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 )
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Well, it's Tuesday again, and we had several announcements this month, so here is a quick recap.We had some things announce May 13, and then some more announcements today, but since I was busywith conferences, will combine them into one post for the entire month of May 2008.
This time, I thought I would go "audio" with a recording from Charlie Andrews, IBM director ofproduct marketing for IBM System Storage:
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.
Today was a special day! IBM launched the world's first "Global Archive Solutions Center" in Guadalajara, Mexico.We had a formal "ribbon cutting", shown here were the following dignitaries (from left to right):
Eugenio Godard, IBM Guadalajara site level executive
Andy Monshaw, IBM General Manager of IBM System Storage
Cindy Grossman, IBM VP of Tape and Archive solutions
Luis Guillermo Martinez Mora, Secretary of economic development for the state of Jalisco, Mexico
José Décurnex, IBM General Manager for the country of Mexico
In the morning, we had a series of speeches from Cindy Grossman, Andy Monshaw, Eugenio Godard, and Federico Lepe (technology advisor for the governor for the state of Jalisco, Mexico).
While the hordes of press journalists, analysts and clients were taking the lab tour, we took a snap of thefront entrance. The day was packed with activity.
After the lab tour, IBMers Clod Barrera and Craig Butler presented to the analysts.
Cindy Grossman explained why IBM created a solutions center specific to archive solutions, and why wechose Guadalajara for its location.
I presented the pains and challenges companies are facing, and why they should partner with IBM forarchive solutions to address those requirements
Harley Puckett and I split the group. Harley is my colleague at the IBM Tucson ExecutiveBriefing Center who was the focal point for the various aspects of launching for the past eight months.He presented and moderated the presentations and demos to a collection of prospective clients.
That's me on the left, with Harley on the right.
I moderated a series of speakers to press and analysts. These included:
Mark LaBelle, Spectrum Health server and storage manager, and Steve Lawrence, Spectrum Health image solutions architect, presented their success story using IBM Grid Medical Archive Solution (GMAS). [Spectrum Health] manages seven hospitals and 130 service locations in Michigan, USA.
Mark Uren, ABSA technical architect, presented their success story working with IBM in deploying their Information Lifecycle Management (ILM) which includes Enterprise Content Management and archiving. Mark flew in all the way from Johannesburg, South Africa. [ABSA] is the financial services subsidiary of Barclay's serving theAfrican continent.
Jeffrey Beallor, president of [Global Data Vaulting], presented his success story as both a client and IBM Business Partner, offering backup and archiving solutions through "Software as a Service" (SaaS) business model. GlobalData Vaulting has its data centers in Canada, but provides services to clients worldwide.
We had a Q&A panel with the company representatives from Spectrum Health, ABSA, and Global Data Vaulting; followed by a Q&A panel with the collection of IBM executives to take questions from the press and analysts.Special thanks to Cyntia, Daniela, Carlos, Raul and Salvador for their help in making this a successful event!
(all three photos on this blog post taken by Mauricio, a professional photographer IBM hired for this event)
Continuing this week's theme on "best of breed", some questions arise: How is this calculated or determined?How is one storage solution "better" than another? Which attributes weigh more heavily in the decision?
Some attributes are directly measurable, like storage performance. For this, gather up a list ofall the storage products you are interested in, go to the [Storage Performance Council website],determine whether SPC-1 or SPC-2more closely matches your application workload, and then choose the best product fromthe benchmarks, discarding any vendors that don't bother to have benchmarks posted.The new SPC-2 benchmark was created, in part, to address new workloads for the Media and Entertainmentindustry. (For a comparison of the two, see my post [SPC benchmarks for Disk System Performance])
However, other attributes, like "easy to manage", are not as straightforward to measure.One client compared the complexity of different solutions by counting the number of cables involved to connect the various parts of each solution. Only external cables were considered. All of the cables inside an IBM SystemStorage DS8000 would not be counted. By this measure, a single IBM System z10 EC mainframe connected to a single IBM DS8000 disk system over a few FICON cables would therefore be "less complicated" than a thousand x86 servers connectedvia FCP SAN switches to dozens of disk systems.
But counting cables only handles the hardware part of the interconnections. You have to also considerthe interconnections between the software, between users, and between IT administrators. It is not alwaysobvious where those connections are, and how to count them into consideration.
This month, IBM introduced the first "Management Complexity Factor" (MCF) for the Media andEntertainment industry. IBM MCF a result of IBM's acquisition of NovusCG, and is an essential part of"Storage Optimization Services" being offered by IBM. Here is an excerpt from the[IBM Press Release]:
"Media companies are facing a double-edged sword with the exponential rise in digital media storage needs, coupled with concerns about optimizing storage to be more efficient," said Steve Canepa, vice president of Media and Entertainment, IBM. "By quickly and cost-effectively analyzing the interconnected IT and storage environments that increasingly comprise media operations, MCF for Media helps our clients identify opportunities for improvement and align their IT and business strategies."
Since 1995, IBM has invested more than $18 billion on public acquisitions, making it the most acquisitive company in the technology industry, based on volume of transactions.
IBM has a strong global focus on the media and entertainment industry across all of its services and products, serving all the major industry segments -- entertainment, publishing, information providers, media networks and advertising.
My theme this week was to focus on "Do-it-Yourself" solutions, such as the "open storage" concept presentedby Sun Microsystems, but it has morphed into a discussion on vendor lock-in. Both deserve a bit of furtherexploration.
There were several reasons offered on why someone might pursue a "Do-it-Yourself" course of action.
