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, we had another successful event in Second Life today.
Unlike our April 26 launch of our System Storage products for IBM Business Partners only, this time we decided this time to make it as a "Meet the Storage Experts" Q&A Panel format, and open up registration to everyone. Thesubject matter experts sat at the front of the room on four stools. We had six rows of chairs arrangedsemi-circularly.
Shown above, from left to right, are the avatars of our four experts:
IBM System Storage N series, focusing on recent N3000 disk system announcements
Harold Pike (holding the microphone while speaking)
IBM System Storage DS3000 and DS4000 series, focusing on recent DS3000 disk system announcements
IBM System Storage TS series, focusing on recent TS2230, TS3400 and TS7700 tape system announcements
IBM storage networking, focusing on recent IBM SAN256B director blade announcements
While Eric was a veteran Second Lifer, having presented at our April event, the other three were trainedon how to raise their hand, speak into the microphone, sit on the stool, and so on. I want to thank allof our experts for putting in this effort!
The event was produced by Katrina H Smith. She did a great job, and made sure we were on top ofall the issues and tasks required to get the job done. Running a Second Life event is every bit ashard as running a real face-to-face event. We had several meetings to discuss venue details, placementof chairs, placement of product demos, audio/video recording, wall decorations, tee-shirt and coffee mug design, logistics, and so on.
I acted as moderator/emcee for the event. That is my back in the picture above. The process wassimple, modeled after the "Birds of a Feather" sessions at events like SHARE and the IBMStorage and Storage Networking Symposium. We threw out a list of topics the experts would cover,and people in the audience would "raise their left hand". I, as the moderator, would then walkover to each person, and hold out the microphone for them to ask the question. I would then repeat the question and ask the appropriate expert to provide an answer. We defined gestures onhow to "raise hand" and "put hand down" that we gave to each registered participant.
We had four dedicated "camera-avatars" in world to capture both video and screenshots.Our video editors are now working to edit "highlight videos" that we can use at future events, for training materials, and for our internal "BlueTube" online video system.
The room was filled with examples of each of our products, made into 3D objects that were dimensionallycorrect, and "textured" with photographs of the actual products. If you click on an object, you get a "notecard" that provided more information. Special thanks to Scott Bissmeyer for making all of theseobjects for us.
We made posters of each expert and placed them in all four corners of the room. On the bottom of each coffee mug was a picture of each of the experts, and if you walked under each of the posters, you were"dispensed" a coffee mug matching the expert shown in the poster.Participants could "Collect all Four!" When you bring the coffee mug up to takea sip, the picture on the bottom of the mug is exposed for all to see.And as a final give-away to the audience, we made a variety of event tee-shirts and polo-shirts.
At the end of the session, we asked everyone to click on the "Survey" kiosk near the exit door. We askedsix simple questions using SurveyMonkey.com that took only a fewminutes to process. We found asking questions immediately at the end of the event was the best way tocapture this feedback.
From a "Green" perspective, we had people registered from the following countries: US, India, Mexico,Australia, United Kingdom, Brazil, Germany, Argentina, Chile, China, Canada, and Venezuela. Second Lifeallows all these people who probably could not travel, or could not afford the time and expense to travel,to participate in a simulated face-to-face meeting without energy consumption of traditional travel methods.
More importantly, we got several leads for business. People often ask "Yes, but is there any businessassociated with this?" This time, there was, based on the answers to the questions, several avatars asked for a real sales call to follow-up on the products and offerings they were discussed.
With such a great success, we have already scheduled our next Second Life event, November 8. Mark your calendars! I'll postmore details on the registration process of the November event when available.
For those of us in the northern hemisphere, yesterday was this year's Winter Solstice, representingthe shortest amount of daylight between sunrise and sunset. So today, I thought I would blog on my thoughtsof managing scarcity.
Earlier in my career, I had the pleasure to serve as "administrative assistant" to Nora Denzel for the week at a storage conference. My job was to make her look good at the conference, which if you know Nora, doesn't take much. Later, she left IBM to work at HP, and I gotto hear her speak at a conference, and the one thing that I remember most was her statement that thewhole point of "management" was to manage scarcity, as in not enough money in the budget,not enough people to implement change, or not enough resources to accomplish a task.(Nora, I have no idea where you are today, so if you are reading this, send me a note).
Of course, the flip-side to this is that resources that are in abundance are generallytaken for granted. Priorities are focused on what is most scarce. Let's examine some of theresources involved in an IT storage environment:
Capacity - while everyone complains that they are "running out of space", the truth is that most external disk attached to Linux, UNIX, or Windows systems contain only 20-40% data. Many years ago, I visitedan insurance company to talk about a new product called IBM Tivoli Storage Manager. This company had 7TB of disk on their mainframe,and another 7TB of disk scattered on various UNIX and Windows machines. In the room were TWO storage admins for
the mainframe, and 45 storage admins for the distributed systems. My first question was "why so many people forthe mainframe, certainly one of you could manage all of it yourself, perhaps on Wednesday afternoons?" Their response was that they acted as eachother's backup, in case one goes on vacation for two weeks. My follow-up question to the rest of the audience was:"When was the last time you took two weeks vacation?" Mainframes fill their disk and tape storage comfortablyat over 80-90% full of data, primarily because they have a more mature, robust set of management software, likeDFSMS.
Labor - by this I mean skilled labor able to manage storage for a corporation. Some companies I have visitedkeep their new-hires off production systems for the first two years, working only on test or development systemsonly until then. Of course, labor is more expensive in some countries than others. Last year, I was doing a whiteboard session on-site for a client in China, and the last dry-erase pen ran out of ink. I asked for another pen, and they instead sent someone to go re-fill it. I asked wouldn't it be cheaper just to buy another pen, and they said "No, labor is cheap, but ink is expensive." Despite this, China does complain that there is a shortage of askilled IT labor force, so if you are looking for a job, start learning Mandarin.
Power and Cooling - Most data centers are located on raised floors, with large trunks of electrical power and hugeair conditioning systems to deal with all the heat generated from each machine. I have visited the data centers ofclients that are forced now to make decisions on storage based on power and cooling consumption, because the coststo upgrade their aging buildings are too high. Leading the charge is IBM, with technology advancements in chips, cards, and complete systems that use less power, and generate less heat. While energy is still fairly cheap in the grand scheme of things, fears ofGlobal Warmingand declining oil supplies, the costs ofpower and cooling have gotten some news lately. In 1956, Hubbert predicted US would reach peak oil supplies by1965-1970 (it happened in 1971), and this year Simmonsestimated that world-wide oil production began its decline already in 2005. Smart companies like Google have movedtheir server farms to places like Oregon in the Pacific Northwest for cheaper hydroelectric power.
