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Tony Pearson is a Master Inventor, Senior IT Architect and Event Content Manager for [IBM Systems for IBM Systems Technical University] events. With over 30 years with IBM Systems, Tony is frequent traveler, speaking to clients at events throughout the world.
Lloyd Dean is an IBM Senior Certified Executive IT Architect in Infrastructure Architecture. Lloyd has held numerous senior technical roles at IBM during his 19 plus years at IBM. Lloyd most recently has been leading efforts across the Communication/CSI Market as a senior Storage Solution Architect/CTS covering the Kansas City territory. In prior years Lloyd supported the industry accounts as a Storage Solution architect and prior to that as a Storage Software Solutions specialist during his time in the ATS organization.
Lloyd currently supports North America storage sales teams in his Storage Software Solution Architecture SME role in the Washington Systems Center team. His current focus is with IBM Cloud Private and he will be delivering and supporting sessions at Think2019, and Storage Technical University on the Value of IBM storage in this high value IBM solution a part of the IBM Cloud strategy. Lloyd maintains a Subject Matter Expert status across the IBM Spectrum Storage Software solutions. You can follow Lloyd on Twitter @ldean0558 and LinkedIn Lloyd Dean.
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In North America, today marks the start of the "Give 1 Get 1" program.
Children using the XO laptop
I first learned from this when I was reading about Timothy Ferriss' [LitLiberation project] on his [Four Hour Work Week] blog, and was surfing around for related ideas, and chanced upon this. I registered for a reminder, and it came today(the reminder, not the laptop itself).
Here's how the program works. You give $399 US dollars to the "One Laptop per Child" (OLPC)[laptop.org] organization for two laptops: One goes to a deserving child ina developing country, the second goes to you, for your own child, or to donate to a localcharity that helps children. This counts as a $199 purchase plus a $200 tax-deductible donation.For Americans, this is a [US 501(c)(3)] donation, and for Canadians and Mexicans, take advantage of the low-value of the US dollar!
If your employer matches donations, like IBM does, get them to match the $200donation for a third laptop, which goes to another child in a developing country. As for shipping, you pay only for the shipping of the one to you, each receiving country covers their own shipping. In my case, the shipping was another $24 US dollars for Arizona.No guarantees that it will arrive in time for the holidays this December, but it might.
To sweeten the deal, T-mobile throws in a year's worth of "Wi-Fi Hot Spot"that you can use for yourself, either with the XO laptop itself, or your regular laptop, iPhone, or otherWi-Fi enabled handheld device.
National Public Radio did a story last week on this:[The $100 Laptop Heads for Uganda]where they interview actor [Masi Oka], best known from the TV show ["Heroes"], who has agreed to be their spokesman.At the risk of sounding like their other spokesman, I thought I would cover the technology itself, inside the XO,and how this laptop represents IBM's concept of "Innovation that matters"!
The project was started by [Nicholas Negroponte] from [MIT University] as the "$100 laptop project". Once the final designwas worked out, it turns out it costs $188 US dollars to make, so they rounded it up to $200. This is stillan impressive price, and requires that hundreds of thousands of them be manufactured to justify ramping upthe assembly line.
Two of IBM's technology partners are behind this project. First is Advanced Micro Devices (AMD) that providesthe 433Mhz x86 processor, which is 75 percent slower than Thinkpad T60. Second is Red Hat,as this runs lean Fedora 6 version of Linux. Obviously, you couldn't have Microsoft Windows or Apple OS X, as both require significantly more resources.
The laptop is "child size", and would be considered in the [subnotebook] category. At 10" x 9" x 1.25", it is about the size of class textbook,can be carried easily in a child's backpack, or carried by itself with the integrated handle. When closed, it is sealedenough to be protected when carried in rain or dust storms. It weighs about 3.5 pounds, less than the 5.2 pounds of myThinkpad T60.
The XO is "green", not just in color, but also in energy consumption.This laptop can be powered by AC, or human power hand-crank, with workin place to get options for car-battery or solar power charging. Compared to the 20W normally consumed bytraditional laptops, the XO consumes 90 percent less, running at 2W or less. To accomplish this, there is no spinning disk inside. Instead, a 1GB FLASH drive holds 700MB of Linux, and gives you 300MB to hold your files. There isa slot for an MMC/SD flash card, and three USB 2.0 ports to connect to USB keys, printers or other remote I/O peripherals.
The XO flips around into three positions:
Standard laptop position has screen and keyboard. The water-tight keyboard comes in ten languages:International/English, Thai, Arabic, Spanish, Portuguese, West African, Urdu, Mongolian, Cyrillic, and Amharic.(I learned some Amharic, having lived five years with Ethiopians.)There does not appear be a VGA port, so don't be thinking this could be used as an alternative to project Powerpoint presentations onto a big screen.
Built-in 640x480 webcam, microphone and speakers allow the XO to be used as a communication device. Voice-over-IP (VOIP) client software, similar to Skype or [IBM Lotus Sametime], is pre-installed for this purpose.
The basic built-in communication are 802.1g (54Mbs) that you can use to surf the web usingthe Wi-Fi at your local Starbucks; and 802.1s which forms a "mesh network" with other XO laptops, and can surf theweb finding the one laptop nearby that is connected to the internet to share bandwidth. This eliminates the need to build a separate Wi-Fi hub at the school. There are USB-to-Ethernet and USB-to-Cellular converters, so that might be an alternative option.
Flipped vertically, the device can be read like a book.The screen can be changed between full-color and black-white, 200 dpi, with decent 1200x900 pixel resolution. The full-color is back-lit, and can be read in low-lighting. The black-white is not back-lit, consumes much less power, andcan be read in bright sunlight. In that regards, it is comparable to other [e-book devices], like a Cybook or Sony Reader.
Software includes a web-browser, document reader, word processor and RSS feed reader to read blogs.The OLPC identifies all of the software, libraries and interfaces they use, so that anyone that wants to developchildren software for this platform can do so.
With the keyboard flipped back, the 6" x 4.5" screen has directional controls and X/Y/A/B buttons to run games. This would make it comparable to a Nintendo DS or Playstation Portable (PSP). Again, the choice between back-lit color,or sunlight black-white screen modes apply. Some games are pre-installed.
