CONTAP-573125: Linux and AIX hosts show split path groups for ASA LUNs after a planned takeover
Issue
On an ASA system, a planned takeover can leave a non-Windows host reporting the paths to a LUN in two ALUA groups. ASA LUNs are expected to stay Active/Optimized on every path.
On Linux DM-Multipath, multipath -ll shows one group with priority 50 and status active, and a second group with priority 10 and status enabled. Devices in the first group report active/optimized in /sys/block/<sdX>/device/access_state. Devices in the second group report active/non-optimized. The paths remain in active ready running state. During the takeover itself, an iSCSI path can also be reported failed or faulty.
The split grouping remains through the takeover. In the reported Linux case, about one minute after giveback the LUN returned to a single priority-50 group and every path reported active/optimized.
On AIX, sanlun lun show can list the paths as Primary while lsmpio lists some of those paths as non-optimized after the takeover.
Host I/O continues on the paths that remain Active/Optimized. Paths left Active/Non-Optimized are used at the lower ALUA priority until the host returns them to one group.
On Linux DM-Multipath, multipath -ll shows one group with priority 50 and status active, and a second group with priority 10 and status enabled. Devices in the first group report active/optimized in /sys/block/<sdX>/device/access_state. Devices in the second group report active/non-optimized. The paths remain in active ready running state. During the takeover itself, an iSCSI path can also be reported failed or faulty.
The split grouping remains through the takeover. In the reported Linux case, about one minute after giveback the LUN returned to a single priority-50 group and every path reported active/optimized.
On AIX, sanlun lun show can list the paths as Primary while lsmpio lists some of those paths as non-optimized after the takeover.
Host I/O continues on the paths that remain Active/Optimized. Paths left Active/Non-Optimized are used at the lower ALUA priority until the host returns them to one group.