Bandwidth - Last year IBM introduced 4Gbps Fibre Channel and FICON SAN networking gear, along with the servers and storage needed to complete the solution. 4Gbps equates to about 400 MB/sec in data throughput. By comparison, iSCSI is typically run on 1Gbps Ethernet, but has so much overheads that you only get abour 80 MB/sec. Next year, we may see both 8 Gbps SAN, and 10 GbE iSCSI, to provide 800 MB/sec throughputs. My experience is that the SAN is not the bottleneck, instead people run out of bandwidth at the server or storage end first. They may not have a million dollars to buy the fastest IBM System p5 servers, or may not have enough host adapters at the storage system end.
Floorspace - I end with floorspace because it reminds me that many "shortages" are temporary or artificially created. Floorspace is only in short supply because you don't want to knock down a wall, or build a new building, to handle your additional storage requirements.In 1997, Tihamer Toth-Fejel wrote an article for the National Space Society newsletter that estimated that ...Everybody on Earth could live comfortably in the USA on only 15% of our land area, with a population density between that of Chicago and San Francisco. Using agricultural yields attained widely now, the rest of the U.S. would be sufficient to grow enough food for everyone. The rest of the planet, 93.7% of it, would be completely empty.Of course, back in 1997 the world population was only 5.9 billion, and this year it is over 6.5 billion.
This last point brings me back to the concept of food, and I am not talking about doughnuts in the conference room, or pizza while making year-end storage upgrades. I'm talking aboutthe food you work so hard to provide for yourself and your family. The folks at Oxfam came up with a simpleanalogy. If 20 people sit down at your table, representing the world’s population:
3 would be served a gourmet, multi-course meal, while sitting at decorated table and a cushioned chair.
5 would eat rice and beans with a fork and sit on a simple cushion
12 would wait in line to receive a small portion of rice that they would eat with their hands while sitting on the floor.
So for those of you planning a special meal next Monday, be thankful you are one of the lucky three, and hopefulthat IBM will continue to lead the IT industry to help out the other seventeen.
Lakota Industries made news with the introduction of its [Sarah-Cuda Hunting Bow], named after moose-huntingU.S. Vice President nominee and Governor of Alaska [Sarah Palin]. This has all the same features as their other high-end hunting bows, but is lighter, smaller and available in Pink Camo. This "pink-it-and-shrink-it" move was designed to broaden the market share of hunting bows by reaching out to the needs of women hunters.
Not to be outdone, today, at the Storage Networking World Conference, IBM announced the new IBM System Storage SAN Volume Controller Entry Edition [SVC EE].
The new SVC Entry Edition, available in Flamingo Pink* or traditional Raven Black.
* RPQ required. Default color is Raven Black.
You might be thinking: "Wait! IBM SVC is already the leading storage virtualization product among SMB clients today,why introduce a less expensive model?" With the global economy in the tank, IBM thought it would be nice to help outour smaller SMB clients with this new option.
This new offering is actually a combination of new software (SVC 4.3.1) and new hardware (2145-8A4). Here are thekey differences:
by usable capacity managed, up to 8 PB
by number of disk drives, up to 60 drives
2145-4F2, 8F2, 8F4, 8G4, 8A4
1, 2, 3 or 4 node-pairs, depending on performance requirements
only one node-pair needed
FlashCopy, Metro Mirror and Global Mirror, licensed by subset of capacity used
FlashCopy, Metro Mirror and Global Mirror, but with simplified licensing
The SVC EE is not a "dumbed-down" version of the SVC Classic. It has all the features and functions of theSVC Classic, including thin provisioning with "Space-efficient volumes", Quality of Service (QoS) performance prioritization for more important applications, point-in-time FlashCopy, and both synchronous and asynchronous disk mirroring (Metro and Global Mirror).
While IBM has not yet have SPC-1 benchmarks published, IBM is positioning the SVC EE as roughly 60 percent of the performance, at 60 percent of the list price, compared to a comparable SVC Classic 2145-8G4 configuration. The SVC Classic is already one of the fastest disk systems in the industry. By comparison, the SVC EE is twice as fast as the original SVC 2145-4F2 introduced five years ago.If you outgrow the SVC EE, no problem! The 2145-8A4 can be used in traditional SVC Classic mode, and the SVC EE software can be converted into the SVC Classic software license for upgrade purposes, protecting your originalinvestment!
For those considering an HP EVA 4400 or EMC CX-4 disk system, you might want to look at combining an SVC EE with [IBM System Storage DS3400] disk. The combination offers more features and capabilities, and helps reduce your IT costs at the same time.
And if you are worried you can't afford it right now, IBM Global Financing is offering a ["Why Wait?" world-wide deferral of interest and payments] for 90 days, so you don't have to make your first payment until 2009, applicable to all IBM System Storage products, including the SVC EE, SVC Classic and DS3400 disk systems.
Use more efficient disk media, such as high-capacity SATA disk drives
Both are great recommendations, but why limit yourself to what EMC offers? Your x86-based machines are only a subset of your servers,and disk is only a subset of your storage. IBM takes a more holistic approach, looking at the entire data center.
VMware is a great product, and IBM is its top reseller. But in addition to VMware, there are other solutions for the x86-based servers, like Xen and Microsoft Virtual Server. IBM's System p, System i, and System z product lines all support logical partitioning.
To compare the energy effectiveness of server virtualization, consider a metric that can apply across platforms. For example, for an e-mail server, consider watts per mailbox. If you have, say, 15,000 users, you can calculate how many watts you are consuming to manage their mailboxes on your current environment, and compare that with running them on VMware, or logical partitions on other servers. Some people find it surprising that it is often more cost-effective, and power-efficient, to run workloads on mainframe logical partitions (LPARs) than a stack of x86 servers running VMware.
More efficient Media
SATA and FATA disks support higher capacities, and run at slower RPM speeds, thus using fewer watts per terabyte.A terabyte stored on 73GB high-speed 15K RPM drives consumes more watts than the same terabyte stored using 500GB SATA.Chuck correctly identifies that tape is more power-efficient than disk, but then argues that paper is more power-efficient than tape. But paper is not necessarily more efficient than tape.
ESG analyst Steve Duplessie divides up data betweenDynamic vs. Persistent. The best place to put dynamic data is on disk, and here is where evaluation of FC/SAS versus SATA/FATA comes into play.Persistent data, on the other hand, can be stored on paper, microfiche, optical or tape media. All of these shelf-resident media consume no electricity, nor generate any heat that would require additional cooling.
