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MS Researchers Call Moving Server Storage To SSDs a Bad Idea
An anonymous reader writes "As an IT administrator did you ever think of replacing disks by SSDs? Or using SSDs as an intermediate caching layer? A recent paper by Microsoft researchers provides detailed cost/benefit analysis for several real workloads. The conclusion is that, for a range of typical enterprise workloads, using SSDs makes no sense in the short to medium future. Their price needs to decrease by 3-3000 times for them to make sense. Note that this paper has nothing to do with laptop workloads, for which SSDs probably make more sense (due to SSDs' ruggedness)."
News at 11!
This is an ACM article behind a paywall.
How about a slashdot policy of not linking to articles behind paywalls?
Test your net with Netalyzr
Hm. I was thinking the same thing about the ACM subscription.
I'm a 2000 man.
SSD is already cheaper per gig than some SAS drives. Also, 3-3000 times? What the hell sort of estimate is that?
they don't use NTFS?
One of our competitors trademarked the term "hypothesis". From now on, we will call them "boneheaded ideas".
It's called "pulling numbers out of your ass".
My goodness! They have really done their research in order to produce data as accurate as that!
The fact was, they said the same thing when it came to magnetic tape versus magnetic disks. These days, hard drives are cheaper than tapes and will hold their data longer and more compatibly.
Microsoft fears change that they do not control. If they don't control the changes, someone might write them out of the story.
What do you mean, an african or european ass?
seriously? "we don't have enough people here. we need between 2-2000 times as many people in the configuration department." Does that sound like I have ANY idea how many people we need?
Sorry, that is a *ridiculous* range to give.
Of course, SAS drives are also often too expensive to survive a purely cost/benefit driven analysis. For many real-world loads you're better off adding more spindles which can give you similar iops per dollar but with the added benefit of vastly more storage space.
There's a lot of snake oil and very little quality analysis in enterprise storage these days, so it's good to see at least some do attempt to do actual real-world cost/benefit calculations before jumping onto the marketing train.
That wasn't hard.
Page 1 Microsoft Research Ltd. Technical Report MSR-TR-2008-169, November 2008 Not a thing to do with it.
What a misleading term - I know of companies using Enterprise SSD in production precisely because it's financially sound for them to utilise the ridiculous speed improvement it provides.
Sure, it's not a lot of companies that are using this yet, but as longevity increases with better garbage collection and write-spreading algorithms as well as stabilty and feature set through maturing software and firmware it's closer than you think.
For clarity, the product wasn't SSD behind SATAII, it was FusionIO's PCI devices.
No statement is true, not even this one.
Since when are we supposed to read the articles?
Microsoft researchers provides detailed cost/benefit analysis for several real workloads.
If Microsoft researchers report that SSD's are not cost effective storage, it means that Microsoft is not getting any revenue from SSD storage. Or that they're behind on incorporating SSD's into the server stack. Or they caught blind-sided by the trend like they did with netbooks and are now scrambling to explain why they didn't see it coming. Oh, we found that wasn't cost effective, so we didn't incorporate it.
I really miss the days Microsoft had it together. There was a time they were great to work with. Now they seem like the Three Stooges Do IT. SSD, eh? Oh, a wise guy! SMACK! Wo-wo-wo-wo!
That's our life, the big wheel of shit. - The Fat Man, Blue Tango Salvage
Windows 2020 will have the same features as Open Solaris 10, just wait and see. They will be able to use a SSD as a cache reader I swear!
They could call it... ReadyBoost.
They list the write IOPS of their "Enterprise SSD" drive as only ~350. That number seems like it's an order of magnitude too low, which would obviously skew the conclusions.
http://blogs.sun.com/brendan/entry/test has some background information, and http://blogs.sun.com/brendan/entry/l2arc_screenshots and http://blogs.sun.com/brendan/entry/my_sun_storage_7410_perf has some performance numbers.
Basically, what Sun is claiming is that by adding a SSD cache layer you can improve IOPS by about 5x, for what amounts to a really small amount of money for say a 100tb system. This is being marketed quite heavily by Sun as well. (The numbers look convincing, and the prices for the Sun Storage servers are certainly very competitive, well, compared to say NetApp.)
