Response Time Of Pairsplit Command - Hitachi AMS 2000 User Manual

When a pair is newly added to the CTG, the pair is synchronized with the
existing cycle timing. In the example, the pair is synchronized with the
existing cycle from the cycle 3 and its status is changed to PAIR from the
cycle 4.
• When the paircreate or pairresync command is executed, the pair
undergoes the differential copy in the COPY status, undergoes the
cyclic copy once, and then placed in the PAIR status. When a new pair
is added to a CTG, which is already placed in the PAIR status, by the
paircreate or pairresync command, the copy operation halts until the
time of the existing cyclic copy after the differential copy is completed.
Further, it is not placed in the PAIR status until the first cyclic copy is
completed after it begins to act in time to the cycle. Therefore, the pair
synchronization rate displayed by Navigator 2 or CCI may be 100% or
not changed when the pair status is COPY.
• When you want to confirm the time from the stop of the copy operation
to the start of the cyclic copy, check the start of the next cycle by
displaying the predicted time of completing the copy using Navigator 2.
For the procedure for displaying the predicted time of completing the
copy, refer to section 5.2.7.

Response time of pairsplit command

A response time of a pairsplit command depends on a pair status and an
option.
In a case of splitting and deleting a pair with PAIR status, a completion of a
processing takes time depending on the amount of differential data at P-
VOL.
In a case of creating a remote snapshot, CCI command returns immediately
but a completion of creating a snapshot depending on the amount of
differential data at P-VOL. In order to check the completion, see Split-
Marker of a remote snapshot is updated or a creation time of a snapshot is
updated.
Hitachi AMS 2000 Family TrueCopy Extended Distance User Guide
Table B-2 summarizes a response time for each CCI command.
Operations using CCI
B–15