[Gllug] Poor disk performance on IDE raid

[Daniel P. Berrange]

On Fri, Jun 03, 2005 at 10:43:51AM +0100, Simon Wilcox wrote:
> >    Which filing system? ext2? ext3? Reiser? Is it very different on write?
> 
> Sorry, ext3. I've not benchmarked writing, I was just curious about the
> amount if time spent in IO wait.

With journalling remember that even file reads can actually generate disk
writes because they cause the access time to be updated on the file, 
which in turns requires journal to be updated. So for files or partitions
for which access time is not important (ie log files, database data
files, mail boxes) you can get some benefit from using the 'noatime'
flag on the file or partition to disable updating of access time.

Dan.
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