So for $399, you could buy a Wi-Fi enabled[16GB iPod Touch] for yourself, which does much the same thing, or you can make a difference in the world.I made my donation this morning, and suggest you--my dear readers in the US, Canada and Mexico--consider doing the same.Go to [www.laptopgiving.org] for details.
Miles per Gallon measures an effeciency ratio (amount of work done with a fixed amount of energy), not a speed ratio (distance traveled in a unit of time).
Given that IOPs and MB/s are the unit of "work" a storage array does, wouldn't the MPG equivalent for storage be more like IOPs per Watt or MB/s per Watt? Or maybe just simply Megabytes Stored per Watt (a typical "green" measurement)?
You appear to be intentionally avoiding the comparison of I/Os per Second and Megabytes per Second to Miles Per Hour?
May I ask why?
This is a fair question, Barry, so I will try to address it here.
It was not a typo, I did mean MPG (miles per gallon) and not MPH (miles per hour). It is always challenging to find an analogy that everyone can relate to explain concepts in Information Technology that might be harder to grasp. I chose MPG because it was closely related to IOPS and MB/s in four ways:
MPG applies to all instances of a particular make and model. Before Henry Ford and the assembly line, cars were made one at a time, by a small team of craftsmen, and so there could be variety from one instance to another. Today, vehicles and storage systems are mass-produced in a manner that provides consistent quality. You can test one vehicle, and safely assume that all similar instances of the same make and model will have the similar mileage. The same is true for disk systems, test one disk system and you can assume that all others of the same make and model will have similar performance.
MPG has a standardized measurement benchmark that is publicly available. The US Environmental Protection Agency (EPA) is an easy analogy for the Storage Performance Council, providing the results of various offerings to chose from.
MPG has usage-specific benchmarks to reflect real-world conditions.The EPA offers City MPG for the type of driving you do to get to work, and Highway MPG, to reflect the type ofdriving on a cross-country trip. These serve as a direct analogy to SPC having SPC-1 for Online transaction processing (OLTP) and SPC-2 for large file transfers, database queries and video streaming.
MPG can be used for cost/benefit analysis.For example, one could estimate the amount of business value (miles travelled) for the amount of dollar investment (cost to purchase gallons of gasoline, at an assumed gas price). The EPA does this as part of their analysis. This is similar to the way IOPS and MB/s can be divided by the cost of the storage system being tested on SPC benchmark results. The business value of IOPS or MB/s depends on the application, but could relate to the number of transactions processed per hour, the number of music downloads per hour, or number of customer queries handled per hour, all of which can be assigned a specific dollar amount for analysis.
It seemed that if I was going to explain why standardized benchmarks were relevant, I should find an analogy that has similar features to compare to. I thought about MPH, since it is based on time units like IOPS and MB/s, butdecided against it based on an earlier comment you made, Barry, about NASCAR:
Let's imagine that a Dodge Charger wins the overwhelming majority of NASCAR races. Would that prove that a stock Charger is the best car for driving to work, or for a cross-country trip?
Your comparison, Barry, to car-racing brings up three reasons why I felt MPH is a bad metric to use for an analogy:
Increasing MPH, and driving anywhere near the maximum rated MPH for a vehicle, can be reckless and dangerous,risking loss of human life and property damage. Even professional race car drivers will agree there are dangers involved. By contrast, processing I/O requests at maximum speed poses no additional risk to the data, nor possibledamage to any of the IT equipment involved.
While most vehicles have top speeds in excess of 100 miles per hour, most Federal, State and Local speed limits prevent anyone from taking advantage of those maximums. Race-car drivers in NASCAR may be able to take advantage of maximum MPH of a vehicle, the rest of us can't. The government limits speed of vehicles precisely because of the dangers mentioned in the previous bullet. In contrast, processing I/O requests at faster speeds poses no such dangers, so the government poses no limits.
Neither IOPS nor MB/s match MPH exactly.Earlier this week,I related IOPS to "Questions handled per hour" at the local public library, and MB/s to "Spoken words per minute" in those replies. If I tried to find a metric based on unit type to match the "per second" in IOPS and MB/s, then I would need to find a unit that equated to "I/O requests" or "MB transferred" rather than something related to "distance travelled".
In terms of time-based units, the closest I could come up with for IOPS was acceleration rate of zero-to-sixty MPH in a certain number of seconds. Speeding up to 60MPH, then slamming the breaks, and then back up to 60MPH, start-stop, start-stop, and so on, would reflect what IOPS is doing on a requestby request basis, but nobody drives like this (except maybe the taxi cab drivers here in Malaysia!)
Since vehicles are limited to speed limits in normal road conditions, the closest I could come up with for MB/s would be "passenger-miles per hour", such that high-occupancy vehicles like school buses could deliver more passengers than low-occupancy vehicles with only a few passengers.
Neither start-stops nor passenger-miles per hour have standardized benchmarks, so they don't work well for comparisonbetween vehicles.If you or anyone can come up with a metric that will help explain the relevance of standardized benchmarks better than the MPG that I already used, I would be interested in it.
You also mention, Barry, the term "efficiency" but mileage is about "fuel economy".Wikipedia is quick to point out that the fuel efficiency of petroleum engines has improved markedly in recent decades, this does not necessarily translate into fuel economy of cars. The same can be said about the performance of internal bandwidth ofthe backplane between controllers and faster HDD does not necessarily translate to external performance of the disk system as a whole. You correctly point this out in your blog about the DMX-4:
Complementing the 4Gb FC and FICON front-end support added to the DMX-3 at the end of 2006, the new 4Gb back-end allows the DMX-4 to support the latest in 4Gb FC disk drives.
You may have noticed that there weren't any specific performance claims attributed to the new 4Gb FC back-end. This wasn't an oversight, it is in fact intentional. The reality is that when it comes to massive-cache storage architectures, there really isn't that much of a difference between 2Gb/s transfer speeds and 4Gb/s.
Oh, and yes, it's true - the DMX-4 is not the first high-end storage array to ship a 4Gb/s FC back-end. The USP-V, announced way back in May, has that honor (but only if it meets the promised first shipments in July 2007). DMX-4 will be in August '07, so I guess that leaves the DS8000 a distant 3rd.
This also explains why the IBM DS8000, with its clever "Adaptive Replacement Cache" algorithm, has such highSPC-1 benchmarks despite the fact that it still uses 2Gbps drives inside. Given that it doesn't matter between2Gbps and 4Gbps on the back-end, why would it matter which vendor came first, second or third, and why call it a "distant 3rd" for IBM? How soon would IBM need to announce similar back-end support for it to be a "close 3rd" in your mind?
