Les périphériques symétriques peuvent permettre de rétablir automatiquement un chemin optimal. Si un basculement se produit sur le chemin initial, le chemin d'accès de réserve devient le nouveau chemin en ligne. Le chemin de réserve est généralement un chemin d'accès moins performant. Lorsque le rétablissement automatique est activé, le chemin initial redevient le chemin en ligne, et le basculement vers le chemin initial s'effectue automatiquement.
# mpathadm list mpath-support mpath-support: libmpscsi_vhci.so
# mpathadm modify mpath-support -a on libmpscsi_vhci.so
# mpathadm show mpath-support libmpscsi_vhci.so mpath-support: libmpscsi_vhci.so Vendor: Sun Microsystems Driver Name: scsi_vhci Default Load Balance: round-robin Supported Load Balance Types: round-robin logical-block Allows To Activate Target Port Group Access: yes Allows Path Override: no Supported Auto Failback Config: 1 Auto Failback: on Failback Polling Rate (current/max): 0/0 Supported Auto Probing Config: 0 Auto Probing: NA Probing Polling Rate (current/max): NA/NA Supported Devices: Vendor: SUN Product: T300 Revision: Supported Load Balance Types: round-robin Vendor: SUN Product: T4 Revision: Supported Load Balance Types: round-robin . . .
Cette opération s'applique uniquement aux périphériques répertoriés dans les deux catégories suivantes :
Périphériques asymétriques dotés d'un mécanisme de basculement propriétaire reconnu et compatible avec la prise en charge de la fonctionnalité multipathing
Périphériques conformes à la prise en charge du groupe de ports cible de norme T10 libmpscsi_vhci.so et fournissant un accès aux unités logiques asymétriques en mode explicite
# mpathadm list lu /dev/rdsk/c0t600144F08069703400004E828EE10004d0s2 Total Path Count: 8 Operational Path Count: 8 /dev/rdsk/c0t600144F08069703400004E8183DF0002d0s2 Total Path Count: 8 Operational Path Count: 8 /dev/rdsk/c0t600A0B800026D63A0000A4994E2342D4d0s2 Total Path Count: 4 Operational Path Count: 4 /dev/rdsk/c0t600A0B800029065C00007CF54E234013d0s2 Total Path Count: 4 Operational Path Count: 4 /dev/rdsk/c0t600A0B800026D63A0000A4984E234298d0s2 Total Path Count: 4 Operational Path Count: 4 . . .
# mpathadm show lu /dev/rdsk/c0t600A0B800026D63A0000A4984E234298d0s2 Logical Unit: /dev/rdsk/c0t600A0B800026D63A0000A4984E234298d0s2 mpath-support: libmpscsi_vhci.so Vendor: SUN Product: CSM200_R Revision: 0660 Name Type: unknown type Name: 600a0b800026d63a0000a4984e234298 Asymmetric: yes Current Load Balance: round-robin Logical Unit Group ID: NA Auto Failback: on Auto Probing: NA Paths: Initiator Port Name: 210000e08b841feb Target Port Name: 200800a0b826d63b Override Path: NA Path State: OK Disabled: no Initiator Port Name: 210000e08b841feb Target Port Name: 200900a0b826d63b Override Path: NA Path State: OK Disabled: no Initiator Port Name: 210000e08b841feb Target Port Name: 200800a0b826d63c Override Path: NA Path State: OK Disabled: no Initiator Port Name: 210000e08b841feb Target Port Name: 200900a0b826d63c Override Path: NA Path State: OK Disabled: no Target Port Groups: ID: 5 Explicit Failover: yes Access State: active Target Ports: Name: 200800a0b826d63b Relative ID: 0 Name: 200800a0b826d63c Relative ID: 0 ID: 15 Explicit Failover: yes Access State: standby Target Ports: Name: 200900a0b826d63b Relative ID: 0 Name: 200900a0b826d63c Relative ID: 0
# mpathadm failover lu /dev/rdsk/c0t600A0B800026D63A0000A4984E234298d0s2
Si cette opération réussit, l'état d'accès aux groupes de ports cible des périphériques change en raison du basculement de l'unité logique.
# mpathadm show lu /dev/rdsk/c0t600A0B800026D63A0000A4984E234298d0s2 Logical Unit: /dev/rdsk/c0t600A0B800026D63A0000A4984E234298d0s2 mpath-support: libmpscsi_vhci.so Vendor: SUN Product: CSM200_R Revision: 0660 Name Type: unknown type Name: 600a0b800026d63a0000a4984e234298 Asymmetric: yes Current Load Balance: round-robin Logical Unit Group ID: NA Auto Failback: on Auto Probing: NA Paths: Initiator Port Name: 210000e08b841feb Target Port Name: 200800a0b826d63b Override Path: NA Path State: OK Disabled: no Initiator Port Name: 210000e08b841feb Target Port Name: 200900a0b826d63b Override Path: NA Path State: OK Disabled: no Initiator Port Name: 210000e08b841feb Target Port Name: 200800a0b826d63c Override Path: NA Path State: OK Disabled: no Initiator Port Name: 210000e08b841feb Target Port Name: 200900a0b826d63c Override Path: NA Path State: OK Disabled: no Target Port Groups: ID: 5 Explicit Failover: yes Access State: standby Target Ports: Name: 200800a0b826d63b Relative ID: 0 Name: 200800a0b826d63c Relative ID: 0 ID: 15 Explicit Failover: yes Access State: active Target Ports: Name: 200900a0b826d63b Relative ID: 0 Name: 200900a0b826d63c Relative ID: 0
Si le chemin d'accès à une unité logique est désactivé, la commande enable permet de le réactiver. Il faut spécifier le chemin complet, incluant le nom du port initiateur, le nom du port cible et l'unité logique. Pour vérifier la modification, exécutez la commande show pour l'unité logique concernée.
