When data loss can occur if the change_fsid option is enabled
Ensure that you have a good understanding of when data loss can occur before you disable the change_fsid option. Disabling this option can create a seamless takeover for clients in the event of a disaster, but there is potential for data loss.
If both the ISLs between the two sites in a fabric MetroCluster go offline, then both the systems remain operational. However, in that scenario, client data is written only to the local plex and the plexes become unsynchronized.
If, subsequently, a disaster occurs at one site, and the cf forcetakeover -d command is issued, the remote plex that survived the disaster is not current. With the change_fsid option set to off, clients switch to the stale remote plex without interruption.
If the change_fsid option is set to on, the system changes the fsids when the cf forcetakeover -d command is issued so clients are forced to remount their volumes and check the integrity of the data before proceeding.