A study by scientists at the Lawrence Berkeley National Laboratory titled High-Tech Means High-Efficiency: The Business Case for Energy Management in High-Tech Industries indicates thatData centers consume 15 to 100 times more energy per square foot than traditional office space. Storing persistent data in traditional office space can save a huge amount of energy. Steve Duplessie feels the ratio of dynamic to persistent data is 1:10 today, but is likely to grow to 1:100 in the near future, raising the demand for energy-efficient storage of persistent data ever more important to our environment.
Data centers consume nearly 5000 Megawatts in the USA alone, 14000 Megawatts worldwide. To put that in perspective, the country of Hungary I was in last week can generate up to 8000 Megawatts for the entire country (and they were using 7400 Megawatts last week as a result of their current heat wave, causing them grave concern).
Back in the 1990's, one of the insurance companies IBM worked with kept data on paper in manila folders, and armiesof young adults in roller skates were dispatched throughout the large warehouses of shelves to get the appropriate folder in response to customer service inquiries. Digitizing this paper into electronic format greatly reduced the need for this amount of warehouse space, as well as improved the time to retrieve the data.
A typical file storage box (12 inch x 12 inch x 18 inch) containing typed pages single-spaced, double-sided, 12 point font could hold perhaps 100MB. The same box could hold a hundred or more LTO or 3592 tape cartridges, each storing hundreds of GB of information. That's a million-to-one improvement of space-efficiency, and from a watts-per-TB basis, translates to substantial improvement in standard office air conditioning and lighting conditions.
To learn more about IBM's Project Big Green, watch thisintroductory video which used Second Life for the animation.
Whew! I am glad that is over. The BarryB circus has left town, he has decided to [move on to other topics], and I am now to clean up the ["circus gold"] leftbehind. I would like to remind everyone that all of these discussions have been about the architecture,not the product. IBM will come out withits own version of a product based on Nextra later in 2008, which may be different than the product that XIV currentlysells to its customers.
RAID-X does not protect against double-drive failures as well as RAID-6, but it's very close
BarryB calls this the "Elephant in the room", that RAID-6 protects better against double-drive failures. I don't dispute that. He also credits me with the term "RAID-X", but I got this directly from the XIV guys. It turns out this was already a term used among academic research circles for [distributed RAID environments]. Meanwhile, Jon Toigo feels the term RAID-X sounds like a brand of bug spray in his post[XIV Architecture: What’s Not to Like?]Perhaps IBM can change this to RAID-5.99 instead.
If you measure risk of a second drive failing during the rebuild or re-replication process ofa first drive failure, you can measure the exposure by multiplying the amount of GB at risk by thenumber of hours that the second failure could occur, resulting in a unit of "GB-hours". Here Ilist best-case rebuild times, your mileage may vary depending on whether other workloads existon the system competing for resources. Notice that 8-disk configurations of RAID-10 and RAID-5for smaller FC disk are in the triple digits, and larger SATA disk in five digits, but that with RAID-X it is only single digits. That is orders of magnitude closer to the ideal.
For each RAID type, the risk is proportional to the square of the individual drive size.Double the drive size causes the risk to be four times greater.This is not the first time this has been discussed. In [Is RAID-5 Getting Old?], Ramskovquotes NetApp's response in Robin Harris' [NetApp Weighs In On Disks]:
...protecting online data only via RAID 5 today verges on professional malpractice.
As disks get older, RAID-6 will not be able to protect against 3-drive failures. A similar chartabove could show the risk to data after the second drive fails and both rebuilds are going on,compared to the risk of a third drive failure during this time. The RAID-X scheme protects muchbetter against 3-drive failures than RAID-6.
Nothing in the Nextra architecture prevents a RAID-6, Triple-copy, or other blob-level scheme
In much the same way that EMC Centera is RAID-5 based for its blobs, there is nothing in the Nextra architecturethat prevents taking additional steps to provide even better protection, using a RAID-6 scheme, making three copiesof the data instead of two copies, or something even more advanced. The current two-copy scheme for RAID-X is betterthan all the RAID-5 and RAID-10 systems out in the marketplace today.
Mirrored Cache won't protect against Cosmic rays, but ECC detection/correction does
BarryB incorrectly states that since some implementations of cache are non-mirrored, that this implies they are unprotected against Cosmic rays. Mirroring does not protect against bit-flips unless both copies arecompared for differences. Unfortunately, even if you compared them, the best you can do is detect theyare different, there is no way of knowing which version is correct.Mirroring cache is normally done to protect uncommitted writes. Reads in cacheare expendable copies of data already written to disk, so ECC detection/correction schemes are adequateprotection. ECC is like RAID for DRAM memory. A single bit-flip can be corrected, multiple bit-flipscan be detected. In the case of detection, the cache copy is discarded and read fresh again from disk.IBM DS8000, XIV and probably most other major vendor offerings use ECC of some kind. BarryB is correctthat some cheaper entry-level and midrange offerings from other vendors might cut corners in this area.I don't doubt BarryB's assertion that the ECC method used in the EMC products may be differently implemented than theECC in the IBM DS8000, but that doesn't mean the IBM DS8000's ECC implementation is flawed.
ECC protection is important for all RAID systems that perform rebuild, and even more importantthe larger the GB-hours listed in the table above.
XIV is designed for high-utilization, not less than 50 percent
I mentioned that the typical Linux, UNIX or Windows LUN is only 30-50 percent full, and perhaps BarryBthought I was referring to the typical "XIV customer". This average is for all disk storage systems connectedto these operating systems, based on IBM market research and analyst reports. The XIV is expected to run at much higher utilization rates, and offers features like "thin provisioning" and "differential snapshot" to make this simple to implement in practice.
Most often, disks don't fail without warning. Usually, they give out temporary errors first, and then fail permanently.The XIV architecture allows for pre-emptive self-repair, initiating the re-replication process after detecting temporary errors, rather than waiting for a complete drive failure.
I had mentioned that this process used "spare capacity, not spare drives" but I was notified that there are three spare drives per system to ensure that there is enough spare capacity, so I stand corrected.
New drives don't have to match the same speed/capacity as the new drives, so three to five years from now, whenit might be hard to find a matching 500GB SATA drive anymore, you won't have to.
No RAID scheme eliminates backups or Business Continuity Planning
The XIV supports both synchronous and asynchronous disk mirroring to remote locations. Backup software willbe able to backup data from the XIV to tape. A double drive failure would require a "recovery action", eitherfrom the disk mirror, or from tape, for the few GB of data that need to be recovered.
A third alternative is to allow end-users to receive backups of their own user-generated content. For example, I have over 15,000 photos uploaded over the past six years to Kodak Photo Gallery, which I use to share with my friends and family. For about $180 US dollars, they will cut DVDs containing all of my uploaded files and send them to me, so that I do not have to worry about Kodak losing my photos.In many cases, if a company or product fails to deliver on its promises, the most you will get is your money back, but for "free services" like HotMail, FreeDrive, FlickR and others, you didn't pay anything in the first place, andthey may point this limitation of liability in the "terms of service".
