The pre-processing and post-processing for a file system is typically the unmounting and remounting of the file system. (For Windows, the processing consists of allocating and canceling a drive letter.) Pre-processing and post-processing of the replication source volume is performed in order to guarantee the replication source data by disabling access from other processes during execution of synchronous processing and snapshot copy.
If no volume is mounted, the pre-processing and post-processing are not performed.
When the replication target volume is a physical disk, the implementation status of the pre-processing and post-processing for a file system is shown below. This table shows whether pre-processing and post-processing are performed depending on the command type. It also shows the copy status at the time of the command execution.
Command | Copy status | Source/Destination | Preprocessing | Post-processing |
|---|---|---|---|---|
swsrpstartsync (Backup synchronous processing start command) | uncopy or replication establishment | Source | X | X |
Destination | O--*1 | X | ||
equivalence maintenance | Source | O | O | |
Destination | X | O--*2 | ||
equivalence maintenance | Source | O | O | |
Destination | X | O--*2 | ||
Replication establishment | Source | X | X | |
Destination | X | X | ||
copying | Source | X | X | |
Destination | X | X | ||
uncopy | Source | O | O | |
Destination | O | O |
O : executed,
X : not executed
The post-processing for the pre-processing executed in step (*1) is executed in step (*2). In the post-processing in (2), re-mount is performed for the mount point where unmount was performed in the pre-processing in (1).
The pre-processing and post-processing for a file system can be customized. The processing is started in accordance with the table above when a replication management command is executed. For replication between servers, these scripts are executed by remote execution using TCP/IP in the pre-processing and post-processing of a volume that is not connected.
The operation image before and after processing is shown in the following figure.
Figure C.1 Synchronized replication processing
If processing other than the standard pre-processing and post-processing is required in the pre-processing and post-processing, customize the scripts.
When customizing a script, strictly observe the following rules regarding error codes:
Error code | Usage |
|---|---|
0-99 | Unusable (reserved for AdvancedCopy Manager) |
100-255 | Usable |
Note
When the replication target is a volume group that includes a logical volume in which the file system has been built, refer to "Replicate a volume group". The pre-processing and post-processing scripts have to be customized to execute unmount/mount processing for all logical volumes in which the file system has been built.
If the replication target volume cannot be unmounted, see "When you do not want to unmount the replication target volume" and customize the script for pre-processing.
AdvancedCopy Manager does not support pre-processing and post-processing of databases. Database pre-processing and post-processing must be executed uniquely before and after (respectively) the execution of the AdvancedCopy Manager command.
