We used 2.5.72+mm1 to evaluate three I/O schedulers, namely
anticipatory, deadline and complete fair queueing under a very heavy
database workload on an 8-way Pentium 4 machine. The workload is a
decision support system doing mostly sequential I/O and each run takes
about one hour. All three runs finished completely without encountering
functional problems, and achieved similar performance level.
The 8-way machine has Pentium 4 2.0 GHz processors, 16 GB physical
memory, 2MB L3 cache, 8 FC controllers with 80 disks. Hyperthreading
was turned on for the three runs. The CPU utilization is similar for all
three runs: 65% user, 7% system and 28% idle.
Regards,
Peter
Peter Wai Yee Wong
IBM Linux Technology Center Performance Team
email: [email protected]
On Mon, 2003-06-30 at 07:21, Peter Wong wrote:
> The 8-way machine has Pentium 4 2.0 GHz processors, 16 GB physical
> memory, 2MB L3 cache, 8 FC controllers with 80 disks. Hyperthreading
> was turned on for the three runs. The CPU utilization is similar for all
> three runs: 65% user, 7% system and 28% idle.
Could you give us an idea of how greatly utilized your 10 fiber
controllers are? What about memory? Would a larger readahead be
beneficial?
--
Dave Hansen
[email protected]
Peter Wong wrote:
>We used 2.5.72+mm1 to evaluate three I/O schedulers, namely
>anticipatory, deadline and complete fair queueing under a very heavy
>database workload on an 8-way Pentium 4 machine. The workload is a
>decision support system doing mostly sequential I/O and each run takes
>about one hour. All three runs finished completely without encountering
>functional problems, and achieved similar performance level.
>
>The 8-way machine has Pentium 4 2.0 GHz processors, 16 GB physical
>memory, 2MB L3 cache, 8 FC controllers with 80 disks. Hyperthreading
>was turned on for the three runs. The CPU utilization is similar for all
>three runs: 65% user, 7% system and 28% idle.
>
Hi Peter,
How many block devices are being used at once in your tests?
I would be interested to see profiles of AS and DL if possible.
Thanks.
Nick