During the backup and restore process, you may need to change tape volumes. If the Backup Server detects a problem with the currently mounted volume, it requests a volume change by sending messages to either the client or its operator console. After mounting another volume, the operator notifies the Backup Server by executing sp_volchanged on Adaptive Server.
On UNIX systems, the Backup Server requests a volume change when the tape capacity has been reached. The operator mounts another tape and then executes sp_volchanged (see Table 12-2).
Sequence |
Operator using isql |
Adaptive Server |
Backup Server |
|---|---|---|---|
1 |
Issues the dump database command |
||
2 |
Sends dump request to Backup Server |
||
3 |
Receives dump request message from Adaptive Server Sends message for tape mounting to operator Waits for operator’s reply |
||
4 |
Receives volume change request from Backup Server Mounts tapes Executes sp_volchanged |
||
5 |
Checks tapes If tapes are okay, begins dump When tape is full, sends volume change request to operator |
||
6 |
Receives volume change request from Backup Server Mounts tapes Executes sp_volchanged |
||
7 |
Continues dump When dump is complete, sends messages to operator and Adaptive Server |
||
8 |
Receives message that dump is complete Removes and labels tapes |
Receives message that dump is complete Releases locks Completes the dump database command |
