HP P9000 for Compatible FlashCopy Mirroring User Guide (AV400-96388, October 2011)

• External volumes are the volumes in the external storage system that are mapped as the internal
volumes. For details about External Storage and external volumes, see the HP P9000 External
Storage for Open and Mainframe Systems User Guide.
• If an external volume is specified as a Compatible FlashCopy T-VOL, be careful about the
setting of the time of path blockade watch, which is the time from when the external storage
system is disconnected to when the path is blocked. If the time of path blockade watch set for
the T-VOL is longer than the time of the MIH (Missing Interrupt Handler) timer which is set for
the S-VOL on the host side, MIH may occur on the S-VOL and the processing may end
abnormally when the external storage system is powered off or when failures occur.
• If the host I/O to the S-VOL is more important than the host I/O to the T-VOL, make sure that
the time of the path blockade watch for the T-VOL is smaller than the time of the MIH timer,
which is set for the S-VOL. In this way, the Compatible FlashCopy relationship will be suspended
when the T-VOL is blocked because of the path blockade watch, therefore the host I/O to the
S-VOL can be maintained.
• If the host I/O to the T-VOL and the T-VOL data are more important than the host I/O to the
S-VOL, use the default setting of the path blockade watch for the external volume that is to be
specified as the T-VOL.
The following table describes whether you can perform Reverse Restore and Fast Reverse Restore
on the S-VOL or the T-VOL of Compatible FlashCopy pair to which attributes are set by other
solutions.
Table 6 Whether reverse restore and fast reverse restore can be used when compatible FlashCopy
volume is used as volume of other solutions
Compatible FlashCopy VolumeAttributeSolutions
T-VOLS-VOL
This attribute cannot be set.This attribute cannot be set.ProtectVolume Retention
OKOKRead only
OKOKRead/Write
This setting cannot be made.This setting cannot be made.Security setting that
disables the volume for
use as S-VOL
Volume Security for
Mainframe
OKOKExternal VolumeExternal Storage
OKOK-Thin Provisioning Z
The following volumes cannot be used as the S-VOL or the T-VOL of a Compatible FlashCopy pair:
• Command devices that are used by Business Continuity Manager.
• Journal volumes of Continuous Access Journal Z.
• Reserve volumes used by Business Copy Z.
• Alias volumes that are used by the Parallel Access Volumes.
• System disks.
Using Compatible FlashCopy with Business Copy Z
The following figure shows an example of combining Compatible FlashCopy with Business Copy
Z.
Interoperability With Other products and functions 21