HP XP7 for Compatible FlashCopy Mirroring User Guide (TK940-96001)

NOTE: Consider the following important points when using external volumes with Compatible
FlashCopy:
• 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 a Compatible FlashCopy relationship to which attributes are set by
other products.
Table 6 Reverse Restore and Fast Reverse Restore when a Compatible FlashCopy volume is used
as volume of other products
Compatible FlashCopy SE VolumeCompatible FlashCopy
Volume
Products
T-VOL (TSE-VOL)S-VOLT-VOLS-VOL
----Protect attributeVolume
Retention
OKOKOKOKRead enabled/Write disabled
attribute
OKOKOKOKRead/Write enabled attribute
-OKOKOKCache Residency
-OKOKOKExternal Storage
-OKOKOKThin Provisioning Z
-OKOKOKSmart Tiers Z
OKOKOKOKParallel Access Volumes
----Auto LUN
The following volumes cannot be used as the S-VOL or the T-VOL of a Compatible FlashCopy
relationship:
• Command devices used by Business Continuity Manager
• Journal volumes of Continuous Access Journal Z
• Alias volumes used by Parallel Access Volumes feature
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 27