Rman purging issue

Posted by Sumair on Jun 27, 2016; 7:46am
URL: http://erman-arslan-s-oracle-forum.124.s1.nabble.com/Rman-purging-issue-tp1089.html

Dear Erman,

we have two types of rman backups.

i) Daily rman backups run through rman scripts to local mount point.

saturday to thursday (daily) in /backup/rmanbackups and friday (weekly) backup in /backup/fribackup/
location on local mount point.

ii) daily rman backups from saturday to thursday directly from data protector on tapes.


now talking about the rman backups on local mount point.

below are the configurations for rman
RMAN> show all;

RMAN configuration parameters for database with db_unique_name SCC are:
CONFIGURE RETENTION POLICY TO REDUNDANCY 2;
CONFIGURE BACKUP OPTIMIZATION OFF; # default
CONFIGURE DEFAULT DEVICE TYPE TO DISK; # default
CONFIGURE CONTROLFILE AUTOBACKUP ON;
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '/backup/scc/rma                                                                                                                     nbackups/%F';
CONFIGURE DEVICE TYPE DISK PARALLELISM 2 BACKUP TYPE TO BACKUPSET;
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE CHANNEL 1 DEVICE TYPE DISK FORMAT   '/backup/scc/rmanbackups/%U' CONNECT '*';
CONFIGURE CHANNEL 2 DEVICE TYPE DISK FORMAT   '/backup/scc/rmanbackups/%U' CONNECT '*';
CONFIGURE MAXSETSIZE TO UNLIMITED; # default
CONFIGURE ENCRYPTION FOR DATABASE OFF; # default
CONFIGURE ENCRYPTION ALGORITHM 'AES128'; # default
CONFIGURE COMPRESSION ALGORITHM 'BASIC' AS OF RELEASE 'DEFAULT' OPTIMIZE FOR LOAD TRUE ; # default
CONFIGURE ARCHIVELOG DELETION POLICY TO NONE; # default
CONFIGURE SNAPSHOT CONTROLFILE NAME TO '+DATA/snapcf_SCC.f';
CONFIGURE SNAPSHOT CONTROLFILE NAME TO '+DATA/snapcf_scc.f';

We used to purge the obsolete through the below command every thursday

run
{
allocate channel ch01 DEVICE type DISK;
allocate channel ch02 DEVICE type DISK;
allocate channel ch03 DEVICE type DISK;
allocate channel ch04 DEVICE type DISK;
DELETE OBSOLETE DEVICE TYPE DISK;
release channel ch01;
release channel ch02;
release channel ch03;
release channel ch04;
}


when we used to delete the obsolete backups using the above
it used to purge the old backups and free up space up to 1.6 TB on 2 TB mount point.
generally the size of daily rman backup is approximately 200gb.

since two weeks we see something is inappropriate while purging the backups.

now when we purge the backups it doesnt free up the space. we see many pieces on the backup location.

my question is why it(rman pieces) are not considered as obsolete by rman though its several days old.

when we query report obsolete, it doesnt list those pieces in the output which are lying physically on the disk. because of this it is not purging appropriately and could make enough free space on the mount point.

we dont see any errors while purging the obsolete backups, it is just it doesnt list all the pieces as obsolete.

now we have to purge every two three days as it is not releasing space.

ex: when i purge the obsolete on Wednesday or Thursday  it used to purge all the pieces  of previous friday. now we see that only some of the pieces are considered as obsolete and the rest of the pieces are still there.

Please need your expert advise on this issue.