It is any arbitrary string up to 255 characters long. The label of the desired dump session can be copied from the inventory display produced by the -I option. The options are specified just as they would appear if typed into the command line. The options are placed before all options actually given on the command line, just after the command name. Only one -O option can be used.
Recursive use is ignored.
Force completion of an interrupted restore session. This option is required to work around one specific pathological scenario. When restoring a dump session which was interrupted due to an EOM condition and no online session inventory is available, xfsrestore cannot know when the restore of that dump session is complete. The operator is forced to interrupt the restore session. The operator must tell xfsrestore to consider the base restore complete by using this option when applying the resumed dump.