IMHO this is just a repeat of the well known Microsoft tactic of spreading massive amounts of FUD about any competing technology that you can't reproduce yourself - you'll have to wait until Windows Server 2013 for this.
Dismissing using SSD because it's only cost effective for the boot partition is a mistake. Anyone who's put together servers before knows the boot partition is critical to the system, and the hardest part to backup. Once you get a system booted, there's a million things you can do to fix it or restore the relevant data. Getting it bootable if the boot partition is toast is much harder.
AccountKiller
Since this paper is focused on solid-state storage, and wear is a novel, SSD-specific phenomenon, we include it in our device models. Currently we do not model other failures, such as mechanical failures in disks.
The correct approach to incomplete data is, of course, to gather complete data, and they have no excuse here, because there is PLENTY of data on mechanical drive failure rates. However, if you are not willing to do that, the least you can do is ignore the data equally on both sides. The authors' failure to treat both sides equally leads to a hopelessly biased and skewed analysis.
I just finished the reading the paper.
The paper boils down to this:
SSD disk when measured against IOPS, Watts, and Capacity in relation to cost based on several different server types is not cost effective yet. Depending on the type of server costs need to come down at least 3 fold, and under some scenarios as much as 3000 times. Hosting MP3s that are largely sequental, low write storage SSDs are 3000 times over priced. For insaine random IO scenarios that need to come down 3 fold to make it worth it compared to conventional drives.
Depending on the type of server they can perform worse then standard mechanical disks.
They found no advantage to 15k RPM drives versus 10k RPM drives when cost is factored in.
SSD drives pay for themselves in power saving in about 5 years, well past their expected longevity.
Mechanical disks wear out more or less independant of their data load, SSDs wear out proportional to their data load.
SSDs do not handle tiny files very well due to how data is written.
I see nothing in the paper that is pro-microsoft, rather straight dealing on the drives themselves.
I would suggest MOD-TROLL any evanglest on any side of the OS wars as this paper doesn't seem to deal with OS touting.
It was a boring but informative read.
-=[ Who Is John Galt? ]=-
For read data, it makes more economic sense to cache to RAM instead of SSD and just read everything into RAM at startup. Fpr writes, I'm not that sure -- is a write to SSD really that much faster than a write to disk? It might make sense to use SSD for journaling in those cases where a transaction can't complete until you are certain the results have been saved. But in that case, your network latencies are probably much greater than you disk write latency anyway.
I've abandoned my search for truth; now I'm just looking for some useful delusions.
They could grip it by the husk!
A slashdotter who didn't build his own computer is like a Jedi who didn't build his own lightsaber.
No 350 IOPS is pretty standard for SSD in real world conditions.
Intel specs their X25-E at 3300 IOPS for random 4K writes. I'm willing to consider there might be a bit of fudge factor in that number (although all the benchmarks I've seen suggest it is conservative, if anything), but certainly not an order of magnitude.
A well designed RAID in a robust SAN can survive not just the death of a drive but often the death of an entire enclosure (10-16 drives depending on age and enclosure design). Most of the time a small enterprise class SAN has 8-12 enclosures worth of drives. Big ones can span half a dozen or more racks. I don't think this article is talking about a couple drives thrown into a box with a hardware RAID controller here. When a player like Microsoft starts talking about "storage" they are talking 100 TB or more. Last place I worked had ONLY 25 TB of storage, made up of older storage tech that only gave us 300 GB FC drives. We had 8x14 disk enclosures and could loose and entire enclosure without data loss. The disks were striped in such a way as to ensure that none of our RIAD5s had more than one disk in any one enclosure, and 4 spares made sure that up to 4 disks could die before we even had a chance of any long term performance issues. If you're really paranoid you can build a RAID5+1 to make sure that up to two drives per RAID could die without data loss. I've heard of, but not seen companies so paranoid that they use RAID5+2.
The storage system at my current place is even fancier and dynamically handles the RAIDs. We've got about 100TB spread across two racks worth of enclosures and any 20 or so disks could die at one time before we lost data.
I don't need a million points of light, just two points of multi-mode fiber and a 10 Gig-E router.
