Saturday, June 02, 2007

INNODB Disk setup and mount options

Assumptions:

RHEL
x86_64
EXT3
RAID

What Raid to use?
RAID-10

Why?
It's faster. RAID-5 offers more disk space but the parity bit messes things up, unless you have some uber hardware-raid card that caches that operation. Personally I am not a fan.


Stripe Size:
128K - this is really good for INNODB, you'll see a huge boost in responsiveness by making your Stripe Size 128K. I had a 64K stripe size, and I was blown away by the improvement of 128K


Mount options:

mkfs.ext3 -T largefile | mkfs.ext3 -T largefile4

Unless your going to have millions of files, this is a good option.


Make sure /etc/fstab mounts the mysql partition or the data that mysql resides on with noatime.

atime is accesstime: this is a huge boost in performance, tracking each time your ibdata file was last access is worthless, so don't do it.



From other benchmarks that I ran, I think that IBM's open source File system may be better then ext3 for certain workloads. Once I have more information I will post it here.

3 comments:

  1. Thanks for the 128k hint.. I'll have to try that ...

    Also... ext3 and not XFS?

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  2. I'd go XFS over ext3 for performance.

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  3. Using RHEL-4 doesn't support XFS, RHEL-5 - so for now I need to stick with ext3.

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