I'll wrap up with you're excellent comment that Watts per GB is a typical "green" metric. I strongly support the whole"green initiative" and I used "Watts per GB" last month to explain about how tape is less energy-consumptive than paper.I see on your blog you have used it yourself here:
The DMX-3 requires less Watts/GB in an apples-to-apples comparison of capacity and ports against both the USP and the DS8000, using the same exact disk drives
It is not clear if "requires less" means "slightly less" or "substantially less" in this context, and have no facts from my own folks within IBM to confirm or deny it. Given that tape is orders of magnitude less energy-consumptive than anything EMC manufacturers today, the point is probably moot.
I find it refreshing, nonetheless, to have agreed-upon "energy consumption" metrics to make such apples-to-apples comparisons between products from different storage vendors. This is exactly what customers want to do with performance as well, without necessarily having to run their own benchmarks or work with specific storage vendors. Of course, Watts/GB consumption varies by workload, so to make such comparisons truly apples-to-apples, you would need to run the same workload against both systems. Why not use the SPC-1 or SPC-2 benchmarks to measure the Watts/GB consumption? That way, EMC can publish the DMX performance numbers at the same time as the energy consumption numbers, and then HDS can follow suit for its USP-V.
I'm on my way back to the USA soon, but wanted to post this now so I can relax on the plane.
Wrapping up this week's exploration on disk system performance, today I willcover the Storage Performance Council (SPC) benchmarks, and why I feel they are relevant to help customers make purchase decisions. This all started to address a comment from EMC blogger Chuck Hollis, who expressed his disappointment in IBM as follows:
You've made representations that SPC testing is somehow relevant to customers' environments, but offered nothing more than platitudes in support of that statement.
Apparently, while everyone else in the blogosphere merely states their opinions and moves on,IBM is held to a higher standard. Fair enough, we're used to that.Let's recap what we covered so far this week:
Monday, I explained how seemingly simple questions like "Which is the tallestbuilding?" or "Which is the fastest disk system?" can be steeped in controversy.
Tuesday, I explored what constitutes a disk system. While there are special storage systemsthat include HDD that offer tape-emulation, file-oriented access, or non-erasable non-rewriteable protection,it is difficult to get apples-to-apples comparisions with storage systems that don't offer these special features.I focused on the majority of general-purpose disk systems, those that are block-oriented, direct-access.
Today, I will explore ways to apply these metrics to measure and compare storageperformance.
Let's take, for example, an IBM System Storage DS8000 disk system. This has a controller thatsupports various RAID configurations, cache memory, and HDD inside one or more frames.Engineers who are testing individual components of this system might run specifictypes of I/O requests to test out the performance or validate certain processing.
100% read-hit, this means that all the I/O requests are to read data expectedto be in the cache.
100% read-miss, this means that all the I/O requests are to read data expectedNOT to be in the cache, and must go fetch the data from HDD.
100% write-hit, this means that all the I/O requests are to write data into cache.
100% write-miss, this means that all the I/O requests are to bypass the cache,and are immediately de-staged to HDD. Depending on the RAID configuration, this can result in actually reading or writing several blocks of data on HDD to satisfy thisI/O request.
Known affectionately in the industry as the "four corners" test, because you can show them on a box, with writes on the left, reads on the right,hits on the top, and misses on the bottom.Engineers are proud of these results, but these workloads do notreflect any practical production workload. At best, since all I/O requests are oneof these four types, the four corners provide an expectation range from the worst performance (most often write-missin the lower left corner)and the best performance (most often read-hit in the upper right corner) you might get with a real workload.
To understand what is needed to design a test that is more reflective of real business conditions,let's go back to yesterday's discussion of fuel economy of vehicles, with mileage measured in miles per gallon.The How Stuff Works websiteoffers the following description for the two measurements taken by the EPA:
The "city" program is designed to replicate an urban rush-hour driving experience in which the vehicle is started with the engine cold and is driven in stop-and-go traffic with frequent idling. The car or truck is driven for 11 miles and makes 23 stops over the course of 31 minutes, with an average speed of 20 mph and a top speed of 56 mph.
The "highway" program, on the other hand, is created to emulate rural and interstate freeway driving with a warmed-up engine, making no stops (both of which ensure maximum fuel economy). The vehicle is driven for 10 miles over a period of 12.5 minutes with an average speed of 48 mph and a top speed of 60 mph.
Why two different measurements? Not everyone drives in a city in stop-and-go traffic. Having only one measurement may not reflect the reality that you may travel long distances on the highway. Offering both city and highway measurements allows the consumers to decide which metric relates closer to their actual usage.
Should you expect your actual mileage to be the exact same as the standardized test?Of course not. Nobody drives exactly 11 miles in the city every morning with 23 stops along the way,or 10 miles on the highway at the exact speeds listed.The EPA's famous phrase "your mileage may vary" has been quickly adopted into popular culture's lexicon. All kinds of factors, like weather, distance, anddriving style can cause people to get better or worse mileage than thestandardized tests would estimate.
Want more accurate results that reflect your driving pattern, in specific conditions that you are most likely to drive in? You could rentdifferent vehicles for a week and drive them around yourself, keeping track of whereyou go, and how fast you drove, and how many gallons of gas you purchased, so thatyou can then repeat the process with another rental, and so on, and then use yourown findings to base your comparisons. Perhaps you find that your results are always20% worse than EPA estimates when you drive in the city, and 10% worse when you driveon the highway. Perhaps you have many mountains and hills where you drive, you drive too fast, you run the Air Conditioner too cold, or whatever.
If you did this with five or more vehicles, and ranked them best to worstfrom your own findings, and also ranked them best to worst based on the standardizedresults from the EPA, you likely will find the order to be the same. The vehiclewith the best standardized result will likely also have the best result from your ownexperience with the rental cars. The vehicle with the worst standardized result willlikely match the worst result from your rental cars.
(This will be one of my main points, that standardized estimates don't have to be accurate to beuseful in making comparisons. The comparisons and decisions you would make with estimatesare the same as you would have made with actual results, or customized estimates based on current workloads. Because the rankings are in the same order, they are relevant and useful for making decisions based on those comparisons.)
