Cette commande 'mirror_switch_roles' permet de basculer le statut des volumes d'un couple de réplication.
La syntaxe est la suivante :
mirror_switch_roles <vol=NomVolume | cg=NomCG>
Exemple depuis l'interface Xcli :
# mirror_switch_roles vol=datavg_01
# mirror_switch_roles cg=OracleCGserveur1
(Si plusieurs disques doivent conserver leur cohérence, if faut les placer dans un CG).
Ci-dessous l'extrait de la documentation officielle IBM, en anglais.
Switching Roles between Master and Slave
Switches roles between master and slave volumes.
mirror_switch_roles <vol=VolName | cg=cgName>
|vol||Object name||Local volume name.||N|
|cg||Object name||Local CG name||N|
This command switches between the roles of the master and the slave volumes.
The command can only be issued if coupling is operational and only on the master. Also, for synchronous mirroring it can only be issued when the coupling is synchronized; for asynchronous mirroring it can only be issued if there are no outstanding sync jobs and the volume and its last_replicated snapshot are identical.
- The volume that was previously the master becomes the slave
- The volume that was previously the slave becomes the master
Before this command switches roles, the system stops accepting new writes to the local volume. With synchronous mirrors the system will perform all pending writes, and only after all pending writes have been committed, the roles are switched.
After the command is executed, the coupling is deactivated and the user has to activate it in order to restart synchronization. It is advised to create a snapshot before deactivating the coupling in order to enable recovery from logical errors due to incorrect server configurations.