There are times when an online
PROBKUP needs to be stopped. These include (although not exclusively) times when a Task Schedule / cron or batch job is runs at set intervals to perform an online backup and the previous instance of the online probkup has not completed. In these cases, the following error message will appear because only
one on-line backup can be made at a time and the backup will exit.
An on-line backup is already active. (1550)
At this stage, killing the pid of the associated online PROBKUP _mprshut process may bring the database down with:
User <number> died with 1 buffers locked. (2523)
Begin ABNORMAL shutdown code (2249)
Disconnecting dead user <number>. (2527)
If the kill does not bring the database down, the "An on-line backup is already active. (1550)" message will continue to display when subsequent online PROBKUP sessions are run. This is because the userid of the backup process is still registered in the _usrctrl of shared memory.
To stop an online PROBKUP
The following steps will interrupt the existing online PROBKUP process using PROMON:
1. When the
PROBKUP online (from the previous start) is still running, it will be listed in the usrctrl table:
$ promon dbname
> Option 1. User Control
> Option 1. Display all entries
Look for the "
Usr" number that has a "
BKUP" entry in the "
Type" column, example:
Usr Name Type Wait Table Dbkey Trans PID Sem Srv Login Time
6 root BKUP -- 0 0 0 5712 0 0 05/07/14 15:58
2. The online backup process can be stopped by disconnecting the
PROBKUP user:
$ promon dbname
> Option 8. Shut Down Database
> Option 1. Disconnect a User
Enter the Usr number found with the "BKUP" entry in the "Type" column. (Usr# 6 in the example above)
The database lg file will confirm the current online backup has terminated:
User (number) disconnect initiated
Backup cancelled disconnected by server (1726)
All subsequent re-starts (proserve, _mprosrv, dbman) of the database will warn with the following error message until the next
PROBKUP session completes without error:
The last backup was not completed successfully. (1553)
Finding why the online PROBKUP takes longer than usualInvestigation into why the online PROBKUP is taking longer than it normally would includes (but not exclusively):
a) A large bi file - during online probkup, the bi file is included as well, it is time to truncate the bi file and further investigate why the bi file is growing larger than expected.
b) A quiet point being raised by the Database Manager waiting for manual intervention by the Database Administrator, when -aistall or -bistall parameters are configured in the database startup script will stall the current online backup.
c) Rapid Database growth requires larger backup volumes that takes longer to complete - consider running incremental online probkups or increasing the interval between these instances.
d) Resource contention on the server.
e) I/O bound disks.
f) The backup volume destination either becoming unwritable or running out of disk space. This triggers
a "Please enter next device/file name or type "quit" to exit", and while the PROBKUP cannot write all OLTP is stalled. A workaround for this condition is to add an input file to the PROBKUP scripts, which then forces a "quit" and terminates the online backup.
Example:
$ probkup online dbname <path>/dbname.bakup1 -Bp 32 < response.file
# response.file
quit
<CRLF>