Most people shopping around for a new vehicle do not have the time or patience to do this with rental cars. Theycan use the EPA-certified standardized results to make a "ball-park" estimate on how much they will spendin gasoline per year, decide only on cars that might go a certain distancebetween two cities on a single tank of gas, or merely to provide ranking of thevehicles being considered. While mileage may not be the only metric used in making a purchase decision, it can certainly be used to help reduce your consideration setand factor in with other attributes, like number of cup-holders, or leather seats.
In this regard, the Storage Performance Council has developed two benchmarks that attempt to reflect normal business usage, similar to "City" and "Highway" driving measurements.
SPC-1 consists of a single workload designed to demonstrate the performance of a storage subsystem while performing the typical functions of business critical applications. Those applications are characterized by predominately random I/O operations and require both queries as well as update operations. Examples of those types of applications include OLTP, database operations, and mail server implementations.
SPC-2 consists of three distinct workloads designed to demonstrate the performance of a storage subsystem during the execution of business critical applications that require the large-scale, sequential movement of data. Those applications are characterized predominately by large I/Os organized into one or more concurrent sequential patterns. A description of each of the three SPC-2 workloads is listed below as well as examples of applications characterized by each workload.
Large File Processing: Applications in a wide range of fields, which require simple sequential process of one or more large files such as scientific computing and large-scale financial processing.
Large Database Queries: Applications that involve scans or joins of large relational tables, such as those performed for data mining or business intelligence.
Video on Demand: Applications that provide individualized video entertainment to a community of subscribers by drawing from a digital film library.
The SPC-2 benchmark was added when people suggested that not everyone runs OLTP anddatabase transactional update workloads, just as the "Highway" measurement was addedto address the fact that not everyone drives in the City.
If you are one of the customers out there willing to spend the time and resources to do your own performance benchmarking, either at your own data center, or with theassistance of a storage provider, I suspect most, if not all, the major vendors(including IBM, EMC and others), and perhaps even some of the smaller start-ups, would be glad to work with you.
If you want to gather performance data of your actual workloads, and use this to estimate how your performance might be with a new or different storage configuration, IBMhas tools to make these estimates, and I suspect (again) that most, if not all, of theother storage vendors have developed similar tools.
For the rest of you who are just looking to decide which storage vendors to invite on your next RFP, and which products you might like to investigate that matchthe level of performance you need for your next project or application deployment,than the SPC benchmarks might help you with this decision. If performance is importantto you, factor these benchmark comparisons with the rest of the attributes you arelooking for in a storage vendor and a storage system.
In my opinion, I feel that for some people, the SPC benchmarks provide some value in this decision making process. They are proportionally correct, in that even ifyour workload gets only a portion of the SPC estimate, that storage systems withfaster benchmarks will provide you better performance than storage systems with lower benchmark results. That is why I feel they can be relevant in makingvalid comparisons for purchase decisions.
Hopefully, I have provided enough "food for thought"on this subject to support why IBM participates in the Storage Performance Council, why the performance of the SAN Volume Controller can be compared to the performanceof other disk systems, and why we at IBM are proud of the recent benchmark results in our recent press release.
Well, this week I am in Maryland, just outside of Washington DC. It's a bit cold here.
Robin Harris over at StorageMojo put out this Open Letter to Seagate, Hitachi GST, EMC, HP, NetApp, IBM and Sun about the results of two academic papers, one from Google, and another from Carnegie Mellon University (CMU). The papers imply that the disk drive module (DDM) manufacturers have perhaps misrepresented their reliability estimates, and asks major vendors to respond. So far, NetAppand EMC have responded.
I will not bother to re-iterate or repeat what others have said already, but make just a few points. Robin, you are free to consider this "my" official response if you like to post it on your blog, or point to mine, whatever is easier for you. Given that IBM no longer manufacturers the DDMs we use inside our disk systems, there may not be any reason for a more formal response.
Coke and Pepsi buy sugar, Nutrasweet and Splenda from the same sources
Somehow, this doesn't surprise anyone. Coke and Pepsi don't own their own sugar cane fields, and even their bottlers are separate companies. Their job is to assemble the components using super-secret recipes to make something that tastes good.
IBM, EMC and NetApp don't make DDMs that are mentioned in either academic study. Different IBM storage systems uses one or more of the following DDM suppliers:
Seagate (including Maxstor they acquired)
Hitachi Global Storage Technologies, HGST (former IBM division sold off to Hitachi)
In the past, corporations like IBM was very "vertically-integrated", making every component of every system delivered.IBM was the first to bring disk systems to market, and led the major enhancements that exist in nearly all disk drives manufactured today. Today, however, our value-add is to take standard components, and use our super-secret recipe to make something that provides unique value to the marketplace. Not surprisingly, EMC, HP, Sun and NetApp also don't make their own DDMs. Hitachi is perhaps the last major disk systems vendor that also has a DDM manufacturing division.
So, my point is that disk systems are the next layer up. Everyone knows that individual components fail. Unlike CPUs or Memory, disks actually have moving parts, so you would expect them to fail more often compared to just "chips".
If you don't feel the MTBF or AFR estimates posted by these suppliers are valid, go after them, not the disk systems vendors that use their supplies. While IBM does qualify DDM suppliers for each purpose, we are basically purchasing them from the same major vendors as all of our competitors. I suspect you won't get much more than the responses you posted from Seagate and HGST.
American car owners replace their cars every 59 months
According to a frequently cited auto market research firm, the average time before the original owner transfers their vehicle -- purchased or leased -- is currently 59 months.Both studies mention that customers have a different "definition" of failure than manufacturers, and often replace the drives before they are completely kaput. The same is true for cars. Americans give various reasons why they trade in their less-than-five-year cars for newer models. Disk technologies advance at a faster pace, so it makes sense to change drives for other business reasons, for speed and capacity improvements, lower power consumption, and so on.
The CMU study indicated that 43 percent of drives were replaced before they were completely dead.So, if General Motors estimated their cars lasted 9 years, and Toyota estimated 11 years, people still replace them sooner, for other reasons.
At IBM, we remind people that "data outlives the media". True for disk, and true for tape. Neither is "permanent storage", but rather a temporary resting point until the data is transferred to the next media. For this reason, IBM is focused on solutions and disk systems that plan for this inevitable migration process. IBM System Storage SAN Volume Controller is able to move active data from one disk system to another; IBM Tivoli Storage Manager is able to move backup copies from one tape to another; and IBM System Storage DR550 is able to move archive copies from disk and tape to newer disk and tape.
