It's Tuesday, which means IBM makes its announcements. We had several for the IBM System Storage product line. Here's a quick recap.
- Disk Systems
The IBM System Storage DS3000 now offers DC power models.New DC powered models of the DS3200, DS3400, and EXP3000 are well suited for Telco industry environments, as theseare NEBS and ETSI compliant and are powered by an industry standard 48 volt DC power source.
Also, the IBM System Storage N series now supports750GB SATA drives available for the EXN1000 drawer.
- Tape Systems
IBM Virtualization Engine TS7740now supports 3-cluster grids. Unlike 3-way replication on disk mirroring, such as IBM Metro/Global Mirror for the DS8000 that enforces a primary, secondary and tertiary copy, the grid implementation of TS7740 tape virtualization allows for any-to-any mirroring. Existing standalone TS7740 clusters can be converted to grid-enabled. A "Copy Export" feature allows virtual tapes to be exported onto physical tape. And in keeping with our theme of "enabling business flexibility", performance throughput can now be purchased in 100 MB/sec increments, up to 600 MB/sec, to match your workload bandwidth requirements.
The IBM System Storage TS1120drives installed in the IBM System Storage™ TS3400 Tape Library can now be attached to System z platforms using the IBM System Storage™ TS1120 Tape Controller. Before this, the TS3400 could only be attached to UNIX, Windows and Linux systems.
The IBM System StorageTS2230 Express is offered as an external stand-alone or rack-mountable unit. This model incorporates the new LTO IBM Ultrium 3 Serial Attached SCSI (SAS) Half-High Tape Drive, and a 3 Gbps single port SAS interface for a connection to a wide spectrum of distributed system servers that support Microsoft Windows and Linux systems.
- Storage Networking
IBM has added theCisco MDS 9124 for IBM System Storageentry-level fabric switch as an Express offering and part of the IBM Express Advantage Program. Express offerings are specifically created for mid-market companies and are well suited for workgroup storage applications like e-mail serving, collaborative databases and web serving. They bring enterprise-class performance, scalability and features to small and medium-sized companies and are easy to use, highly scalable, and cost-effective.This will make it easier for IBM Business Partners to provide fabric switch connectivity for:
- Storage consolidation solutions with IBM System Storage™ DS4000 Express disk arrays, especially the DS4700 Express.
- Backup / restore solutions with IBM System Storage™ TS3000 Tape Libraries, such as the TS3200.
- Archive and Retention
Ordering large configurations of the IBM System Storage Grid Access Manager just got a lot easier.New features enable configurations greater than 500 TB to be submitted as a single order. No change in the actualproduct, just an improvement in the ordering process.
For System p and System i servers, the IBM 3996 Optical library now supports Gen 2 60GB optical cartridges. These can be read/write or WORM cartridges.
I'm off to Denver, Colorado this week. I hope it is cooler there than it is down here in Tucson, Arizona.
technorati tags: IBM, disk, system, storage, SAS, FC, DS3000, DS3200, DS3400, EXP3000, NAS, EXN1000, tape, virtualization, library, TS7740, grid, Copy Export, throughput, TS3400, TS3200, mainframe, LTO, Ultrium, Cisco, MDS, 9124, Express, Advantage, DS4000, DS4700, TS3200, GAM, Grid Archive Manager, 3996, optical, WORM, Denver, Colorado, Tucson, Arizona, announcements
Continuing this week's theme on Business Continuity, I will use this post to discuss this week'sIBM solid state disk announcement
.This new offering provides a new way to separate programs from data, to help minimizedowntime and outages normally associated with disk drive failures.
Until now, the method most people used to minimize the amount of data on internalstorage was to use disk-less servers with Boot-Over-SAN, however, not all operating systems, and not all disk systems, supported this.
In April, the BladeCenter HS21 XM blade server introduced the option to have oneIBM 4GB Flash Memory Device that used the USB2.0 protocol. The 4GB drive can be usedto boot 32-bit and 64-bit versions of Linux, such as Red Hat Enterprise Linux (RHEL) and SUSE Linux Enterprise Server (SLES)), but not Windows. Linux is incredibly small operating system. You can bootversions from a USB key/thumbdrive (64MB) or CD (700MB) image, so it makes sense that a 4GB flash drive based on USB protocol was a good fit for Linux.