Building up skills
In my post [Simply Dinners and Open Storage], I suggested that building a server-as-storage solution based on Sun's OpenSolaris operating system could serve to learn more about [OpenSolaris], and by extension, the Solaris operating system.Like Linux, OpenSolaris is open source and has distributions that run on a variety of chipsets, from Sun's ownSPARC, to commodity x86 and x86-64 hardware. And as I mentioned in my post [Getting off the island], a version of OpenSolaris was even shown to run successfully on the IBM System z mainframe.
"Learning by Doing" is a strong part of the [Constructivism] movement in education. TheOne Laptop Per Child [OLPC] uses this approach. IBM volunteers in Tucson and 40other sites [help young students build robots]constructed from [Lego Mindstorms]building blocks.Edward De Bono uses the term [operacy] to refer to the"skills of doing", preferred over just "knowing" facts and figures.
However, I feel OpenSolaris is late to the game. Linux, Windows and MacOS are all well-established x86-based operating systems that most home office/small office users would be familiar with, and OpenSolaris is positioning itself as "the fourth choice".
In my post[WashingtonGets e-Discovery Wakeup Call], I suggested that the primary motivation for the White House to switch from Lotus Notes over to Microsoft Outlookwas familiarity with Microsoft's offerings. Unfortunately, that also meant abandoning a fully-operational automated email archive system, fora manual do-it-yourself approach copying PST files from journal folders.
Familiarity also explains why other government employees might print out their emails and archive them on paperin filing cabinets. They are familiar with this process, it allows them to treat email in the same manner as they have treated paper documents in the past.
Cost, Control and Unique Requirements
The last category of reasons can often result if what you want is smaller or bigger than what is availablecommercially. There are minimum entry-points for many vendors. If you want something so small that it is notprofitable, you may end up doing it yourself. On the other end of the scale, both Yahoo and Google ended up building their data centers with a do-it-yourself approach, because no commercial solutions were available atthe time. (IBM now offers [iDataPlex], so that has changed!)
While you could hire a vendor to build a customized solution to meet your unique requirements, it might turn outto be less costly to do-it-yourself. This might also provide some added control over the technologies and components employed. However, as EMC blogger Chuck Hollis correctly pointed out for[Do-it-yourself storage],your solution may not be less costly than existingoff-the-shelf solutions from existing storage vendors, when you factor in scalability and support costs.
Of course, this all assumes that storage admins building the do-it-yourself storage have enough spare time to do so. When was the last time your storage admins had spare time of any kind?Will your storage admins provide the 24x7 support you could get from established storage vendors? Will theybe able to fix the problem fast enough to keep your business running?
From this, I would gather that if you have storage admins more familiar with Solaris than Linux, Windows or MacOS,and select commodity x86 servers from IBM, Sun, HP, or Dell, they could build a solution that has less vendor lock-in than something off-the-shelf from Sun. Let's explore the fears of vendor lock-in further.
The storage vendor goes out of business
Sun has not been doing so well, so perhaps "open storage" was a way to warn existing Sun storage customers thatbuilding your own may be the next alternative.The New York Times title of their article says it all:["Sun Microsystems Posts Loss and Plans to Reduce Jobs"]. Sun is a big company, so I don't expect them to close their doors entirely this year,but certainly fear of being locked-in to any storage vendor's solution gets worse if you fear the vendor might go out of business.
The storage vendor will get acquired by a vendor you don't like
We've seen this before. You don't like vendor A, so you buy kit from vendor B, only to have vendor A acquire vendorB after your purchase. Surprise!
The storage vendor will not support new applications, operating systems, or other new equipment
Here the fear is that the decisions you make today might prevent you from choices you want to make in the future.You might want to upgrade to the latest level of your operating system, but your storage vendor doesn't supportit yet. Or maybe you want to upgrade your SAN to a faster bandwidth speed, like 8 Gbps, but your storage vendordoesn't support it yet. Or perhaps that change would require re-writing lots of scripts using the existingcommand line interfaces (CLI). Or perhaps your admins would require new training for the new configuration.
The storage vendor will raise prices or charge you more than you expect on follow-on upgrades
For most monolithic storage arrays, adding additional disk capacity means buying it from the same vendor as the controller. I heard of one company recently who tried to order entry-level disk expansion drawer, at a lower price, solely to move the individual disk drives into a higher-end disk system. Guess what? It didn't work. Most storage vendors would not support such mixed configurations.
If you are going to purchase additional storage capacity to an existing disk system, it should cost no more thanthe capacity price rate of your original purchase. IBM offers upgrades at the going market rate, but not all competitors are this nice. Some take advantage of the vendor lock-in, charging more for upgrades and pocketing the difference as profit.
Vendor lock-in represents the obstacles in switching vendors in the event the vendor goes out of business, failsto support new software or hardware in the data center, or charges more than you are comfortable with. These obstacles can make it difficult to switch storage vendors, upgrade your applications, or meet otherbusiness obligations. IBM SANVolume Controller and TotalStorage Productivity Center can help reduce or eliminate many of these concerns. IBMGlobal Services can help you, as much or as little, as you want in this transformation. Here are the four levelsof the do-it-yourself continuum:
Let me figure it out myself
Tell me what to do
Help me do it
Do it for me
This is the self-service approach. Go to our website, download an [IBM Redbook], figure out whatyou need, and order the parts to do-it-yourself.
IBM Global Business Services can help understand your business requirementsand tell you what you need to meet them.
IBM Global Technology Services can help design, assemble and deploy asolution, working with your staff to ensure skill and knowledge transfer.
IBM Managed Storage Services can manage your storage, on-site at your location, or at an IBM facility. IBM provides a varietyof cloud computing and managed hosting services.
So, if you are currently a Sun server or storage customer concerned about these latest Sun announcements, give IBM a call, we'll help you switch over!