Les Mikesell wrote:
>
> Ross S. W. Walker wrote:
> >
> > Yes, IO starvation can occur under heavy load.
>
> But it should stall the process needing to write, not everything.
There is only 1 disk though and if that disk is busy writing it
can't read.
It would be nice if disk manufacturers made full duplex disks
with 1 set of heads for writing and another set of heads for
reading, but they don't :-(
> > Don't put database temp tables on system disks (or data
> tables for that matter).
> >
> > How much memory do you have in this box and how big does
> the temp directory
> > usage get?
> >
> > Why I ask is you could create a tempfs and have mysql use
> that, just make sure
> > you have enough memory that you can spare X (whatever your
> temp table usage is)
> > for a cache filesystem.
> >
> > You would also notice a dramatic speed increase in MySQL.
>
> I'm not sure the needed temp table space is predictable. I've seen
> mysql be pretty dumb about how it does a select that joins
> several tables.
True, but take an average and that should suffice, MySQL will wait
if temp space fills up.
-Ross
______________________________________________________________________
This e-mail, and any attachments thereto, is intended only for use by
the addressee(s) named herein and may contain legally privileged
and/or confidential information. If you are not the intended recipient
of this e-mail, you are hereby notified that any dissemination,
distribution or copying of this e-mail, and any attachments thereto,
is strictly prohibited. If you have received this e-mail in error,
please immediately notify the sender and permanently delete the
original and any copy or printout thereof.
_______________________________________________
CentOS mailing list
CentOS@xxxxxxxxxx
http://lists.centos.org/mailman/listinfo/centos