Windows, however, is not supported, because of the small 4GB size and USB protocol limitations. For Windows, you would add a SAS drive, you boot from this hard drive, and use the 4GB Flash drive for data only.
So what's new this time? Here's a quick recap of July 17 announcement. For the IBM BladeCenter HS21 XM blade servers, new models of internal "disk" storage:
- Single drive model
A single 15.8GB solid-state disk drive, based on SATA protocol. In addition to theLinux operating systems mentioned above, the capacity and SATA protocols allowsyou to boot 32-bit and 64-bit versions of Windows 2003 Server R2, with plans in placeto other platforms in the future, such as VMware. I am able to run my laptop Windows with only 15GB of C: drive, separating my data to a separate D: partition, so this appears to be a reasonable size.
- Dual drive model
The dual drive fits in the space of a single 2.5-inch HDD drive bay.You can combine these in either RAID 0 or RAID 1 mode.
- RAID 0 gives you a total of 31.6GB, but is riskier. If you lose either drive,you lose all your data. Michael Horowitz of Cnet covers the risks of RAID zerohere andhere.However, if you are just storing your operating system and application, easily re-loadable from CD or DVD in the case of loss, then perhaps that is a reasonable risk/benefit trade-off.
- RAID 1 keeps the capacity at 15.8GB, but provides added protection. If you loseeither drive, the server keeps running on the surviving drive, allowing you to schedule repair actions when convenient and appropriate. This would be the configuration I would recommend for most applications.
Until recently, solid state storage was available at a price premium only. Flash prices have dropped 50% annually while capacities have doubled. This trend is expected to continue through 2009.
According to recent studies from Google and Carnegie Mellon, hard drives fail more oftenthan expected. By one account, conventional hard disk drives internal to the server account for as much as 20-50% of component replacements.IBM analysis indicates that the replacement rate of a solid state drive on a typical blade server configuration is only about 1% per year, vs. 3% or more mentionedin the these studies for traditional disk drives.
Flash drives use non-volatile memory instead of moving parts, so less likely to break down during high external environmental stress conditions, like vibration and shock, or extreme temperature ranges (-0C° to +70°C) that would make traditional hard disks prone to failure.This is especially important for our telecommunications clients, who are always looking for solutions that are NEBS Level 3 compliant.
Last year, I mentioned that flash drives could provide only a limited number of write and erase cycles, but today's new advances in wear-leveling algorithms have nearly eliminated this limitation.
As with any SATA drive, performance depends on workload.Solid state drives perform best as OS boot devices, taking only a few secondslonger to boot an OS than from a traditional 73GB SAS drive. Flash drives also excel in applications featuring random read workloads, such as web servers. For random and sequential write workloads, use SAS drives instead for higher levels of performance.
Part of IBM's Project Big Green, these flash drives are very energy efficient. Thanks to sophisticated power management software, the power requirement of the solid state drive can be 95 percent better than that of a traditional 73GB hard disk drive. These 15.8GB drives use only 2W per drive versus as much as 10W per 2.5” hard drive and 16W per 3.5” hard drive. The resulting power savings can be up to 1,512 watts per server rack, with 50% heat reduction.
So, even though this is not part of the System Storage product line, I am very excitedfor IBM. To find out if this will work in your environment, go to the IBM Server Provenwebsite that lists compatability with hardware, applications and middleware, or review the latest Configuration and Options Guide (COG).
technorati tags: IBM, Business, Continuity, solid, state, flash, disk, drive, announcement, blade, server, BladeCenter, H21, XM, 4GB, Flash, Memory, Device, USB2.0, Linux, RedHat, RHEL, Novell, SUSE, SLES, Windows, Project, Big Green, SATA, SAS, energy, efficient, efficiency, performance, NEBS, telecommunications, boot-over-SAN, Google, Carnegie Mellon, study, Vmware
For those in the US, a comedian named Carlos Mencia has a great TV show, Mind of Mencia
and one of my favorite segments is "Why the @#$% is this news!" where he goes about showingblatantly obvious things that were reported in various channels.