If you had only one car, then having that one and only vehicle die could be quite disrupting. However, companies that have fleet cars, like Hertz Car Rentals, don't wait for their cars to completely stop running either, they replace them well before that happens. For a large company with a large fleet of cars, regularly scheduled replacement is just part of doing business.
This brings us to the subject of RAID. No question that RAID 5 provides better reliability than having just a bunch of disks (JBOD). Certainly, three copies of data across separate disks, a variation of RAID 1, will provide even more protection, but for a price.
Robin mentions the "Auto-correlation" effect. Disk failures bunch up, so one recent failure might mean another DDM, somewhere in the environment, will probably fail soon also. For it to make a difference, it would (a) have to be a DDM in the same RAID 5 rank, and (b) have to occur during the time the first drive is being rebuilt to a spare volume.
The human body replaces skin cells every day
So there are individual DDMs, manufactured by the suppliers above; disk systems, manufactured by IBM and others, and then your entire IT infrastructure. Beyond the disk system, you probably have redundant fabrics, clustered servers and multiple data paths, because eventually hardware fails.
People might realize that the human body replaces skin cells every day. Other cells are replaced frequently, within seven days, and others less frequently, taking a year or so to be replaced. I'm over 40 years old, but most of my cells are less than 9 years old. This is possible because information, data in the form of DNA, is moved from old cells to new cells, keeping the infrastructure (my body) alive.
Our clients should approach this in a more holistic view. You will replace disks in less than 3-5 years. While tape cartridges can retain their data for 20 years, most people change their tape drives every 7-9 years, and so tape data needs to be moved from old to new cartridges. Focus on your information, not individual DDMs.
What does this mean for DDM failures. When it happens, the disk system re-routes requests to a spare disk, rebuilding the data from RAID 5 parity, giving storage admins time to replace the failed unit. During the few hours this process takes place, you are either taking a backup, or crossing your fingers.Note: for RAID5 the time to rebuild is proportional to the number of disks in the rank, so smaller ranks can be rebuilt faster than larger ranks. To make matters worse, the slower RPM speeds and higher capacities of ATA disks means that the rebuild process could take longer than smaller capacity, higher speed FC/SCSI disk.
According to the Google study, a large portion of the DDM replacements had no SMART errors to warn that it was going to happen. To protect your infrastructure, you need to make sure you have current backups of all your data. IBM TotalStorage Productivity Center can help identify all the data that is "at risk", those files that have no backup, no copy, and no current backup since the file was most recently changed. A well-run shop keeps their "at risk" files below 3 percent.
So, where does that leave us?
ATA drives are probably as reliable as FC/SCSI disk. Customers should chose which to use based on performance and workload characteristics. FC/SCSI drives are more expensive because they are designed to run at faster speeds, required by some enterprises for some workloads. IBM offers both, and has tools to help estimate which products are the best match to your requirements.
RAID 5 is just one of the many choices of trade-offs between cost and protection of data. For some data, JBOD might be enough. For other data that is more mission critical, you might choose keeping two or three copies. Data protection is more than just using RAID, you need to also consider point-in-time copies, synchronous or asynchronous disk mirroring, continuous data protection (CDP), and backup to tape media. IBM can help show you how.
Disk systems, and IT environments in general, are higher-level concepts to transcend the failures of individual components. DDM components will fail. Cache memory will fail. CPUs will fail. Choose a disk systems vendor that combines technologies in unique and innovative ways that take these possibilities into account, designed for no single point of failure, and no single point of repair.
So, Robin, from IBM's perspective, our hands are clean. Thank you for bringing this to our attention and for giving me the opportunity to highlight IBM's superiority at the systems level.
It's Tuesday, and you know what that means? IBM Announcements! This week I am in beautiful Orlando, Florida for the [IBM Systems Technical University] conference.
This week, IBM announced its latest tape offerings for the seventh generation of Linear Tape Open (LTO-7), providing huge gains in performance and capacity.
For capacity, the new LTO-7 cartridges can hold up to 6TB native capacity, or 15TB effective capacity with 2.5x compression that for typical data. That is 2.4x larger than the 2.5TB catridges available with LTO-6. Performance is also nearly doubled, with a native throughput of 315 MB/sec, or effective 780 MB/sec effective capacity with 2.5x compression. The LTO consortium, of which IBM is a founding member, has published the roadmap for LTO generations to LTO-8, LTO-9 and LTO-10.
IBM will offer both half-height and full-height LTO-7 tape drives. All the features you love from LTO-6 like WORM, partitioning and Encryption carry forward. These drives will be supported on a variety of distributed operating systems, including Linux on z System mainframes, and the IBM i platform on POWER Systems.
The Linear Tape File System (LTFS) can be used to treat LTO-7 cartridges in much the same way as Compact Discs or USB memory sticks, allowing one person to create conent on an LTO-7 tape cartridge, and pass that cartridge to the next employee, or to another company. LTFS is also the basis for IBM Spectrum Archive that allows tape data to be part of a global namespace with IBM Spectrum Scale.
LTO-7 will be supported on the TS2900 auto-loader, as well as all of IBM's tape libraries: TS3100, TS3200, TS3310, TS3500 and TS4500. You can connect up to 15 TS3500 tape libraries together with shuttle connectors, for a maximum capacity of 2,700 drives serving 300,000 cartridges, for a maximum capacity of 1.8 Exabytes of data in a single system environment.
In addition to LTO-7 support, the IBM TS4500 tape library was also enchanced. You can now grow it up to 18 frames, and have up to 128 drives serving 23,170 cartridges, for a maximum capacity of 139 PB of data. You can now also intermix LTO and 3592 frames in the same TS4500 tape library.
For comptability, LTO-7 drives can read existing LTO-5 and LTO-6 tape cartridges, and can write to LTO-6 media, to help clients with transition.
Did you miss IBM Pulse 2013 this week? I wasn't there either, having scheduled visits with clients in Washington DC this week, only to have those meetings cancelled due to the [U.S. sequestration cuts].
Fortunately, there are plenty of videos and materials to review from the event. Here's a [12-minute video] interview between Laura DuBois, Program VP of Storage for industry analyst firm [IDC], and fellow IBM executive Steve "Woj" Wojtowecz, VP of Tivoli Storage and Networking Software.
