SQL Server and RAID 5

The RAID 5 IOMeter results were interesting and peculiar enough to warrant another testing round with SQLIO. First, we start with the least useful but "pedal to the metal" benchmark: sequential reads and writes.

RAID 5 SQLIO Sequential Read (64KB)

RAID 5 SQLIO Sequential Write (64KB)

Although hardly surprising, both results are another confirmation that the SLC drives are limited by the SATA interface and the RAID controller combination.

RAID 5 SQLIO Random Read (8KB)

Random reads perform as expected. The SLC SSD drives completely annihilate the magnetic disk competition.

RAID 5 SQLIO Random Write (8KB)

Random writes in RAID 5 are not only a complete disaster, they also confirm our theory that adding more X25-E SLC drives does not help as the storage processor cannot deliver the necessary RAID-5 processing that the SLC drives demand. The more drives you add, the worse the random writing performance becomes.

More RAID 5 Testing in the Real World
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  • shady28 - Sunday, November 15, 2009 - link


    I would have really like to see single drive performance of SAS 15K drives vs SSDs. The cost of a SAS controller ($60) + a 15K 150Gig drive ($110-$160) is less than any of the high end SSDs, and about the same as a low end SSD. It's a viable option to get a 15K Drive, but very difficult to see what is the best choice when looking at RAID configs and database IOPs.
    Reply
  • newriter27 - Tuesday, May 05, 2009 - link

    What was the Queue Depth setting used with IOmeter? Was it maintained consistently?

    Also, how come no response times?

    Reply
  • mikeblas - Friday, April 17, 2009 - link

    Intel has posted a firmware upgrade for their SSD drives which tries to address the write leveling problem. The patch improves matters, somewhat, but the overall performance level from the drives is still completely unacceptable for production applications.

    You can find it here: http://www.intel.com/support/ssdc/index_update.htm">http://www.intel.com/support/ssdc/index_update.htm
    Reply
  • Lifted - Sunday, April 12, 2009 - link

    I like it! Reply
  • turrican2097 - Monday, March 30, 2009 - link

    Please mention or correct this on your article.
    1) You should mention that the price per GB is 65x higher than the 1TB drives, since you chose to include them.
    2) Your WD is a poor performance 5400RPM Green Power drive: http://www.techreport.com/articles.x/16393/8">http://www.techreport.com/articles.x/16393/8
    3) If you make such a strong point on how much faster SSDs are than platters, you can't pick the best SSD and then use the hardrives you happen to have laying around the lab. Pick Velociraptors or WD RE3 7200RPM and then Seagate 15K7.

    Thank you
    Reply
  • mutantmagnet - Monday, April 06, 2009 - link

    It's irrelevant. Raptors don't outperform SAS which are better in terms of performance for the GB paid for. There's no need to belittle them when they are clearly aware of the type of point you are making and went beyond it.

    So far I've found these recent SSD articles to be a fun and worthwhile read; and the comments have been invaluable, even if some people sound a little too aggressive in making their points.
    Reply
  • virtualgeek - Friday, March 27, 2009 - link

    Just wanted to point this out - we are now shipping these 200GB and 400GB SLC-based STEC drives in EMC Symmetrix, CLARiiON and Celerra. These are the 2nd full generation of EFDs.

    Gang - this IS the future of performance-oriented storage (not implying it will be EMC-unique - it won't be - everyone will do it - from the high end to the low end) - only a matter of time (we're currently at the point where they are 1/3 the acquisition cost to hit a given IOPS workload - and they have dropped by a factor of 4x in ONE YEAR).

    With Intel and Samsung entering to the market full force - the price/performance/capacity curve will continue to accelerate.
    Reply
  • ms0815 - Friday, March 27, 2009 - link

    Since modern Graphic cards crack passwords more than 10 times faster than a CPU, wouldn't they also be greate Raid Controllers with their massive paralel design? Reply
  • Casper42 - Thursday, March 26, 2009 - link

    I would have liked to have seen 2 additional drives tossed into the mix on this one.

    1) The Intel X25-M - Because I think it would serve as a good middleground between the SAS Drives and the E model. Cheaper/GB but still gets you a much faster Random Read result and I'm sure a slightly faster Random Write as well.

    2) 2.5" SAS Drives - Because mainstream servers like HP and Dell seem to be going more and more this direction. I don't know many Fortune 500s using Supermicro. 2.5" SAS goes up to 72GB for 15K and 300GB for 10K currently. Though I am hearing that 144GB 15K models are right around the corner.

    Thanks for an interesting article!
    Reply
  • MrSAballmer - Thursday, March 26, 2009 - link

    SDS with ATA!

    http://www.youtube.com/watch?v=x4dxTRkODbE">http://www.youtube.com/watch?v=x4dxTRkODbE

    http://fakesteveballmer.blogspot.com">http://fakesteveballmer.blogspot.com
    Reply

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