So, when I saw that IBM once again, for the third year in a row, has the fastest disk system,the IBM System Storage SAN Volume Controller (SVC), based on widely-accepted industry benchmarksrepresenting typical business workloads, I thought, "Do I really want to blog about this,and sound like a broken record, repeating my various statements of the past of how great SVC is?" It's like reminding people that IBM hashad the most US patents than any other company, every year, for the past 14 years.
(Last year, I received comments fromWoody Hutsell, VP of Texas Memory Systems,because I pointed out that their "World's Fastest Storage"® cache-only system, was not as fast as IBM's SVC.You can ready my opinions, and the various comments that ensued, hereand here. )
That all changed when EMC uber-blogger Chuck Hollis forgot his own Lessons in Marketingwhen heposted his rantDoes Anyone Take The SPC Seriously?That's like asking "Does anyone take book and movie reviews seriously?" Of course they do!In fact, if a movie doesn't make a big deal of its "Two thumbs up!" rating, you know it did not sitwill with the reviewers. It's even more critical for books. I guess this latest news from SPC reallygot under EMC's skin.
For medium and large size businesses, storage is expensive, and customers want to do as much research as possible ahead of time to make informed decisions. A lot of money is at stake, and often, once you choose a product, you are stuckwith that vendor for many years to come, sometimes paying software renewals after only 90 days, and hardware maintenance renewals after only a year when the warranty runs out.
Customers shopping for storage like the idea of a standardized test that is representative, so they can compare one vendor's claims with another. The Storage Performance Council (SPC), much like the Transaction Processing Performance Council (TPC-C) for servers, requires full disclosure of the test environment so people can see what was measured and make their own judgement on whether or not it reflects their workloads. Chuck pours scorn on SPC but I think we should point to TPC-C as a great success story and ask why he thinks the same can't happen for storage? Server performance is also a complicatedsubject, but people compare TPC-C and TPC-H benchmarks all the time.
Note: This blog post has been updated. I am retracting comments that were unfair generalizations. The next two paragraphs are different than originally posted.
Chuck states that "Anyone is free, however, to download the SPC code, lash it up to their CLARiiON, and have at it." I encourage every customer to do this with whatever disk systems they already have installed. Judge for yourself how each benchmark compares to your experience with your application workload, and consider publishing the results for the benefit of others, or at least send me the results, so that I can understand better all of these"use cases" that Chuck talks about so often. I agree that real-world performance measurements using real applications and real data are always going to be more accurate and more relevant to that particular customer. Unfortunately, there are little or no such results made public. They are noticeably absent. With thousands of customers running with storage from all the major storage vendors, as well as storage from smaller start-up companies, I would expect more performance comparison data to be readily available.
In my opinion, customers would benefit by seeing the performance results obtained by others. SPC benchmarks help to fill this void, to provide customers who have not yet purchased the equipment, and are looking for guidance of which vendors to work with, and which products to put into their consideration set.
Truth is, benchmarks are just one of the many ways to evaluate storage vendors and their products. There are also customer references, industry awards, and corporate statements of a company's financial health, strategy and vision.Like anything, it is information to weigh against other factors when making expensive decisions. And I am sure the SPC would be glad to hear of any suggestions for a third SPC-3 benchmark, if the first two don't provide you enough guidance.
So, if you are not delighted with the performance you are getting from your storage now, or would benefit by having even faster I/O, consider improving its performance by adding SAN Volume Controller. SVC is like salt or soy sauce, it makes everything taste better. IBM would be glad to help you with a try-and-buy or proof-of-concept approach, and even help you compare the performance, before and after, with whatever gear you have now. You might just be surprised how much better life is with SVC. And if, for some reason, the performance boost you experience for your unique workload is only 10-30% better with SVC, you are free to tell the world about your disappointment.
technorati tags: Carlos Mencia, Mind of Mencia, IBM, system, storage, SVC, SAN Volume Controller, Storage Performance Council,SPC, benchmarks, Texas Memory Systems, Woody Hutsell, EMC, Chuck Hollis, movie, book, reviews, awards, salt, soy sauce
Continuing this week's theme on Business Continuity, I thought I would explore more on the identification of scenarios to help drive appropriate planning. As I mentioned in my last post
, this should be done first.
