Evaluation of three I/O schedulers

[Peter Wong]

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: [e-mail]