It is used on a mounted pool to discard (or trim) blocks which are not in use by the pool. You must use this option only on thin-provisioned storage devices.
nlvm [nlvm_options] fstrim pool <pool_name>
Command Option
Mandatory. Specify the name of the NSS pool.
Example
MYPOOL1
Command Examples
Trims the unused blocks in the NSS pool named MYPOOL1 and then displays the trimmed size in bytes.
Trims the unused blocks in the NSS pool named MYPOOL1 asynchronously. For more information on the trimmed size in bytes, see logs at /var/log/messages.