A recent post in Anecdote talks about the long list of cognitive biases which affect business decision making. This list is a good explanation of why so many people have a difficult time identifying appropriate recovery scenarios as the basis for Business Continuity planning. Their "cognitive biases" get in the way.
Again, using my IBM Thinkpad T60 laptop as an example, here are a variety of different scenarios:
- Corrupted File System
Some file systems are more fragile than others. If your NTFS file system gets corrupted, you might be able to run
CHKDSK C: /F but this just puts damaged blocks into dummy files, it doesn't really repair your files back to their pre-damage level.All kinds of things can damage the file system, including viruses, software defects, and user error.
I keep my programs and data in separate file systems. C: has my Windows operating system and applications, and D: holds my pure data. If one file system is corrupted, the other one might be in tact, mitigating the risk.
- Hard Disk Crash
Hopefully, you will have temporary read/write errors to provide warning prior to a complete failure. In theory, if I kept a spare hard disk in my laptop bag, I could swap out the bad drive with the good drive. I don't have that. The three times that I have had a disk failure all occurred while I was in Tucson.
Instead, I keep the few files I need for my trip on a separate USB key, and carry bootable Live CD, which allows you to boot entirely from CDrom drive, either to run applications, or perform rescue operations.
The latest one that I am trying out is Ubuntu Linux, which has OpenOffice 2.2 that can read/write PowerPoint, Word, and Excel spreadsheets; Firefox web browser; Gimp graphics software; and a variety of other applications, all in a 700MB CDrom image. I even have been able to get Wireless (Wi-Fi) working with it, and the process to create your own customized Live CD with the your own application packages is fairly straightforward. Combined with a writeable USB key, you can actually get work done this way. Special thanks to IBM blogger Bob Sutor for pointing me to this.
(If you have a DVD-RAM drive, there are bigger Live CDs from SUSE and RedHat Fedora that provide even more applications)
- Laptop Shell Failure
This might catch some people by surprise. I have had the keyboard, LCD screen, or some essential port/plug fail on my laptop. The disk drive and CDrom drive work fine, but unless you have another "laptop" to stick them into, they don't help you recover. This can also happen if the motherboard fails, or the battery is unable to hold a charge.
IBM provides a 24-hour turn around fix. Basically, IBM sends me a laptop shell, no drive, no CDrom, with instructions to move the disk drive and CDrom drive from your broken shell, to the new shell, then send the bad shell back in the same shipping box.
Here, again, I am thankful that I keep my key files on an USB key. Often I travel with other IBMers, and can borrow their laptop to make presentations, check my e-mail, or other work, until I can get my replacement shell. In you are travelling outside the US, you might be able to move your disk drive into a colleague's laptop, access the data, copy it to your USB key or burn a copy on CD or DVD.
In a data center, many outages are really "failures to access data", but the data is safe. For example, power outages, network outages, and so on, can prevent people from using their IT systems, but the data is safe when these are re-established.
- Temporary Separation
At times, I have been temporarily separated from my laptop. Three examples:
- A higher level executive had technical difficulties with his laptop, and usurped mine instead.
- A colleague forgot his power supply for his laptop, and borrowed my laptop instead. (I wish there were a standard for laptop power plug connectors)
- Customs agents confiscate your laptop, give you a receipt, and eventually you get it back.
In all cases, I was glad that no "recovery" was required, and that the few files I needed were on my USB key. A few times, I was able to get by on the machines available at the nearest Internet Cafe, in the meantime.
With some imagination, you can recognize that this scenario is similar to the previous one for laptop shell failure.Here is a good example that you can identify different scenarios, and then later discover they have similar properties in terms of recovery, and can be treated as one.