XIV can be used for databases and other online transaction processing
The XIV will have FCP and iSCSI interfaces, and systems can use these to store any kind of data you want. I mentionedthat the design was intended for large volumes of unstructured digital content, but there is nothing to prevent the use of other workloads. In today's Wall Street Journal article[To Get Back Into the Storage Game, IBM Calls In an Old Foe]:
Today, XIV's Nextra system is used by Bank Leumi, a large Israeli bank, and a few other customers for traditional data-storage tasks such as recording hundreds of transactions a minute.
BarryB, thanks for calling the truce. I look forward to talking about other topics myself. These past two weeks have been exhausting!
We've been quite busy here at the Tucson Executive Briefing Center. I am often asked to explain the relationship between IBM's various storage products. While automakers don't have to explain why they sell sports coupes, pickup trucks and minivans, this analogy does not adequately cover IT storage products. So, I have come up with a new analogy that seems to be a better fit: foundations and flavorings.
All over the world, meals are often comprised of a foundation, perhaps rice, potatoes or pasta, covered with some form of flavoring, sauces, pieces of meat or fish, grated cheese and spices. In Puerto Rico, I had dishes where the foundation was mashed bananas called [plantains]. Sandwich shops often let you pick your choice of bread, the foundation, and then your meats and cheeses, the flavorings.At our local steakhouse,[McMahon's], the menulists a set of steaks, the foundation such as Rib Eye, Filet Mignon, Prime Rib or New York Strip, andvarious flavorings, such as sauces and rubs to cover the steak. Last night, I had the Delmonico steak with the Cristiani sauce consisting of Portobello mushrooms, garlic and aged Romano cheese.
This serves as a useful analogy for IBM's storage strategy. Allowing thefoundations and flavorings to be separately orderable greatly simplifies the selection menu and providesa nearly any-to-any approach to meeting a variety of client needs.Let's take a look at both.
IBM's foundation products are the DS family [DS3000, DS4000, DS5000, DS6000 and DS8000 series], [DS9900 series], and [XIV] for disk, and the TS family [TS1000, TS2000, TS3000] series for tape drives and libraries. In much thesame way you might prefer brown rice instead of white rice, or linguine instead of penne pasta, you might find the attributes of one storagefoundation more attractive based on its performance, scalability and availability features for yourparticular application workloads.
Fellow IBM blogger Barry Whyte discusses SVC at great length on his [Storage Virtualization] blog. Flavoring disk foundation storage with SAN Volume Controller can provide you additionalfeatures and functions, and help improve the scalability, performance or availability characteristics.For example, if you have DS4000, DS8000 and XIV, you might use SVC to provide a consistent methodologyfor asynchronous replication, a form of consistent "flavoring" if you will.
N series Gateways
The [N series gateways] offerflavoring to disk foundation, including unified NAS, iSCSI and FCP protocol host attachment, and application aware capabilities. (As for our IBM N series appliances or "filers", these could be foundational storage behind an SVC, but that's perhaps a topic for another post.)
SoFS provides a global namespace with clustered NAS access to files. This is a blended disk-and-tape solution with built-in backup and Information Lifecycle Management [ILM]. Policies can be used to place different files onto different tiers of storage, automate the movement from tier to tier, including migration to tape, and even expiration when the data is no longer needed.
The [IBM System Storage DR550] provides Non-erasable, Non-rewriteable (NENR) flavoring to storage. While the DR550 comes with internal disk storage, it can front end a tape library filled with WORM cartridges. The DR550 hasbeen paired up with small libraries (TS3200 or TS3310) as well as larger libraries like the TS3500.
The IBM Grid Medical Archive Solution [GMAS] provides a variety of capabilities for storing and accessing medical images, using a blended disk-and-tape approach. This allows hospital and clinicnetworks to provide access for doctors and radiologists from multiple locations.
Many of the flavorings are called "gateways". The IBM TS7650G flavors disk that provides a virtualtape library[VTL] with inline data deduplication capability. Recent performance tests pairing the TS7650G flavoring with XIV foundation storage found this combination to be an excellent match.
Let me know what you think. Does this help you understand IBM's storage strategy and acquisitions? Enteryour comments below.
On his The Storage Architect blog, Chris Evans wrote [Twofor the Price of One]. He asks: why use RAID-1 compared to say a 14+2 RAID-6 configuration which would be much cheaper in terms of the disk cost? Perhpaps without realizing it, answers itwith his post today [XIV part II]:
So, as a drive fails, all drives could be copying to all drives in an attempt to ensure the recreated lost mirrors are well distributed across the subsystem. If this is true, all drives would become busy for read/writes for the rebuild time, rather than rebuild overhead being isolated to just one RAID group.
Let me try to explain. (Note: This is an oversimplification of the actual algorithm in an effortto make it more accessible to most readers, based on written materials I have been provided as partof the acquisition.)
In a typical RAID environment, say 7+P RAID-5, you might have to read 7 drives to rebuild one drive, and in the case of a 14+2 RAID-6, reading 15 drives to rebuild one drive. It turns out the performance bottleneck is the one driveto write, and today's systems can rebuild faster Fibre Channel (FC) drives at about 50-55 MB/sec, and slower ATA disk at around 40-42 MB/sec. At these rates, a 750GB SATA rebuild would take at least 5 hours.
In the IBM XIV Nextra architecture, let's say we have 100 drives. We lose drive 13, and we need to re-replicate any at-risk 1MB objects.An object is at-risk if it is the last and only remaining copy on the system. A 750GB that is 90 percent full wouldhave 700,000 or so at-risk object re-replications to manage. These can be sorted by drive. Drive 1 might have about 7000 objects that need re-replication, drive 2might have slightly more, slightly less, and so on, up to drive 100. The re-replication of objects on these other 99 drives goes through three waves.
Select 49 drives as "source volumes", and pair each randomly with a "destination volume". For example, drive 1 mapped todrive 87, drive 2 to drive 59, and so on. Initiate 49 tasks in parallel, each will re-replicate the blocks thatneed to be copied from the source volume to the destination volume.
50 volumes left.Select another 49 drives as "source volumes", and pair each with a "destination volume". For example, drive 87 mapped todrive 15, drive 59 to drive 42, and so on. Initiate 49 tasks in parallel, each will re-replicate the blocks thatneed to be copied from the source volume to the destination volume.
Only one drive left. We select the last volume as the source volume, pair it off with a random destination volume,and complete the process.
