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purplemonkeydishwasher
Asked: 2011-01-27 19:33:27 +0800 CST

RAID of SATA SSDs or PCIe Flash?

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As a reference:

  • Crucial RealSSD C300 256GB drives.
  • MySQL 5.1.5x running InnoDB tables.
  • Linux (CentOS 5.5 etx3 journaled).

Questions:

  1. Is it better to use a RAID of these so that drives can be swapped in and out or get a FusionIO or RevoDrive card?

  2. If RAID, what controller? LSI? 3Ware?

  3. What layout? I would presume the RAID 5 hole doesn't apply as much to SSD since the rebuild time is much less. Bad assumption?

  4. If a flash card, what card?

  5. Better to move to Solaris and ZFS and skip the cards and pick up other goodies along with? I have only experience with Linux so the move to Solaris would be uncomfortable though doable.

mysql solaris raid ssd flash-drive

1 Answers

    1. I see you're thinking about using ZFS, if you do be aware that it changes most of your design considerations. ZFS is not just another file system, it's also a volume manager rolled in. If your going this direction please update the question and I'll be more specific.

      Multiple SSDs will quickly saturate most RAID cards, though top end cards can easily handle them. PCIe storage cards are generally faster, cost more, and many MBs will not boot from them yet.

    2. Need more info on your requirements...

    3. RAID5 hole always applies (though it's effects can be largely mitigated, depends on your setup and what you're using it for)

    4. FusionIO are very expensive. RevoDrive are more for enthusiasts, they don't have much reserve either. If your application is write intensive, it may kill the RevoDrive within your expected lifetime.

    5. See above for my comment about ZFS. Honestly, if you're thinking about it (and willing to take the plunge) I'd suggest it. The L2ARC, ZIL, Dedupe, snapshot, ACL, etc, etc, features put it far ahead of the competition and takes the rest of this discussion in a different direction. Also, the BSDs support ZFS and are improving their support for it extensively right now. Linux also supports it, though they're a bit behind because of license incompatibilities.

    Standard Disclaimer - I have very little knowledge of your specific requirements and environment; take all this with a huge grain of salt.

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