Lustre 1.6 Operations Manual

19.2.3 ost_survey
The ost_survey tool is a shell script that uses lfs setstripe to perform I/O
against a single OST. The script writes a file (currently using dd) to each OST in the
Lustre filesystem, and compares read and write speeds. The ost_survey tool is
used to detect misbehaving disk subsystems.
Note – We have frequently discovered wide performance variations across all LUNs
in a cluster.
To run the ost_survey script, supply a file size (in KB) and the Lustre mount point.
For example, run:
$ ./ost-survey.sh 10 /mnt/lustre
Average read Speed: 6.73
Average write Speed: 5.41
read - Worst OST indx 0 5.84 MB/s
write - Worst OST indx 0 3.77 MB/s
read - Best OST indx 1 7.38 MB/s
write - Best OST indx 1 6.31 MB/s
3 OST devices found
Ost index 0 Read speed 5.84 Write speed 3.77
Ost index 0 Read time 0.17 Write time 0.27
Ost index 1 Read speed 7.38 Write speed 6.31
Ost index 1 Read time 0.14 Write time 0.16
Ost index 2 Read speed 6.98 Write speed 6.16
Ost index 2 Read time 0.14 Write time 0.16
Chapter 19 Lustre I/O Kit 19-9