Re: Miserable Disks

Comments inline.

On 5/25/06, Mark Brinsmead <pythianbrinsmead_at_gmail.com> wrote:
>
>
> (*) Make your RAID stripe width really narrow (like maybe 128 or 512
> bytes) and then
> make your database blocks large (like 8KB or 16KB) and do lots of
> multi-block I/O,
> so that every I/O is assured to engage every physical drive. (Kiss
> concurrency goodbye
> and watch your RIOPs numbers plummet)
>

Seems like somthing like this might be optimal for single session. Benchmarks? ;)

(*) Get the biggest cache you can afford. (Make sure it's *really*
> non-volatile. Wolfgang
> never mentioned what happens to your database when you lose the contents
> of the write
> cache, but *I* got a taste! And it wasn't pleasant!)
>

Yes, I had experience with that 2 weeks ago on a CX700. Definitely unpleasant.

EMC claimed that we should have disable the write cache prior to powering down the SAN.

I have since learned that the support tech in question was blowing smoke.

-- 
Jared Still
Certifiable Oracle DBA and Part Time Perl Evangelist

--
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