Each wave can take as little as 3-5 minutes. The actual algorithm is more complicated than this, as tasks complete early the source and volumes drives are available for re-assignment to another task, but you get the idea. XIV hasdemonstrated the entire process, identifying all at-risk objects, sorting them by drive location, randomly selectingdrive pairs, and then performing most of these tasks in parallel, can be done in 15-20 minutes. Over 40 customershave been using this architecture over the past 2 years, and by now all have probably experienced at least adrive failure to validate this methodology.
In the unlikely event that a second drive fails during this short time, only one of the 99 task fails. The other 98 tasks continue to helpprotect the data. By comparison, in a RAID-5 rebuild, no data is protected until all the blocks are copied.
As for requiring spare capacity on each drive to handle this case, the best disks in production environments aretypically only 85-90 percent full, leaving plenty of spare capacity to handle re-replication process. On average,Linux, UNIX and Windows systems tend to only fill disks 30 to 50 percent full, so the fear there is not enough sparecapacity should not be an issue.
The difference in cost between RAID-1 and RAID-5 becomes minimal as hardware gets cheaper and cheaper. For every $1 dollar you spend on storage hardware, you spend $5-$8 dollars managing the environment. As hardware gets cheaper still, it might even be worth making three copies of every 1MB object, the parallel processto perform re-replications would be the same. This could be done using policy-based management, some data gets triple-copied, and other data gets only double-copied, based on whether the user selected "premium" or "basic" service.
The beauty of this approach is that it works with 100 drives, 1000 drives, or even a million drives. Parallel processingis how supercomputers are able to perform feats of amazing mathematical computations so quickly, and how Web 2.0services like Google and Yahoo can perform web searches so quickly. Spreading the re-replication process acrossmany drives in parallel, rather than performing them serially onto a single drive, is just one of the many uniquefeatures of this new architecture.
The proof-of-concept that IBM Haifa research center developed back in 1998 became what we now call the iSCSI protocol.The book iSCSI: The Universal Storage Connection introduces the history as follows:
In the fall of 1999 IBM and Cisco met to discuss the possibility of combining their SCSI-over-TCP/IP efforts. After Cisco saw IBM's demonstration of SCSI over TCP/IP, the two companies agreed to develop a proposal that would be taken to the IETF for standardization.
There are three ways to introduce iSCSI into your data center:
Through a gateway, like the IBM System Storage N series gateway, that allows iSCSI-based servers connect to FC-based storage devices
Through a SAN switch or director, a FC-based server can access iSCSI-based storage, an iSCSI-based server accessing FC-based storage, or even iSCSI-based servers attaching to iSCSI-based storage.
Directly through the storage controller.
IBM has been delivering the first method with its successful IBM System Storage N series gateway products, buttoday we have announced additional support for the second and third methods.Here's a quick recap.
New SAN director blades
Supporting the second method, IBM TotalStorage SAN256B Director is enhanced to deliver iSCSI functionality with a new M48 iSCSI Blade, which includes 16 ports (8 Fibre Channel ports; and 8 Ethernet ports for iSCSI connectivity). We also announced a new Fibre Channel M48 Blade which provides 10 Gbps Fibre Channel Inter Switch Link (ISL) connectivity between SAN256B Directors.
With support for Boot-over-iSCSI, diskless rack-optimized and blade servers can boot Windows or Linux over Ethernet,eliminating the management hassles with internal disk.
All of this is part of IBM's overall push into the Small and Medium size Business marketplace, making it easier to shop for and buy from IBM and its many IBM Business Partners, easier to deploy and install storage, and easier tomanage the storage once you have it.
I've blogged about some of these videos already, but since there are probably a few out there buying the brand new Apple iPhone looking for YouTube videos to play on them, these links might provide some exampleentertainment on your new handheld device.
Next week has "Fourth of July" Independence Day holiday in the USA smack in the middle of the week, so I suspect the blogosphereto quiet down a bit. So whether you are working next week or not, in the USA or elsewhere, take some time to enjoy your friends and family.
Many people have asked me if there was any logic with the IBM naming convention of IBM Systems branded servers. Here's your quick and easy cheat sheet:
System x -- "x" for cross-platform architecture. Technologies from our mainframe and UNIX servers were brought into chips that sit next to the Intel or AMD processors to provide a more reliable x86 server experience. For example, some models have a POWER processor-based Remote Supervisor Adapter (RSA).
System p -- "p" for POWER architecture.
System z -- "z" for Zero-downtime, zero-exposures. Our lawyers prefer "near-zero", but this is about as close as you get to ["six-nines" availability] in our industry, with the highest level of security and encryption, no other vendor comes close, so you get the idea.
But what about the "i" for System i? Officially, it stands for "Integrated" in that it could integrate different applications running on different operating systems onto a [COMMON] platform. Options were available to insert Intel-based processor cards that ran Windows, or attach special cables that allowed separate System x servers running Windows to attach to a System i. Both allowed Windows applications to share the internal LAN and SAN inside the System i machine. Later, IBM allowed [AIX on System i] and [Linux on Power] operating systems to run as well.
From a storage perspective, we often joked that the "i" stood for "island", as most System i machines used internal disk, or attached externally to only a fewselected models of disk from IBM and EMC that had special support for i5/OS using a special, non-standard 520-byte disk block size. This meant only our popular IBM System Storage DS6000 and DS8000 series disk systems were available. This block size requirement only applies to disk. For tape, i5/OS supports both IBM TS1120 and LTO tape systems. For the most part,System i machines stood separate from the mainframe, and the rest of the Linux, UNIX and Windows distributed serverson the data center floor.
Often, when I am talking to customers, they ask when will product xyz be supported on System z or System i?I explained that IBM's strategy is not to make all storage devices connect via ESCON/FICON or support non-standard block sizes, but rather to get the servers to use standard 512-byte block size, Fibre Channel and other standard protocols.(The old adage applies: If you can't get Mohamed to move to the mountain, get the mountain to move to Mohamed).
On the System z mainframe, we are 60 percent there, allowing three of the five operating systems (z/VM, z/VSE and Linux) to access FCP-based disk and tape devices. (Four out of six if you include [OpenSolaris for the mainframe])But what about System i? As the characters on the popular television show [LOST] would say: It's time to get off the island!
Last week, IBM announced the new [i5/OS V6R1 operating system] with features that will greatly improve the use of external storage on this platform. Check this out:
POWER6-based System i 570 model server
Our latest, most powerful POWER processor brought to the System i platform. The 570 model will be the first in the System i family of servers to make use of new processing technology, using up to 16 (sixteen!) POWER6 processors (running at 4.7GHZ) in each machine.The advantage of the new processors is the increased commercial processing workload (CPW) rating, 31 percent greater than the POWER5+ version and 72 percent greater than the POWER5 version. CPW is the "MIPS" or "TeraFlops" rating for comparing System i servers.Here is the[Announcement Letter].
