blended disk-plus-tape solution can help reduce the cost by a factor of 5x to 7x, making RAID level discussion meaningless in this environment. For moreon this, see my post [OptimizingData Retention and Archiving].
While both the Centera and DR550 are based on SATA, neither are designed for Web 2.0 platforms.When EMC comes out with their own "me, too" version, they will probably make a similar argument.
IBM XIV Nextra is not a DS8000 replacement
Nextra is anything but Enterprise-class storage, much less a DS8000 replacement. How silly of all those folks to suggest such a thing.
I did searches on the Web and could not find anybody, other than EMC employees, who suggested that IBM XIV Nextra architecture represented a replacement for IBM System Storage DS8000. The IBM XIV press release does not mentionor imply this, and certainly nobody I know at IBM has suggested this.
The DS8000 is designed for a different "use case" andset of "intended workloads" than what the IBM XIV was designed for. The DS8000 is the most popular disk systemfor our IBM System z mainframe platform, for activities like Online Transaction Processing (OLTP) and large databases, supporting ESCON and FICON attachment to high-speed 15K RPM FC drives. Web 2.0 customers that might chooseIBM XIV Nextra for their digital content might run their financial operations or metadata search indexes on DS8000.Different storage for different purposes.
As for the opinion that this is not "enterprise class", there are a variety of definitions that refer to this phrase.Some analysts look at "price band" of units that cost over $300,000 US dollars. Other analysts define this as beingattachable to mainframe servers via ESCON or FICON. Others use the term to refer to five-nines reliability, havingless than 5 minutes downtime per year. In this regard, based on the past two years experience at 40 customer locations,I would argue that it meets this last definition, with non-disruptive upgrades, microcode updates and hot-swappable components.
By comparison, when EMC introduced its object-level Centera architecture, nobody suggested it was the replacement for their Symmetrix or CLARiiON devices. Was it supposed to be?
Given drive growth rates have slowed, improving utilization is mandatory to keep up with 60-70 percent CAGR
Look around you, Tony- all of your competitors are implementing thin provisioning specifically to drive physical utilization upwards towards 60-80%, and that's on top of RAID 5/RAID 6 storage and not RAID 1. Given that disk drive growth rates and $/GB cost savings have slowed significantly, improving utilization is mandatory just to keep up with the 60-70% CAGR of information growth.
Disk drive capacities have slowed for FC disk because much of the attention and investment has been re-directed to ATA technology. Dollar-per-GB price reduction is slowing for disks in general, as researchers are hitting physicallimitations to the amount of bits they can pack per square inch of disk media, and is now around 25 percent per year.The 60-70 percent Compound Annual Growth Rate (CAGR) is real, and can be even growing faster for Web 2.0providers. While hardware costs drop, the big ticket items to watch will be software, services and storage administrator labor costs.
To this end, IBM XIV Nextra offers thin provisioning and differential space-efficient snapshots. It is designed for 60-90 percent utilization, and can be expanded to larger capacities non-disruptively in a very scalable manner.