Lustre 1.6 Operations Manual

19.2.2.3 Output of the sbdfilter_survey Script
The summary file and stdout contain lines like:
ost 8 sz 67108864K rsz 1024 obj 8 thr 8 write613.54 [ 64.00, 82.00]
Where:
Variable
Supported Type
ost8
sz 67108864K
rsz 1024
obj 8
thr 8
write
Total number of OSTs under test.
Total amount of data read or written (in KB).
Record size (size of each echo_client I/O).
Total number of objects over all OSTs.
Total number of threads over all OSTs and objects.
Test name; if more tests have been specified, they all appear on the same
line.
613.54 Aggregate bandwidth over all OSTs.
[64, 82.00] Minimum and maximum instantaneous bandwidths on an individual OST.
Note – Although the numbers of threads and objects are specified per-OST in the
customization section of the script, results are reported aggregated over all OSTs.
19.2.2.4 Visualizing Results
It is useful to import the summary data (its fixed width) into Excel (or any graphing
package) and graph the bandwidth against the number of threads for varying
numbers of concurrent regions. This shows how the OSS performs for a given
number of concurrently-accessed objects (files) with varying numbers of
inputs/outputs in flight.
It is also useful to record average disk I/O sizes during each test. These numbers
help find pathologies in the system when the filesystem block allocator or the block
device elevator fragment I/O requests.
The obparse.pl script (included) is an example of processing the output files to a
.csv format.
19-8 Lustre 1.6 Operations Manual • September 2008