Evaluation of three I/O schedulers
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]
Quoted 4 lines · Peter Wong
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?
Signature · 2 lines
Dave Hansen [email protected]
Quoted 7 lines · 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.
Quoted 5 lines
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