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Changing virtual disk failover/failback setting, Implicit lun transition – HP EVA P6000 Storage User Manual

Page 38

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Table 8 Failback settings by operating system (continued)

Supported settings

Default behavior

Operating system

Path A/B – Failover only

Path A/B – Failover/Failback

No preference

Host follows the unit

1

OpenVMS

Path A/B – Failover only

Path A/B – Failover/Failback
(recommended)

No preference

Host follows the unit

1

Oracle Solaris

Path A/B – Failover only

Path A/B – Failover/Failback

No preference

Host follows the unit

1

VMware

Path A/B – Failover only

Path A/B – Failover/Failback

No preference

Failback performed on the host

Windows

Path A/B – Failover only

Path A/B – Failover/Failback

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 38)

identifies the presentation behavior that results when the failover/failback

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

Impact on virtual disk presentation

New setting

None. The disk maintains its original presentation.

No Preference

If the disk is currently presented on Controller 2, it is moved to Controller 1.

Path A Failover

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.

Path B Failover

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.

Path A Failover/Failback

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.

Path B Failover/Failback

If the disk is on Controller 2, it remains there.

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 all versions of XCS.

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P63x0/P65x0 EVA operation