It is possible to remove all state database replicas, but practically speaking, you should never do so while metadevices are still configured. Removing all state database replicas renders metadevices inoperable.
Removing the entry for a state database replica from the md.tab file does not delete the replica from the system. You must use DiskSuite Tool, or run the metadb -d command.
Before deleting the state database replica, make sure that it is no longer needed.