Question Re: DB2 backup query in Technology Q&A

DB2 backup query

Former Member — Fri, 18 Nov 2011 10:50:36 GMT

In DBACOCKPIT, the database backup section is empty although a DB online backup has run last night. Till yesterday, it was visible. When I check from DB2 Level using db2 LIST HISTORY BACKUP SINCE 20111117 FOR XXX, it returns no matching entries. However surprisingly, when I issue db2 get snapshot for db on XXX, it does state that there was a backup run on 17th with the exact same timestamp as the SAP background job time stamp. The backup runs as Backup ground job with an OS command db2 backup database DB online to tape via netbackup utilities. I am wondering what could be the problem here. Another point to note here is this applies only to the database backup, there is no problem with the log file backup as I can see them via DB12. May be database and log file backup write to different DB tables.

db2diag.log shows backup run as per schedule.

Parameters num_db_backups is set to 12,rec_his_retentn is 60 and auto_del_rec_obj is not set

Any thoughts how could the db backup history could have been wiped out. Are there any other command utilities that can delete the history interactively and if so how can I trace it back to it.

One final thing, we have run the online backup without including logs. Do you think this could have any impact at all.

Regards

Kal

Re: DB2 backup query

Former Member — Fri, 18 Nov 2011 11:00:23 GMT

Hello,

>> One final thing, we have run the online backup without including logs. Do you think this could have any impact at all.

This doesn't impact.

Did this problem (backup history wiped out) happen just once or does it happen everyday ?

Any parameter in netbackup utility to check and confirm ? Not sure , I never worked on netbackup.

Thanks

Re: DB2 backup query

Former Member — Fri, 18 Nov 2011 11:15:28 GMT

This has not happened atleast in the last six months and I dont know before that as I was supporting oracle databases before that. It was fine until last night something must have been set off last night and was done probably interactively, not sure how I can track it back to that. Netbackup utilities do not write into the DB2 database actually, the command line just points the backup to be directed to tape.

Regards

Kal

Re: DB2 backup query

Former Member — Fri, 18 Nov 2011 11:22:35 GMT

Not sure if someone had executed db2 prune history.

But this is strange that only the full backup history went away, not the log backup.

Let's scan db2diag.log once more to see something latest.

Thanks

Re: DB2 backup query

Former Member — Tue, 22 Nov 2011 06:59:45 GMT

May be you are right....upon looking at the diag log further, I found the following

FUNCTION: DB2 UDB, Automatic Table Maintenance, AtmTable::runstats, probe:900

...skipping...

FUNCTION: DB2 UDB, database application extension for utili, adminListHist, probe:301

DATA #1 : <preformatted>

The recovery history file has been pruned since this

query began. Query stopped.

Looks the automatic stats job has pruned the history file. But the ibm help says, the most recent full database backup plus its restore set will always be kept, unless you use the PRUNE utility with the FORCE option. I am wondering how Automatic table maintenance uses force in this equation. Do you know any inherent setting within the Automatic Table Maintenance that controls this besides the actual DB2 parameters NUM_DB_BACKUPS and REC_HIS_RETENTN

Regards

Kal

Re: DB2 backup query

Former Member — Tue, 22 Nov 2011 07:00:02 GMT

May be you are right....upon looking at the diag log further, I found the following

FUNCTION: DB2 UDB, Automatic Table Maintenance, AtmTable::runstats, probe:900

...skipping...

FUNCTION: DB2 UDB, database application extension for utili, adminListHist, probe:301

DATA #1 : <preformatted>

The recovery history file has been pruned since this

query began. Query stopped.

Regards

Kal