One thing about this research paper is that they used only one model MemoRight GT MR25.2 in 8/16/32 GB capacities to do their testing before 2008-11-11 publication of the paper in the United Kingdom.
I'm concerned that the research test and results are largely skewed against SSDs because they used only that one model to do all their testing with based on only one price point for the SSDs.
There is a very large difference in performance between many various SSD drives based on the original flawed JMicron JMF602 chipset (stuttering/freezing on write), newer JMF602B (smaller stuttering), Samsung's chipset, Intel's chipset (fastest random writes by 4x), and the newest Indilnix Barefoot chipset (balanced sequential/random read/write). Additionally the huge drops in prices in the last 6-12 months ($1,500->$400) is a big change in the SSD arena. These price, capacity, and performance changes are going to continue fluctuating for the next few years yielding much better drives for the consumers.
I believe that the research in the paper will be shortly obsolete, if it isn't already, given the latest products on the market and price points and the Q3/Q4 new upcoming products from Intel and others.
I'm helping a friend of mine build an all-in-one HTPC / Desktop / Gaming system and I've been doing research into SSDs for the past few weeks based on reviews and benchmarks so I wanted to share my info.
Basically there are only two drives to consider and I list them below. A good alternative at this time is to purchase smaller SSDs and create RAID-0 (stripping) sets to effectively double their performance instead of buying a single large SSD. The RAID-0 article below shows great benchmark results to this effect.
Intel X25-M
The Intel X25-M series of drives is the top performance leader right now, and the 80GB drive is barely affordable for a desktop system build if you consider the increased performance of the drive.
Intel X25-M SSDSA2MH080G1 80GB SATA Internal Solid state disk (SSD) - Retail - $383.00 USD ($ 4.7875 / per GB)
OCZ Vertex
The new OCZ Vertex series of drives with the newer 1275 firmware is the price/performance leader and they are much more affordable than the Intel drives. When you combine two of these smaller 30/60 GB drives into RAID-0 (stripping) you get double the performance at still acceptable prices.
OCZ Vertex Series OCZSSD2-1VTX30G 2.5" 30GB SATA II MLC Internal Solid state disk (SSD) - Retail - $129.00 USD ($ 4.3 / per GB)
OCZ Vertex Series OCZSSD2-1VTX60G 2.5" 60GB SATA II MLC Internal Solid state disk (SSD) - Retail - $209.00 USD ( $ 3.483 / per GB)
Reviews
Required Reading:
AnandTech - The SSD Anthology: Understanding SSDs and New Drives from OCZ
AnandTech - Intel X25-M SSD: Intel Delivers One of the World's Fastest Drives
AnandTech - The SSD Update: Vertex Gets Faster, New Indilinx Drives and Intel/MacBook Problems Resolved
RAID-0 Performance:
ExtremeTech - Intel X25 80GB Solid-State Drive Review - PCMark Vantage Disk Tests
BenchmarkReviews - OCZ Vertex SSD RAID-0 Performance
(Be Warned about BenchmarkReviews! Synthetic benchmark results only, no real-life benchmarks such as PCMark Vantage.)
"As an IT administrator did you ever think of replacing disks by SSDs? Or using SSDs as an intermediate caching layer?
SSDs aren't big enough for some uses as mass storage but they could speed up things if used as a cache.
Note that this paper has nothing to do with laptop workloads, for which SSDs probably make more sense (due to SSDs' ruggedness)."
I think laptops are where SSDs can come into their own. There shouldn't as much need to large mass storage and SSDs extend battery life. Having said that, I replaced the 160GB HDD in my 1 1/2 year old laptop with a 320GB drive, the biggest I could find.
Falcon
Should there be a Law?
Today you just buy 2.5" drives with 2" platters, much more cost effective =) As an example HP 146GB 15K 2.5" has a full stoke latency of 4.85ms, nearly as fast as the average (short stroke) latency of a 144GB 10K 3.5" drive (3.9ms). No way the 2.5" cost 2x more =)
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
The only real difference between the two in the SSD world is the 'enterprise' and 'extreme' tend to be SLC rather than MLC. It'll be a matter of time before the performance difference between the two will be so minor that it'll be difficult to justify the higher price tag for performance alone.