Changing Virtual Disk Failover/Failback Setting; Implicit Lun Transition - HP EVA P6000 User Manual

Table 8 Failback settings by operating system (continued)
Operating system
OpenVMS
Oracle Solaris
VMware
Windows
1
If preference has been configured to ensure a more balanced controller configuration, the Path A/B –Failover/Failback
setting is required to maintain the configuration after a single controller reboot.

Changing virtual disk failover/failback setting

Changing the failover/failback setting of a virtual disk may impact which controller presents the
disk. Table 9 (page 37)
setting for a virtual disk is changed.
NOTE: If the new setting moves the presentation of the virtual disk to a new controller, any
snapshots or snapclones associated with the virtual disk are also moved.
Table 9 Impact on virtual disk presentation when changing failover/failback setting
New setting
No Preference
Path A Failover
Path B Failover
Path A Failover/Failback
Path B Failover/Failback

Implicit LUN transition

Implicit LUN transition automatically transfers management of a virtual disk to the array controller
that receives the most read requests for that virtual disk. This improves performance by reducing
the overhead incurred when servicing read I/Os on the non-managing controller. Implicit LUN
transition is enabled in VCS 4.xxx and all versions of XCS.
When creating a virtual disk, one controller is selected to manage the virtual disk. Only this
managing controller can issue I/Os to a virtual disk in response to a host read or write request. If
Default behavior
Host follows the unit
Host follows the unit
Host follows the unit
Failback performed on the host
identifies the presentation behavior that results when the failover/failback
Impact on virtual disk presentation
None. The disk maintains its original presentation.
If the disk is currently presented on Controller 2, it is moved to Controller
1. If the disk is on Controller 1, it remains there.
If the disk is currently presented on Controller 1, it is moved to Controller
2. If the disk is on Controller 2, it remains there.
If the disk is currently presented on Controller 2, it is moved to Controller
1. If the disk is on Controller 1, it remains there.
If the disk is currently presented on Controller 1, it is moved to Controller
2. If the disk is on Controller 2, it remains there.
Supported settings
Path A/B – Failover only
Path A/B – Failover/Failback
1
No preference
Path A/B – Failover only
Path A/B – Failover/Failback
(recommended)
1
No preference
Path A/B – Failover only
Path A/B – Failover/Failback
1
No preference
Path A/B – Failover only
Path A/B – Failover/Failback
No preference
Path A/B – Failover only
Path A/B – Failover/Failback
Operating tips and information 37