(Update: Apparently, IBM had not secured re-distribution rights from IDC to post this video prior to my blog post. IBM now has full permission to distribute. My apologies for any inconvenience last week.)
The two discuss client opportunities and requirements for storage clouds and compute clouds. Client cloud storage requirements include backup and archive clouds, file storage clouds, and storage that supports compute cloud environments.
If you store your VMware bits on external SAN or NAS-based disk storage systems, this post is for you. The subject of the post, VM Volumes, is a potential storage management game changer!
Fellow blogger Stephen Foskett mentioned VM Volumes in his [Introducing VMware vSphere Storage Features] presentation at IBM Edge 2012 conference. His session on VMware's storage features included VMware APIs for Array Integration (VAAI), VMware Array Storage Awareness (VASA), vCenter plug-ins, and a new concept he called "vVol", now more formally known as VM Volumes. This post provides a follow-up to this, describing the VM Volumes concepts, architecture, and value proposition.
"VM Volumes" is a future architecture that VMware is developing in collaboration with IBM and other major storage system vendors. So far, very little information about VM Volumes has been released. At VMworld 2012 Barcelona, VMware highlights VM Volumes for the first time and IBM demonstrates VM Volumes with the IBM XIV Storage System (more about this demo below). VM Volumes is worth your attention -- when it becomes generally available, everyone using storage arrays will have to reconsider their storage management practices in a VMware environment -- no exaggeration!
But enough drama. What is this all about?
(Note: for the sake of clarity, this post refers to block storage only. However, the VM Volumes feature applies to NAS systems as well. Special thanks to Yossi Siles and the XIV development team for their help on this post!)
The VM Volumes concept is simple: VM disks are mapped directly to special volumes on a storage array system, as opposed to storing VMDK files on a vSphere datastore.
The following images illustrate the differences between the two storage management paradigms.
You may still be asking yourself: bottom line, how will I benefit from VM Volumes?
Well, take a VM snapshot for example. With VM Volumes, vSphere can simply offload the operation by invoking a hardware snapshot of the hardware volume. This has significant implications:
VM-Granularity: Only the right VMs are copied (with datastores, backing up or cloning individual-VM portions of hardware snapshot of a datastore would require more complex configuration, tools and work)
Hardware Offload: No ESXi server resources are consumed
XIV advantage: With XIV, snapshots consume no space upfront and are completed instantly.
Here's the first takeaway: With VM Volumes, advanced storage services (which cost a lot when you buy a storage array), will become available at an individual VM level. In a cloud world, this means that applications can be provisioned easily with advanced storage services, such as snapshots and mirroring.
Now, let's take a closer look at another relevant scenario where VM Volumes will make a lot of difference - provisioning an application with special mirroring requirements:
VM Volumes case: The application is ordered via the private cloud portal. The requestor checks a box requesting an asynchronous mirror. He changes the default RPO for his needs. When the request is submitted, the process wraps up automatically: Volumes are created on one of the storage arrays, configured with a mirror and RPO exactly as specified. A few minutes later, the requestor receives an automatic mail pointing to the application virtual machine.
Datastores case #1: As may be expected, a datastore that is mirrored with the special RPO does not exist. As a result, the automated workflow sets a pending status on the request, creates an urgent ticket to a VMware administrator and aborts. When the VMware admin handles that ticket, she re-assigns the ticket to the storage administrator, asking for a new volume which is mirrored with the special RPO, and mapped to the right ESXi cluster. The next day, the volume is created; the ticket is re-assigned to the storage admin, with the new LUN being pointed to. The VMware administrator follows and creates the datastore on top of it. Since the automated workflow was aborted, the admin re-assigns the ticket to the cloud administrator, who sometime later completes the application provisioning manually.
Datastores case #2: Luckily for the requestor, a datastore that is mirrored with the special RPO does exist. However, that particular datastore is consuming space from a high performance XIV Gen3 system with SSD caching, while the application does not require that level of performance, so the workflow requires a storage administrator approval. The approval is given to save time, but the storage administrator opens a ticket for himself to create a new volume on another array, as well as a follow-up ticket for the VMware admin to create a new datastore using the new volume and migrate the application to the other datastore. In this case, provisioning was relatively rapid, but required manual follow up, involving the two administrators.
Here's the second takeaway: With VM Volumes, management is simplified, and end-to-end automation is much more applicable. The reason is that there are no datastores. Datastores physically group VMs that may otherwise be totally unrelated, and require close coordination between storage and VMware administrators.
Now, the above mainly focuses on the VMware or cloud administrator perspective. How does VM Volumes impact storage management?
VM's are the new hosts: Today, storage administrators have visibility of physical hosts in their management environment. In a non-virtualized environment, this visibility is very helpful. The storage administrator knows exactly which applications in a data center are storage-provisioned or affected by storage management operations because the applications are running on well-known hosts. However, in virtualized environments the association of an application to a physical host is temporary. To keep at least the same level of visibility as in physical environments, VMs should become part of the storage management environment, like hosts. Hosts are still interesting, for example to manage physical storage mapping, but without VM visibility, storage administrators will know less about their operation than they are used to, or need to. VM Volumes enables such visibility, because volumes are provided to individual VMs. The XIV VM Volumes demonstration at VMworld Barcelona, although experimental, shows a view of VM volumes, in XIV's management GUI.
Here's a screenshot:
That's not all!
Storage Profiles and Storage Containers: A Storage Profile is a vSphere specification of a set of storage services. A storage profile can include properties like thin or thick provisioning, mirroring definition, snapshot policy, minimum IOPS, etc.
Storage administrators define a portfolio of supported storage services, maintained as a set of storage profiles, and published (via VASA integration) to vSphere.
VMware or cloud administrators define the required storage profiles for specific applications
VMware and storage administrators need to coordinate the typical storage requirements and the automatically-available storage services. When a request to provision an application is made, the associated storage profiles are matched against the published set of available storage profiles. The matching published profiles will be used to create volumes, which will be bound to the application VMs. All that will happen automatically.
Note that when a VM is created today, a datastore must be specified. With VM Volumes, a new management entity called Storage Container (also known as Capacity Pool) replaces the use of datastore as a management object. Each Storage Container exposes a subset of the available storage profiles, as appropriate. The storage container also has a capacity quota.