Fibre Channel Adapter for System i hardware
That's right, these are [Smart IOAs], so an I/O Processor (IOP) is no longer required! You can even boot the Initial Program Load (IPL) direclty from SAN-attached tape.This brings System i to the 21st century for Business Continuity options.
Virtual I/O Server (VIOS)
[VirtualI/O Server] has been around for System p machines, but now available on System i as well. This allows multiplelogical partitions (LPARs) to access resources like Ethernet cards and FCP host bus adapters. In the case of storage, the VIOS handles the 520-byte to 512-byte conversion, so that i5/OS systems can now read and write to standard FCP devices like the IBM System Storage DS4800 and DS4700 disk systems.
IBM System Storage DS4000 series
Initially, we have certified DS4700 and DS4800 disk systems to work with i5/OS, but more devices are in plan.This means that you can now share your DS4700 between i5/OS and your other Linux, UNIX and Windowsservers, take advantage of a mix of FC and SATA disk capacities, RAID6 protection, and so on.
To call [IBM PowerVM] the "VMware for the POWER architecture" would not do it quite justice. In combination with VIOS, IBM PowerVM is able to run a variety of AIX, Linux and i5/OS guest images.The "Live Partition Mobility" feature allows you to easily move guest images from one system to another, while they are running, just like VMotion for x86 machines.
And while we are on the topic of x86, PowerVM is also able to represent a Linux-x86 emulation base to run x86-compiled applications. While many Linux applications could be re-complied from source code for the POWER architecture "as is", others required perhaps 1-2 percent modification to port them over, and that was too much for some software development houses. Now, we can run most x86-compiled Linux application binaries in their original form on POWER architecture servers.
BladeCenter JS22 Express
The POWER6-based [JS22 Express blade] can run i5/OS, taking advantage of PowerVM and VIOS to access all of the BladeCenterresources. The BladeCenter lets you mix and match POWER and x86-based blades in the same chassis, providing theultimate in flexibility.
This month (September, 2006) marks our 50th anniversary of the disk system. The first disk system was the 350 Disk Storage Unit, designed to attach to the IBM 305 RAMAC mainframe computer, both introduced to the world in September, 1956.
Well it's Tuesday, which means its time to look at recent announcements.While I was on vacation last week, IBM made a lot of storage announcements October 23.Josh Krischer gives his summary on WikiBon [October 2007 Review].Austin Modine of the The Register went so far as to say that [IBM goes crazy with storage system updates].
IBM System Storage DS8000 series
This is "Release 3" software/microcode upgrades on our existing "Turbo" hardware.
IBM FlashCopy SE -- Here "SE" stands for Space Efficient. Rather than allocating a full 100% of the space for the FlashCopy destination, you can set aside just a fraction, and this will hold all the changed blocks, similar to whatIBM already offers on the DS4000 series.
Dynamic Volume Expansion -- In the past, if you needed more space for a LUN, you had to carve out a newer one elsewhere, and then copy the data over from the old to the new, leaving the old LUN around to be re-used or leftstranded. With this enhancement, you can just upgrade the LUN in place, making it bigger as needed, similar to whatIBM already offers on the DS4000 series and SAN Volume Controller. This applies to CKD volumes for the System zmainframe users out there as well.
Storage Pool Striping -- striping volumes across RAID ranks to eliminate or reduce hot-spots, and provide betterload balancing. Many used SAN Volume Controller in front of the DS8000 to do this, but now you can do it natively inthe DS8000 itself.
z/OS Global Mirror Multiple Reader -- for System z customers, "z/OS Global Mirror" is the new name for XRC. Thisenhancement improves the throughput of sending updates to the remote disaster recovery location.
DS Storage Manager enhancements, the element manager software has been enhanced, and is pre-installed on the new IBM System Storage Productivity Center, which I will talk about below.
Intermix of DS8000 machine types -- this is especially useful to allow new frames to have co-terminating warrantieswith the base units. In other words, as you expand your system, you can ensure that the entire chunk of iron runs outof warranty all at the same time, to simplify your decision making process to upgrade or contract for extended service.
One of the biggest complaints about IBM TotalStorage Productivity Center is that it is software that needs to beinstalled on its own server, and that this installation process can take a day or two. Why wait? Now you can havea hardware console that has the DS8000 Storage Manager software, SVC Admin Console software, and IBM TotalStorageProductivity Center "Basic Edition" pre-installed. Here are the key features.
Pre-installed and tested console
DS8000 R3 GUI integration
Cohabitation of SVC 4.2.1 GUI and CIMOM
Automated device discovery
Asset and capacity reporting, including tape library support
Our "Release 9" applies across the board, from N3000 to N5000 to N7000 series models, includingnew host bus adapters, and the new Data OnTAP 7.2.4 release level.
The Virtual File Manager (VFM) was announced as one of our latest [Storage Virtualization Solutions]. VFMprovides a global namespace that aggregates the file systems from Linux, UNIX, and Windows file servers, as well asN series storage, into a consolidated environment.
IBM's virtual tape library (VTL) for the distributed systems platform, has been enhanced to provide:
Up to 12TB of disk cache, using 750GB SATA disk.
F05 Tape Frames installed as TS7520 base units through a 32 port fibre channel switch
Support for LTO generation 4 tape drives, both as virtual tape drives and as physical tape drives within IBM automated tape libraries attached to the TS7520. This allows you to use Encryption capabilities of LTO4.
DS3000 series now supports SATA disk, and can be attached to AIX and Linux on System p servers. This appliesto the DS3200, DS3300 and DS3400 models.See the [DS3000 Announcement Letter] for more details.
Today, I'll cover the announcements related to our IBM System Storage N series disk systems, which ties inwith Valentines Day theme nicely. The phrase we use for "unified storage" is that N series allows you to "share the closet, not necessarily the clothes". Couples recognize the value of a shared closet over having one closet for just the man's clothes, and a separate closet for just the woman's clothes. (For some couples, the man's closet would be terribly under utilized!). By analogy, the N series allows you to share one solution for LUNs that can be accessed via FCP or iSCSI protocols, and NAS file systems that can be accessed via NFS and CIFS protocols. In most data centers, Windows and UNIX applications are about as likely to share files as men and women are to wear each other's clothes, so the analogy is in tact.
Let's take a look at what got announced:
N7700 and N7900
There are actually [eight new high-end N series] models. the N7900 has 4 processors and 32GB of cache. The N7700 has 2 processors and 16GB cache. Each has two appliance models (A11 single node and A21 dual node) and two gateway models (G11 single node and G21 dual node).
