Re: Advice configuring ServeRAID 8k for performance

Scott Carey wrote:
> Don't ever have WAL and data on the same OS volume as ext3.
>
> If data=writeback, performance will be fine, data integrity will be ok
> for WAL, but data integrity will not be sufficient for the data
> partition.  If data=ordered, performance will be very bad, but data
> integrity will be OK.
>
> This is because an fsync on ext3 flushes _all dirty pages in the file
> system_ to disk, not just those for the file being fsync'd.
>
> One partition for WAL, one for data.  If using ext3 this is essentially
> a performance requirement no matter how your array is set up underneath.

Do we need to document this?

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + It's impossible for everything to be true. +