# mpathadm list lu /dev/rdsk/c0t600144F08069703400004E828EE10004d0s2 Total Path Count: 8 Operational Path Count: 8 /dev/rdsk/c0t600144F08069703400004E8183DF0002d0s2 Total Path Count: 8 Operational Path Count: 8 /dev/rdsk/c0t600A0B800026D63A0000A4994E2342D4d0s2 Total Path Count: 4 Operational Path Count: 4 /dev/rdsk/c0t600A0B800029065C00007CF54E234013d0s2 Total Path Count: 4 Operational Path Count: 4 /dev/rdsk/c0t600A0B800026D63A0000A4984E234298d0s2 Total Path Count: 4 Operational Path Count: 4 /dev/rdsk/c0t600A0B800029065C00007CF44E233FCFd0s2 Total Path Count: 4 Operational Path Count: 4 . . .
# mpathadm show lu Logical Unit: /dev/rdsk/c0t600A0B800026D63A0000A4984E234298d0s2 mpath-support: libmpscsi_vhci.so Vendor: SUN Product: CSM200_R Revision: 0660 Name Type: unknown type Name: 600a0b800026d63a0000a4984e234298 Asymmetric: yes Current Load Balance: round-robin Logical Unit Group ID: NA Auto Failback: on Auto Probing: NA Paths: Initiator Port Name: 210000e08b841feb Target Port Name: 200800a0b826d63b Override Path: NA Path State: OK Disabled: no Initiator Port Name: 210000e08b841feb Target Port Name: 200900a0b826d63b Override Path: NA Path State: OK Disabled: no Initiator Port Name: 210000e08b841feb Target Port Name: 200800a0b826d63c Override Path: NA Path State: OK Disabled: no Initiator Port Name: 210000e08b841feb Target Port Name: 200900a0b826d63c Override Path: NA Path State: OK Disabled: no Target Port Groups: ID: 5 Explicit Failover: yes Access State: standby Target Ports: Name: 200800a0b826d63b Relative ID: 0 Name: 200800a0b826d63c Relative ID: 0 ID: 15 Explicit Failover: yes Access State: active Target Ports: Name: 200900a0b826d63b Relative ID: 0 Name: 200900a0b826d63c Relative ID: 0
# mpathadm enable path -i 210000e08b841feb -t 200900a0b826d63b \ -l /dev/rdsk/c0t600A0B800026D63A0000A4984E234298d0s2
Cette opération désactive les chemin d'accès à l'unité logique, quel que soit son état de fonctionnement.
# mpathadm list lu /dev/rdsk/c0t600144F08069703400004E828EE10004d0s2 Total Path Count: 8 Operational Path Count: 8 /dev/rdsk/c0t600144F08069703400004E8183DF0002d0s2 Total Path Count: 8 Operational Path Count: 8 /dev/rdsk/c0t600A0B800026D63A0000A4994E2342D4d0s2 Total Path Count: 4 Operational Path Count: 4 /dev/rdsk/c0t600A0B800029065C00007CF54E234013d0s2 Total Path Count: 4 Operational Path Count: 4 /dev/rdsk/c0t600A0B800026D63A0000A4984E234298d0s2 Total Path Count: 4 Operational Path Count: 4 /dev/rdsk/c0t600A0B800029065C00007CF44E233FCFd0s2 Total Path Count: 4 Operational Path Count: 4 . . .
# mpathadm show lu /dev/rdsk/c0t600A0B800029065C00007CF34E233F89d0s2 Logical Unit: /dev/rdsk/c0t600A0B800029065C00007CF34E233F89d0s2 mpath-support: libmpscsi_vhci.so Vendor: SUN Product: CSM200_R Revision: 0660 Name Type: unknown type Name: 600a0b800029065c00007cf34e233f89 Asymmetric: yes Current Load Balance: round-robin Logical Unit Group ID: NA Auto Failback: on Auto Probing: NA Paths: Initiator Port Name: 210000e08b841feb Target Port Name: 200800a0b826d63b Override Path: NA Path State: OK Disabled: no Initiator Port Name: 210000e08b841feb Target Port Name: 200900a0b826d63b Override Path: NA Path State: OK Disabled: no Initiator Port Name: 210000e08b841feb Target Port Name: 200800a0b826d63c Override Path: NA Path State: OK Disabled: no Initiator Port Name: 210000e08b841feb Target Port Name: 200900a0b826d63c Override Path: NA Path State: OK Disabled: no Target Port Groups: ID: 8 Explicit Failover: yes Access State: standby Target Ports: Name: 200800a0b826d63b Relative ID: 0 Name: 200800a0b826d63c Relative ID: 0 ID: 18 Explicit Failover: yes Access State: active Target Ports: Name: 200900a0b826d63b Relative ID: 0 Name: 200900a0b826d63c Relative ID: 0
# mpathadm disable path -i 210000e08b841feb -t 200900a0b826d63b \ -l /dev/rdsk/c0t600A0B800029065C00007CF34E233F89d0s2