HP XP7 Storage - Manual (Page 21)

Compatible FlashCopy-to-Continuous Access Journal Z primary volume
function (Compatible FlashCopy only)
The Compatible FlashCopy-to-Cnt Ac-J Z primary volume function enables you to share Compatible
FlashCopy T-VOLs and Cnt Ac-J Z P-VOLs. When you share Compatible FlashCopy T-VOLs and
Cnt Ac-J Z P-VOLs, the status of the Cnt Ac-J Z pairs must be Duplex, Pending duplex, Suspend, or
Suspending. You can create Cnt Ac-J Z pairs after creating Compatible FlashCopy relationships.
You can also create Compatible FlashCopy relationships after creating Cnt Ac-J Z pairs but only
when the following options are used:
•
DFSMSdss: FCTOPPRCPRIMARY
•
TSO: TGTPPRIM (YES)
•
ICKDSF: TGTOKASPPRCPRIM (YES)
•
ANTRQST Macro: TGTPPRIM (YES)
For details about using Compatible FlashCopy with Cnt Ac-J Z, see (page 33) .
The requirements of the Compatible FlashCopy-to-Cnt Ac-J Z primary volume function are as follows:
•
The Continuous Access Journal Z product is required for using the Compatible FlashCopy to
Cnt Ac-J Z primary volume function.
•
The Compatible FlashCopy-to-Cnt Ac-J Z primary volume function can be used regardless of
the status of Cnt Ac-J Z.
•
Data that Compatible FlashCopy copies to Cnt Ac-J Z P-VOLs is transferred to Cnt Ac-J Z S-VOLs
asynchronously. Cnt Ac-J Z displays the progress of this asynchronous data transfer. Depending
on the timing of the Compatible FlashCopy and Cnt Ac-J Z copy operations, a time delay may
occur between the Compatible FlashCopy copy operation and the Cnt Ac-J Z copy operation,
and the Cnt Ac-J Z asynchronous data transfer may progress slowly.
•
If the Compatible FlashCopy S-VOL and T-VOL are both Thin Provisioning Z volumes, the
number of pages remaining in T-VOL may differ depending on the timing.
•
If you create Cnt Ac-J Z pairs or resynchronize suspended pairs when Compatible FlashCopy
relationships exist, Compatible FlashCopy prepares as many copies as the number of
relationships. The larger the number of relationships per volume, the longer it takes for Cnt
Ac-J Z pairs to become Duplex. Even with lower load, it takes approximately 1.5 times as
much time as when the Cnt Ac-J Z pairs are not used with FlashCopy.
When using the Preserve Mirror FlashCopy function, it is recommended that the maximum
number of relationships (or data sets) per volume should be 2000 or less. If that is too difficult,
you should create and operate one relationship for each volume. This causes non-data-set
parts to be copied as well, but the status of the Cnt Ac-S Z pairs will change to Duplex in a
shorter time.
The copy process of Compatible FlashCopy relationships and Cnt Ac-J Z pairs by the Compatible
FlashCopy-to-Cnt Ac-J Z primary volume function is the same as that of the Compatible
FlashCopy-to-PPRC primary volume function.
Preserve mirror Compatible FlashCopy function (Compatible FlashCopy
only)
If a Compatible FlashCopy T-VOL is a Cnt Ac-S Z P-VOL, the FlashCopy to PPRC primary volume
function copies data from the Compatible FlashCopy T-VOL to the Cnt Ac-S Z S-VOL. During this
function’s data copy, the Cnt Ac-S Z pair is in Pending status. If a failure occurs while copying,
the data on the Cnt Ac-S Z S-VOL cannot be guaranteed. The Preserve Mirror Compatible FlashCopy
function allows you to copy the Compatible FlashCopy data to the remote site with the Cnt Ac-S
Z pairs in Duplex status.
Compatible FlashCopy-to-Continuous Access Journal Z primary volume function (Compatible FlashCopy only) 21