Here are some more takeaways:
New way to interface vSphere and storage management: Storage administrators structure and publish storage services to vSphere via storage profiles and storage containers.
Automated provisioning, out of the box: The provisioning process automatically matches application-required storage profiles against storage profiles available from the specified storage containers. There is no need to build custom scripts and custom processes to automate storage provisioning to applications
The XIV advantage:
XIV services are very simple to define and publish. The typical number of available storage profiles would be low. It would also be easy to define application storage profiles.
XIV provides consistent high performance, up to very high capacity utilization levels, without any maintenance. As a result, automated provisioning (which inherently implies less human attention) will not create an elevated risk of reduced performance.
Note: A storage vendor VASA provider is required to support VM Volumes, storage profiles, storage containers and automated provisioning. The IBM Storage VASA provider runs as a standalone service that needs to be deployed on a server.
To summarize the VM Volumes value proposition:
Streamline cloud operation by providing storage services at VM and application level, enabling end-to-end provisioning automation, and unifying VMware and storage administration around volumes and VMs.
Increase storage array ROI, improve vSphere scalability and response time, and reduce cloud provisioning lag, by offloading VM-level provisioning, failover, backup, storage migration, storage space recycling, monitoring, and more, to the storage array, using advanced storage operations such as mirroring and snapshots.
Simplify the adoption of VM Volumes using XIV, with smaller and simpler sets of storage profiles. Apply XIV's supreme fast cloning to individual VMs, and keep automation risks at bay with XIV's consistent high performance.
Until you can get your hands on a VM Volumes-capable environment, the VMware and IBM developer groups will be collaborating and working hard to realize this game-changing feature. The above information is definitely expected to trigger your questions or comments, and our development teams are eager to learn from them and respond. Enter your comments below, and I will try to answer them, and help shape the next post on this subject. There's much more to be told.
A reader from New Zealand expressed concern some corporate bloggers were [using the earthquake for marketing]. He lost someone close to him in Christchurch, and is unable to reach a friend living in Japan, so I am sorry for his loss. I plan to be in Australia and New Zealand to teach a Top Gun class May 15-27, so hopefully I will be able to meet him in person when I am down there.
"Earmarking funds is a really good way of hobbling relief organizations and ensuring that they have to leave large piles of money unspent in one place while facing urgent needs in other places. ... Meanwhile, the smaller and less visible emergencies where NGOs can do the most good are left unfunded.
In the specific case of Japan, there's all the more reason not to donate money. Japan is a wealthy country which is responding to the disaster, among other things, by printing hundreds of billions of dollars' worth of new money."
Another reader mentioned that the last surviving American WW-II vet died the same week. WTF? IBM and Japan have been allies for quite a while now, and there is no reason to bring up past wars except to compare the scope and magnitude of the cleanup effort. (Update: Frank Buckles was the last surviving WW-I vet, but also served in WW-II).
Many readers felt that charity begins at home, and there are plenty of worthy causes right here in the USA to donate to instead. Inspired by last year's movie [Waiting for Superman], my girlfriend started a project called [Centers for My Super Stars] for her first grade class on DonorsChoose.org. For those not familiar with this website, DonorsChoose.org uses the cloud to connect school teachers in need of supplies with rich people to donate funds towards these projects. If you want to contribute to her project, [donate here].
"And speaking of class, there just happens to be a baseball team in Sendai, Japan. The Golden Eagles. Their stadium was severely damaged from the earthquake. Wouldn't you think some of them lug nuts who run American baseball would bring the Golden Eagles and their opponents over to the United States when the Japanese season starts -- play some games over here and raise money to help the Japanese? Wouldn't you think they could just once stop that national pastime stuff and help the international pastime?"
As you can see, different readers have different opinions on this. We are all on this world together, and both our economy and our ecology are more interconnected than you might think. Let's build a smarter planet.
Full VMware Vstorage API for Array Integration (VAAI). Back in 2008, VMware announced new vStorage APIs for its vSphere ESX hypervisor: vStorage API for Site Recovery Manager, vStorage API for Data Potection, vStorage API for Multipathing. Last July, VMware added a new API called vStorage API for Array Integration [VAAI] which offers three primitives:
Hardware-assisted Blocks zeroing. Sometimes referred to as "Write Same", this SCSI command will zero out a large section of blocks, presumably as part of a VMDK file. This can then be used to reclaim space on the XIV on thin-provisioned LUNs.
Hardware-assisted Copy. Make an XIV snapshot of data without any I/O on the server hardware.
Hardware-assisted locking. On mainframes, this is call Parallel Access Volumes (PAV). Instead of locking an entire LUN using standard SCSI reserve commands, this primitive allows an ESX host to lock just an individual block so as not to interfere with other hosts accessing other blocks on that same LUN.
Quality of Service (QoS) Performance Classes.
When XIV was first released, it treated all hosts and all data the same, even when deployed for a variety of different applications. This worked for some clients, such as [Medicare y Mucho Más]. They migrated their databases, file servers and email system from EMC CLARiiON to an IBM XIV Storage System. In conjunction with VMware, the XIV provides a highly flexible and scalable virtualized architecture, which enhances the company's business agility.
However, other clients were skeptical, and felt they needed additional "nobs" to prioritize different workloads. The new 10.2.4 microcode allows you to define four different "performance classes". This is like the door of a nightclub. All the regular people are waiting in a long line, but when a celebrity in a limo arrives, the bouncer unclips the cord, and lets the celebrity in. For each class, you provide IOPS and/or MB/sec targets, and the XIV manages to those goals. Performance classes are assigned to each host based on their value to the business.
Offline Initialization for Asynchronous Mirror.
Internally, we called this Truck Mode. Normally, when a customer decides to start using Asynchronous Mirror, they already have a lot of data at the primary location, and so there is a lot of data to send over to the new XIV box at the secondary location. This new feature allows the data to be dumped to tape at the primary location. Those tapes are shipped to the secondary location and restored on the empty XIV. The two XIV boxes are then connected for Asynchronous Mirroring, and checksums of each 64KB block are compared to determine what has changed at the primary during this "tape delivery time". This greatly reduces the time it takes for the two boxes to get past the initial synchronization phase.
