Ross S. W. Walker 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.
But if it weren't for the accumulation of stuff in the raid card queue,
other processes should get an equal shot fairly quickly. I think that
raid card just treats draining the whole queue as one operation.
>>> 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.
What does that mean if it needs more than the available space to
complete a single operation - like a multi-table join that decides to
copy the whole tables to temp files?
--
Les Mikesell
lesmikesell at gmail.com