The appliance models support both FC and SATA disk. The N7900 A models support a maximum of 1176 drives; the N7700 A models supports 840 drives. The gateway models provide FCP, iSCSI and NAS host access through external disk attachment. The N7900 gateway models support 1176 LUNs on external disk systems; the N7700 gateway models support 840 external LUNs.
N series now supports 1 TB SATA disk
The [EXN1000 expansion drawer] can now have up to fourteen 1TB SATA drives. This is in addition to previousannouncements supporting 500GB and 750GB drive capacities. These drawer support the entire N series line.
With 1 TB drives, the N7900 now supports up to 1176 TB of raw capacity, which is over 1PB of usabledata in 12+2P RAID-DP mode. This is greater than the internal disk capacity limits of current IBM DS8000, EMC DMX andHDS USP-V models.
At the low end, both the N3300 and N3600 now support 500GB, 750GB and 1TB SATA drives in addition to the SASdrives they supported.
SnapManager for Microsoft SharePoint
There is a new SnapManager in town. This one is for Microsoft SharePoint data. See the announcementfor the [N3300 and N3600] for details.
On Jan 24, IBM signed agreements with [Ingram Micro, Tech Data, and Synnex], to distribute the N Series products and work with IBM to recruit new solution providers to the line. These three are all well-respected world-class distribution providers, so weare glad to have increased our partnership with them on this.
On Tuesday, I covered much of the Feb 26 announcements, but left the IBM System Storage DS8000 for today so that it can haveits own special focus.
Many of the enhancements relate to z/OS Global Mirror, which we formerly called eXtended Remote Copy or "XRC", not to be confused with our "regular" Global Mirror that applies to all data. For those not familiar with z/OS Global Mirror, here is how it works. The production mainframe writes updates to the DS8000, and the DS8000 keeps track of these in cache until a "reader" can pull them over to the secondary location.The "reader" is called System Data Mover (SDM) which runs in its own address space under z/OS operating system. Thanks to some work my team did several years ago, z/OS Global Mirror was able to extend beyond z/OS volumes and include Linux on System z data. Linux on System z can use a "Compatible Disk Layout" (CDL) format (now the default) that meetsall the requirements to be included in the copy session.
IBM has over 300 deployments of z/OS Global Mirror, mostly banks, brokerages and insurance companies. The feature can keep tens of thousands of volumes in one big "consistency group" and asynchronously mirror them to any distance on the planet, with the secondary copy recovery point objective (RPO) only a few seconds behind the primary.
Extended Distance FICON
Extended Distance FICON is an enhancement to the industry-standard FICON architecture (FC-SB-3) that can help avoid degradation of performance at extended distances by implementing a new protocol for "persistent" Information Unit (IU) pacing. This deals with the number of packets in flight between servers and storage separated by long distances, andcan keep a link fully utilized at 4Gpbs FICON up to 50 kilometers. This is particularly important for z/OS GlobalMirror "reader" System Data Mover (SDM). By having many "reads" in flight, this enhancementcan help reduce the need for spoofing or channel-extender equipment, or allow you to choose lower-costchannel extenders based on "frame-forwarding" technology. All of this helps reduce your total cost of ownership (TCO)for a complete end-to-end solution.
This feature will be available in March as a no-charge update to the DS8000 microcode.For more details, see the [IBM Press Release]
z/OS Global Mirror process offload to zIIP processors
To understand this one, you need to understand the different "specialty engines" available on the System z.
On distributed systems where you run a single application on a single piece of server hardware, you mightpay "per server", "per processor" or lately "per core" for dual-core and quad-core processors. Software vendors were looking for a way to charge smaller companies less, and larger companies more. However, you might end up paying the same whether you use 1GHz Intelor 4GHz Intel processor, even though the latter can do four times more work per unit time.
The mainframe has a few processors for hundreds or thousands of business applications.In the beginning, all engines on a mainframe were general-purpose "Central Processor" or CP engines. Based on theircycle rate, IBM was able to publish the number of Million Instructions per Second (MIPS) that a machine witha given number of CP engines can do. With the introduction of side co-processors, this was changed to "Millionsof Service Units" or MSU. Software licensing can charge per MSU, and this allows applications running in aslittle as one percent of a processor to get appropriately charged.
One of the first specialty engines was the IFL, the "Integrated Facility for Linux". This was a CP designatedto only run z/VM and Linux on the mainframe. You could "buy" an IFL on your mainframe much cheaper than a CP,and none of your z/OS application software would count it in the MSU calculations because z/OS can't run on theIFL. This made it very practical to run new Linux workloads.
In 2004, IBM introduced "z Application Assist Processor" (zAAP) engines to run Java, and in 2006, the "z Integrated Information Processor" (zIIP) engines to run database and background data movement activities.By not having these counted in the MSU number for business applications, it greatly reduced the cost for mainframe software.
Tuesday's announcement is that the SDM "reader" will now run in a zIIP engine, reducing the costs for applicationsthat run on that machine. Note that the CP, IFL, zAAP and zIIP engines are all identical cores. The z10 EC hasup to 64 of these (16 quad-core) and you can designate any core as any of these engine types.
Faster z/OS Global Mirror Incremental Resync
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 alsohave site "A" sending data over to size "C" using z/OS Global Mirror. This is called "Metro z/OS Global Mirror"or "MzGM" for short.
In the past, if the disk in site A failed, you would switch over to site B, and then send all the data all over again. This is because site B was not tracking what the SDM reader had or had not yet processed.With Tuesday's announcement, IBM has developed an "incremental resync" where site B figures out what theincremental delta is to connect to the z/OS Global Mirror at site "C", and this is 95% faster than sendingall the data over.
IBM Basic HyperSwap for z/OS
What if you are sending all of your data from one location to another, and one disk system fails? Do you declare a disaster and switch over entirely? With HyperSwap, you only switch over the disk systems, but leave therest of the servers alone. In the past, this involved hiring IBM Global Technology Services to implementa Geographically Dispersed Parallel Sysplex (GDPS) with software that monitors the situation and updates thez/OS operating system when a HyperSwap had occurred. All application I/O that were writing to the primary locationare automatically re-routed to the disks at the secondary location. HyperSwap can do this for all the disk systems involved,allowing applications at the primary location to continue running uninterrupted.
HyperSwap is a very popular feature, but not everyone has implemented the advanced GDPS capabilities.To address this, IBM now offers "Basic HyperSwap", which is actually going to be shipped as IBMTotalStorage Productivity Center for Replication Basic Edition for System z. This will run in a z/OSaddress space, and use either the DB2 RDBMS you already have, or provide you Apache Derby database for thosefew out there who don't have DB2 on their mainframe already.