- Permanent Separation
Laptops are stolen every day. Luckily, I've only had this happen twice to me in my career at IBM, and I managed to get a replacement soon enough. The key lesson here is to keep your USB key and recovery media in separate luggage.I know it is more convenient to keep all computer-related stuff in one place, but a thief is going to take your whole laptop bag, to make sure that all cables and power supplies are included, and is not going to leave anything behind. That would just slow them down.
In each case, some brainstorming, or personal experience, can help identify scenarios, identify what makes them unique from a recovery perspective, and plan accordingly. If you looking to create or upgrade your Business Continuity plan, give IBM a call, we can help!
technorati tags: IBM, Business, Continuity, plan, plans, planning, Thinkpad, T60, laptop, NTFS, CHKDSK, hard disk crash, USB, key, Live, CD, LiveCD, DVD, Ubuntu, Linux, SUSE, RedHat, Fedora, shell, failure
Continuing our exploration this week into the performance of disk systems, today I will cover the metrics to measure performance. Why do people have metrics?
- Help provide guidance in decision making prior to purchase
- Help manage your current environment
- Help drive changes
Several bloggers suggested that perhaps an analogy to vehicles would be reasonable, given that cars and trucks are expensive pieces of engineering equipment, and people make purchase decisions between different makes and models.
In the United States, the Environmental Protection Agency (EPA) government entity is responsible for measuringfuel economy of vehicles using the metric Miles Per Gallon (mpg).Specifically, these are U.S. miles (not nautical miles) and U.S. gallons, not imperial gallons. It is importantwhen defining metrics that you are precise on the units involved.
Since nearly all vehicles are driven by gallons of gasoline, and travel miles of distance, this is a great metric to use for comparing all kinds of vehicles, including motorcycles, cars, trucks and airplanes. The EPA has a fuel economy website to help people make these comparisons.Manufacturers are required by law to post their vehicles' fuel-economy ratings, as certified by the federal Environmental Protection Agency (EPA), on the window stickers of most every new vehicle sold in the U.S. -- vehicles that have gross-vehicle-weight ratings over 8,500 pounds are the exception.
What about storage performance? What could we use as the "MPG"-like metric that would allow you to compare different makes and models of storage?
The two most commonly used are I/O requests per second (IOPS) and Megabytes transferred per second (MB/s). To understand the difference in each one, let's go back to our analogy from yesterday's post.
(A woman calls the local public library. She picks up the phone, and dials the phone number of the one down the street. A man working at the library hears the phone ring, answers it with "Welcome to the Public Library! How can I help you?" She asks "What is the capital city of Ethiopia?" He replies "Addis Ababa" and hangs up. Satisfied with this response, she hangs up. In this example, the query for information was the I/O request, initiated by the lady, to the public library target)
In this example, it might have only taken 1 second to actually provide the answer, but it might have taken 10-30 seconds to pick up the phone, hear the request, respond, and then hang up the phone. If one person is able to do this in 10 seconds, on average, then he can handle 360 questions per hour. If another person takes 30 seconds, then only 120 questions per hour. Many business applications read or write less than 4KB of information per I/O request, and as such the dominant factor is not the amount of time to transfer the data, but how quickly the disk system can respond to each request. IOPS is very much like counting "Questions handled per hour" at the public library. To be more specific on units, we may specify the specific block size of the request, say 512 bytes or 4096 bytes, to make comparisons consistent.
Now suppose that instead of asking for something with a short answer, you ask the public library to read you the article from a magazine, identify all the movies and show times of a local theatre, or recite a work from Shakespeare. In this case, the time it took to pick up the phone and respond is very small compared to the time it takes to deliverthe information, and could be measured instead in words per minute. Some employees of the library may be faster talkers, having perhaps worked in auction houses in a prior job, and can deliver more words per minute than other employees. MB/s is very much like counting "Spoken words per minute" at the public library. To be more specific on units, we may request a specific amount of information, say the words contained in "Romeo and Juliet", to make comparisons consistent.
Now that we understand the metrics involved, tomorrow we can discuss how to use these in the measurement process.
technorati tags: IBM, disk, systems, EPA, MPG, mileage, fuel, economy, IOPS, MB/s, Shakespeare, vehicles, cars, trucks, motorcycles, airplanes