IP-based Replication. When IBM first launched the Storwize V7000 last October, people commented that the one feature they felt missing was IP-based replication. Sure, we offered FCP-based replication as most other Enterprise-class disk systems offer today, but many midrange systems also offer IP-based repliation to reduce the need for expensive FCIP routers. [IBM Tivoli Storage FastBack for Storwize V7000] provides IP-based replication for Storwize V7000 systems.
Network Attached Storage
IBM announced two new models of the IBM System Storage N series. The midrange N6240 supports up to 600 drives, replacing the N6040 system. The entry-level N6210 supports up to 240 drives, and replaces the N3600 system. Details for both are available on the latest [data sheet].
IBM Real-Time Compression appliances work with all N series models to provide additional storage efficiency. Last October, I provided the [Product Name Decoder Ring] for the STN6500 and STN6800 models. The STN6500 supports 1 GbE ports, and the STN6800 supports 10GbE ports (or a mix of 10GbE and 1GbE, if you prefer). The IBM versions of these models were announced last December, but some people were on vacation and might have missed it. For more details of this, read the [Resources page], the [landing page], or [watch this video].
IBM System Storage DS3000 series
IBM System Storage [DS3524 Express DC and EXP3524 Express DC] models are powered with direct current (DC) rather than alternating current (AC). The DS3524 packs dual controllers and two dozen small-form factor (2.5 inch) drives in a compact 2U-high rack-optimized module. The EXP3524 provides addition disk capacity that can be attached to the DS3524 for expansion.
Large data centers, especially those in the Telecommunications Industry, receive AC from their power company, then store it in a large battery called an Uninterruptible Power Supply (UPS). For DC-powered equipment, they can run directly off this battery source, but for AC-powered equipment, the DC has to be converted back to AC, and some energy is lost in the conversion. Thus, having DC-powered equipment is more energy efficient, or "green", for the IT data center.
Whether you get the DC-powered or AC-powered models, both are NEBS-compliant and ETSI-compliant.
New Tape Drive Options for Autoloaders and Libraries
IBM System Storage [TS2900 Autoloader] is a compact 1U-high tape system that supports one LTO drive and up to 9 tape cartridges. The TS2900 can support either an LTO-3, LTO-4 or LTO-5 half-height drive.
IBM System Storage [TS3100 and TS3200 Tape Libraries] were also enhanced. The TS3100 can accomodate one full-height LTO drive, or two half-height drives, and hold up to 24 cartridges. The TS3200 offers twice as many drives and space for cartridges.
If we have learned anything from last decade's Y2K crisis, is that we should not wait for the last minute to take action. Now is the time to start thinking about weaning ourselves off Windows XP. IBM has 400,000 employees, so this is not a trivial matter.
Already, IBM has taken some bold steps:
Last July, IBM announced that it was switching from Internet Explorer (IE6) to [Mozilla Firefox as its standard browser]. IBM has been contributing to this open source project for years, including support for open standards, and to make it [more accessible to handicapped employees with visual and motor impairments]. I use Firefox already on Windows, Mac and Linux, so there was no learning curve for me. Before this announcement, if some web-based application did not work on Firefox, our Helpdesk told us to switch back to Internet Explorer. Those days are over. Now, if a web-based application doesn't work on Firefox, we either stop using it, or it gets fixed.
IBM also announced the latest [IBM Lotus Symphony 3] software, which replaces Microsoft Office for Powerpoint, Excel and Word applications. Symphony also works across Mac, Windows and Linux. It is based on the OpenOffice open source project, and handles open-standard document formats (ODF). Support for Microsoft Office 2003 will also run out in the year 2014, so moving off proprietary formats to open standards makes sense.
I am not going to wait for IBM to decide how to proceed next, so I am starting my own migrations. In my case, I need to do it twice, on my IBM-provided laptop as well as my personal PC at home.
Last summer, IBM sent me a new laptop, we get a new one every 3-4 years. It was pre-installed with Windows XP, but powerful enough to run a 64-bit operating system in the future. Here are my series of blog posts on that:
I decided to try out Red Hat Enterprise Linux 6.1 with its KVM-based Red Hat Enterprise Virtualization to run Windows XP as a guest OS. I will try to run as much as I can on native Linux, but will have Windows XP guest as a next option, and if that still doesn't work, reboot the system in native Windows XP mode.
So far, I am pleased that I can do nearly everything my job requires natively in Red Hat Linux, including accessing my Lotus Notes for email and databases, edit and present documents with Lotus Symphony, and so on. I have made RHEL 6.1 my default when I boot up. Setting up Windows XP under KVM was relatively simple, involving an 8-line shell script and 54-line XML file. Here is what I have encountered:
We use a wonderful tool called "iSpring Pro" which merges Powerpoint slides with voice recordings for each page into a Shockwave Flash video. I have not yet found a Linux equivalent for this yet.
To avoid having to duplicate files between systems, I use instead symbolic links. For example, my Lotus Notes local email repository sits on D: drive, but I can access it directly with a link from /home/tpearson/notes/data.
While my native Ubuntu and RHEL Linux can access my C:, D: and E: drives in native NTFS file system format, the irony is that my Windows XP guest OS under KVM cannot. This means moving something from NTFS over to Ext4, just so that I can access it from the Windows XP guest application.
For whatever reason, "Password Safe" did not run on the Windows XP guest. I launch it, but it takes forever to load and never brings up the GUI. Fortunately, there is a Linux version [MyPasswordSafe] that seems to work just fine to keep track of all my passwords.
Personal home PC
My Windows XP system at home gave up the ghost last month, so I bought a new system with Windows 7 Professional, quad-core Intel processor and 6GB of memory. There are [various editions of Windows 7], but I chose Windows 7 Professional to support running Windows XP as a guest image.
Here's is how I have configured my personal computer:
I actually found it more time-consuming to implement the "Virtual PC" feature of Windows 7 to get Windows XP mode working than KVM on Red Hat Linux. I am amazed how many of my Windows XP programs DO NOT RUN AT ALL natively on Windows 7. I now have native 64-bit versions of Lotus Notes and Symphony 3, which will do well enough for me for now.
I went ahead and put Red Hat Linux on my home system as well, but since I have Windows XP running as a guest under Windows 7, no need to duplicate KVM setup there. At least if I have problems with Windows 7, I can reboot in RHEL6 Linux at home and use that for Linux-native applications.
Hopefully, this will position me well in case IBM decides to either go with Windows 7 or Linux as the replacement OS for Windows XP.