We are testing out different RAID configurations for our new Splunk indexers using bonnie++ and have found some unexpected results.
Even though this article claims that RAID 5 "will offer the worst performance" we found the highest random seek / sec with RAID 5 which I believe is the IOPS number that is always being quoted by Splunk users.
We tested RAID 5, 10 and 50 using 6 disks. We ran bonnie with sizes of 2x and 4x the RAM (16G) using:
bonnie++ -d /opt/bonnie_test -s 32g -qfb
bonnie++ -d /opt/bonnie_test -s 64g -qfb
Here are the average of 4 runs each:
Full sized image here.
I expected all round superior numbers with RAID 10 prior to seeing the results.
Any ideas/thoughts why RAID 5 performed so well? Or am I misinterpreting the data?
So from this data, should we go with RAID 50 for the faster seek, or RAID 10 like most Splunkers recommend with lower seek but better Sequential block I/O?
I realize all the numbers are above the recommended 800 IOPS but we'd like to select the ideal configuration.
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