Required attributes of LUNs for DMP devices
When the
reserve_policy=single_path and reserve_lock=yes, the SCSI-2 reserve may be placed on the device, which affects I/O load balancing and performance. To prevent the impact to load balancing and performance, set the reserve_policy=no_reserve and reserve_lock=no for the devices that are managed by DMP.
These settings are also required for a cluster set-up.
Set the following attributes for LUNs
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Set the following attributes:
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If the path has the
reserve_policyattribute set, change thereserve_policyattribute tono_reservefor all the paths.\# lsattr -E1 hdisk557 | grep res
reserve_policy single_path
Reserve Policy True\# chdev -l hdisk557 -a reserve_policy=no_reserve -P
hdisk557 changed
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If the path has the
reserve_lockattribute set, change thereserve_lockattribute tono.\# lsattr -E1 hdisk558 | grep reserve_lock
reserve_lock yes
Reserve Device on open True\# chdev -l hdisk558 -a reserve_lock=no -P
hdisk558 changed
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Reboot the system for the changes to take effect.