Table of Contents
For details on the horctakeover command, see Hitachi AMS Command
Control Interface (CCI) Reference Guide (MK-97DF8121).
Swapping P-VOL and S-VOL
SWAP Takeover ensures that system operation continues by reversing the
characteristics of the P-VOL and the S-VOL and swapping the relationship
between the P-VOL and S-VOL. After S-VOL takeover, host operations
continue on the S-VOL, and S-VOL data becomes updated as a result of I/
O operations. When continuing application processing using the S-VOL or
when restoring application processing to the P-VOL, the swap function
makes the P-VOL up-to-date, by reflecting updated data on the S-VOL to
the P-VOL.
Failback to the local array
The fallback process involves restarting business operations at the local site.
The following shows the procedure after the pair swap is performed.
1. On the remote array, after S-VOL takeover and the TCE pair swap
command are executed, the S-VOL is mounted, and data restoration is
executed (fsck for UNIX and chkdsk for Windows).
2. I/O is restarted using the S-VOL.
3. When the local site/array is restored, the TCE pair is created from the
remote array. At this time, the S-VOL is located on the local array.
4. After the initial copy is completed and status is Paired, I/O to the remote
TCE volume is stopped and it is unmounted.
5. The TCE pair is split. This completes transfer of data from the remote
volume to the local volume.
6. At the local site, the pair swap command is issued. When this is
completed, the S-VOL in the local array becomes the P-VOL.
7. Mount the new P-VOL on the local array is mounted and I/O is restarted.
8–12
Hitachi AMS 2000 Family TrueCopy Extended Distance User Guide
Example scenarios and procedures
Table of Contents
Troubleshooting
