General Information; Planned Outage Of The Primary System; Planned Outage Of The Secondary System Or Remote Path - Hitachi G200 User Manual

General information

Please review the following system behaviors regarding powering off:
• TC pairs are not affected when power is removed from a primary system
while operations are in progress.
• When power is restored on the primary system, the system
communicates with the secondary systems to confirm S-VOL pair
status(es). Make sure that TC communications are fully restored (all
paths have normal status) before beginning I/O operations to the P-VOL.
If the primary system accepts an I/O for a P-VOL before this, all
communications are restored, and the primary system splits the pair and
changes P-VOL status to PSUE-by Remote Storage System. The primary
system cannot change the pair status of the S-VOL.
• If power is removed from a secondary system or from a data path
component while TC operations are in progress, the primary system
detects the communication failure, splits all affected pairs, and generates
SIMs reporting the failures. The primary system changes the P-VOL status
to PSUE-by Remote Storage System but cannot change the status of the
S-VOLs.
• If a primary is powered off and the backup batteries are fully discharged
while pairs are split, differential data is retained to SSD. In this unlikely
case, the primary system copies differential data to the secondary system
when the pairs are resynchronized.

Planned outage of the primary system

A planned outage of the primary system does not affect TrueCopy.

Planned outage of the secondary system or remote path

You must split the pairs in a secondary system prior to a planned outage of
the system or to a data path component (for example, switch, channel
extender).
To perform a planned outage of a secondary system or data path
component
1 Identify the P-VOLs that are paired with S-VOL in the secondary system
.
that is to be powered off.
For data path outage, identify all P-VOLs in the primary system that use
the path or component to be powered off.
You need to know the primary system, CU, and ID (Port, Host Group ID
or iSCSI Target ID, LUN) for each of the P-VOLs.
2 Connect to each primary system that contains affected P-VOLs, and split
.
all affected pairs. Confirm the changed pair status.
3 Perform the planned outage of the secondary system or data path.
.
4 When the secondary system is fully powered on and ready, resynchronize
.
the affected pairs at each primary system. Confirm the pair status
changes.
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Hitachi TrueCopy® User Guide for Hitachi Virtual Storage Platform Gx00 and Fx00 Models
Monitoring and maintaining the TC system