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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)."
How about a slashdot policy of not linking to articles behind paywalls?
Seriously, it's even worse than the "free registration required" links that we used to have problems with.
Original PDF at http://research.microsoft.com/pubs/76522/tr-2008-169.pdf.
Page 1 Microsoft Research Ltd. Technical Report MSR-TR-2008-169, November 2008 Not a thing to do with it.
No statement is true, not even this one.
These days, hard drives are cheaper than tapes and will hold their data longer and more compatibly.
That's entirely false.
Hard drives are vastly cheaper than tape drives, but enterprise quality tape is stil cheaper than enterprise quality HDDs.
Enterprise tape has a proven 20-year shelf life, no HDD does.
I wrote new commercial software that could (and did) work with IBM's 9-track tape format in 1994, 30 years after it released, and there is still hardware and software in use today that can read that hardware format - 45 years of compatibility. The abstract format - ANSI tape labels - is still in niche use for newly saved data today. DLT format is 25 years old, and while I'm not sure you can buy a new drive that reads the original DLT format, used drives are still easy to come by and you can connect them to new SCSI cards.
How easy is it to read an MFM drive (assuming there are more than 0 in the world that still work)? That format is 30 years old, and it would be a real challenge to find a slot on a modern PC that would take an MFM controller, vastly harder than reading a DLT tape. FAT is also about 30 years old, but disk formats older than that are basically extinct.
Socialism: a lie told by totalitarians and believed by fools.
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.
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.
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? ]=-
They're not the only ones pulling numbers out of their ass. You also seem to be too, unless you're finding the absolutely most expensive drive in any given capacity class.
For example, the 80GB Intel X25-M runs around $380, so is better than any of the prices you pulled up.
Obviously, it doesn't make sense to replace every drive in a server farm with SSDs, especially if you want lots of storage, but you have to keep in mind that while SSDs may suck for GB/$, they do have major advantages in other areas, such as MB/S/$ - That Intel X25-M is FAST, and if you are primarily interested in serving lots of small transactions rather than storing big files, it's the way to go.
For example, Slashdot is probably better off with an array of X25-Ms because it's only storing text and is getting LOTS of hits.
retrorocket.o not found, launch anyway?
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.)