The Operations Manual contains the following warning:

The obdfilter_survey script is destructive and should not be run on devices that containing existing data that needs to be preserved. Thus, tests using obdfilter_survey should be run before the Lustre file system is placed in production.

However, the tool can be used in a production environment so long as it isn't used in 'manual' mode.

Further, due to the indentation, it isn't clear if this warning and the other notes pertain to the 'Remote file system over the network' section, or for the tool in general.

The same clarification should be made to README.obdfilter-survey in the lustre-iokit.