Update: There has been some confusion on this last point, so let me explain the keydifferences between the different levels of service:
Basic HyperSwap: single-site high availability for the disk systems only
GDPS/PPRC HyperSwap Manager: single- or multi-site high availability for the disk systems, plus some entry-level disaster recovery capability
GDPS/PPRC: highly automated end-to-end disaster recovery solution for servers, storage and networks
I apologize to all my colleagues who thought I implied that Basic HyperSwap was a full replacement for the morefull-function GDPS service offerings.
Extended Address Volumes (EAV)
Up until now, the largest volume you could have was only 54 GB in size, and many customers still are using 3 GB and 9 GB volume sizes. Now, IBM will introduce 223 GB volumes. You can have any kind of data set on these volumes,but only VSAM data sets can reside on cylinders beyond the first 65,280. That is because many applications still thinkthat 65,280 is the largest cylinder number you can have.
This is important because a mainframe, or a set of mainframes clustered together, can only have about 60,000disk volumes total. The 60,000 is actually the Unit Control Block (UCB) limit, and besides disk volumes, youcan have "virtual" PAVs that serve as an alias to existing volumes to provide concurrent access.
Aside from the first item, the Extended Distance FICON, the other enhancements are "preview announcements" which means that IBM has not yet worked out the final details of price, packaging or delivery date. In many cases, the work is done, has been tested in our labs, or running beta in select client locations, but for completeness I am required to make the following disclaimer:
All statements regarding IBM's plans, directions, and intent are subject to change or withdrawal without notice. Availability, prices, ordering information, and terms and conditions will be provided when the product is announced for general availability.
Perhaps the recent financial meltdown is making storage vendors nervous.Both IBM and EMC gained market share in 3Q08, but EMC is acting strangelyat IBM's latest series of plays and announcements. Almost contradictory!
Benchmarks bad, rely on your own in-house evaluations instead
Let's start with fellow blogger Barry Burke from EMC, who offers his latest post[Benchmarketing Badly] with commentaryabout Enterprise Strategy Group's [DS5300 Lab Validation Report]. The IBM System Storage DS5300 is one of IBM's latest midrange disk systems recently announced. Take for example this excerpt from BarryB's blog post:
"I was pleasantly surprised to learn that both IBM and ESG agree with me about the relevance and importance of the Storage Performance Council benchmarks.
That is, SPC's are a meaningless tool by which to measure or compare enterprise storage arrays."
Nowhere in the ESG report says this, nor have I found any public statements from either IBM nor ESG that makes this claim. Instead, the ESG report explains that traditional benchmarks from the Storage Performance Council [SPC] focus on a single, specific workload, and ESG has chosen to complement this with a variety of other benchmarks to perform their product validation, including VMware's "VMmark", Oracle's Orion Utility, and Microsoft's JetStress.
Benchmarks provide prospective clients additional information to make purchasedecisions. IBM understands this, ESG understands this, and other well-respected companies like VMware, Oracle and Microsoft understand this. EMC is afraid that benchmarks mightencourage a client to "mistakenly" purchase a faster IBM product than a slower EMC product. Sunshine makes a great disinfectant, but EMC (and vampires) prefer their respective "prospects" remain in the dark.
Perhaps stranger still is BarryB's postscript. Here's an excerpt:
"... a customer here asked me if EMC would be willing to participate in an initiative to get multiple storage vendors to collaborate on truly representative real-world "enterprise-class" benchmarks, and I reassured him that I would personally sponsor active and objective participation in such an effort - IF he could get the others to join in with similar intent."
As I understand it, EMC was once part of the Storage Performance Council a long time ago, then chose to drop out of it. Why re-invent the wheel by creating yet another storage industry benchmark group? EMC is welcome to come back to SPC anytime! In addition to the SCP-1 and SPC-2 workloads, there is work underway for an SPC-3 benchmark. Each SPC workload provides additional insight for product comparisons to help with purchase decisions. If EMC can suggest an SPC-4 benchmark that it feels is more representative of real-world conditions, they are welcome to join the SPC party and make that a reality.
The old adage applies: ["It's better to light a candle than curse the darkness"]. EMC has been cursing the lack of what it considers to be acceptable benchmarks but has yet to offer anything more realistic or representative than SPC.What does EMC suggest you do instead? Get an evaluation box and run your own workloads and see for yourself! EMC has in the past offered evaluation units specifically for this purpose.
In-house evaluations bad, it's a trap!
Certainly, if you have the time and staff to run your own evaluation, with your own applications in your own environment, then I agree with EMC that this can provide better insight for your particular situation than standardized benchmarks.
In fact, that is exactly what IBM is doing for IBM XIV storage units, which are designed for Web 2.0 and Digital Archive workloads that current SPC benchmarks don't focus on. Fellow blogger Chuck Hollis from EMC opines in his post[Get yer free XIV!]. Here's an excerpt:
"Now that I think about it, this could get ugly. Imagine a customer who puts one on the floor to evaluate it, and -- in a moment of desperation or inattention -- puts production data on the device.
Nobody was paying attention, and there you are. Now IBM comes calling for their box back, and you've got a choice as to whether to go ahead and sign the P.O., or migrate all your data off the thing. Maybe they'll sell you an SVC to do this?
Yuck. I bet that happens more than once. And I can't believe that IBM (or the folks at XIV) aren't aware of this potentially happening."
Perhaps Chuck is speaking from experience here, as this may have happened with customers with EMC evaluation boxes, and is afraid this could happen with IBM XIV. I don't see anything unique about IBM XIV in the above concern. Typical evaluations involve copying test data onto the box, test it out with some particular application or workload, and then delete the data no longer required. Repeat as needed. Moving data off an IBM XIV is aseasy as moving data off an EMC DMX, EMC CLARiiON or EMC Celerra, and I am sure IBM wouldgladly demonstrate this on any EMC gear you now have.
Thanks to its clever RAID-X implementation, losing data on an IBM XIV is less likely thanlosing data on any RAID-5 based disk array from any storage vendor. Of course, there will always be skeptics about new technology that will want to try the box out for themselves.
If EMC thought the IBM XIV had nothing unique to offer, that its performance was just "OK",and is not as easy to manage as IBM says it is, then you would think EMC would gladly encourage such evaluations and comparisons, right?
No, I think EMC is afraid that companies will discover what they already know, that IBM has quality products that would stand a fair chance of side-by-side comparisons with their own offerings.We have enough fear, uncertainty and doubt from our current meltdown of the global financial markets, don't let EMC add any more.
Have a safe and fun Halloween! If you need to add some light to your otherwise dark surroundings, consider some of these ideas for [Jack-O-Lanterns]!