Unusual Use of the RMAN uncatalog Command

A fresh year is the perfect time to learn something new. Recently, I have come across warning messages in the RMAN level 0 backup log file and this post describes how I dealt with them.

The file contents went as follows:

RMAN-06207: WARNING: 1 objects could not be deleted for DISK channel(s) due
RMAN-06208:          to mismatched status.  Use CROSSCHECK command to fix status
RMAN-06210: List of Mismatched objects
RMAN-06211: ==========================
RMAN-06212:   Object Type   Filename/Handle
RMAN-06213: --------------- ---------------------------------------------------
RMAN-06214: Datafile Copy   +RECOC1/prod/snapcf_prod.f


specification does not match any backup in the repository

We took disk-level backups without a recovery catalog schema and the associated command failed with this error: “delete noprompt expired backup;”. So, I executed the commands like “crosscheck backup;” and “crosscheck copy;” but found no expired records. Finally, the control file copy pieces showed validation failed messages as follows:

RMAN> crosscheck copy of controlfile;

released channel: ORA_DISK_1
released channel: ORA_DISK_2
released channel: ORA_DISK_3
released channel: ORA_DISK_4
released channel: ORA_DISK_5
released channel: ORA_DISK_6
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=5663 instance=PROD2 device type=DISK
allocated channel: ORA_DISK_2
channel ORA_DISK_2: SID=6290 instance=PROD2 device type=DISK
allocated channel: ORA_DISK_3
channel ORA_DISK_3: SID=6601 instance=PROD2 device type=DISK
allocated channel: ORA_DISK_4
channel ORA_DISK_4: SID=6915 instance=PROD2 device type=DISK
allocated channel: ORA_DISK_5
channel ORA_DISK_5: SID=325 instance=PROD2 device type=DISK
allocated channel: ORA_DISK_6
channel ORA_DISK_6: SID=631 instance=PROD2 device type=DISK
validation failed for control file copy
control file copy file name=/backups/PROD/snapcf_prod.f RECID=60 STAMP=1025510159
Crosschecked 1 objects

validation failed for control file copy
control file copy file name=+RECOC1/prod/snapcf_prod.f RECID=65 STAMP=1055956089
Crosschecked 1 objects

So, I started the delete command with the “force” option, which was executed successfully. But I still saw those pieces in the list command as follows:

RMAN> delete force expired copy of controlfile;

released channel: ORA_DISK_1
released channel: ORA_DISK_2
released channel: ORA_DISK_3
released channel: ORA_DISK_4
released channel: ORA_DISK_5
released channel: ORA_DISK_6
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=5663 instance=PROD2 device type=DISK
allocated channel: ORA_DISK_2
channel ORA_DISK_2: SID=6290 instance=PROD2 device type=DISK
allocated channel: ORA_DISK_3
channel ORA_DISK_3: SID=6601 instance=PROD2 device type=DISK
allocated channel: ORA_DISK_4
channel ORA_DISK_4: SID=6915 instance=PROD2 device type=DISK
allocated channel: ORA_DISK_5
channel ORA_DISK_5: SID=325 instance=PROD2 device type=DISK
allocated channel: ORA_DISK_6
channel ORA_DISK_6: SID=631 instance=PROD2 device type=DISK
List of Control File Copies
===========================

Key     S Completion Time Ckp SCN    Ckp Time
------- - --------------- ---------- ---------------
65      X 08-NOV-20       281674038070 08-NOV-20
        Name: +RECOC1/prod/snapcf_prod.f
        Tag: TAG20201108T170807

60      X 28-NOV-19       253807915757 28-NOV-19
        Name: /backups/PROD/snapcf_prod.f
        Tag: TAG20191128T075552


Do you really want to delete the above objects (enter YES or NO)? YES
deleted control file copy
control file copy file name=/backups/PROD/snapcf_prod.f RECID=60 STAMP=1025510159
Deleted 1 EXPIRED objects

deleted control file copy
control file copy file name=+RECOC1/prod/snapcf_prod.f RECID=65 STAMP=1055956089
Deleted 1 EXPIRED objects

RMAN> list copy of controlfile;

List of Control File Copies
===========================

Key     S Completion Time Ckp SCN    Ckp Time
------- - --------------- ---------- ---------------
65      X 08-NOV-20       281674038070 08-NOV-20
        Name: +RECOC1/prod/snapcf_prod.f
        Tag: TAG20201108T170807

60      X 28-NOV-19       253807915757 28-NOV-19
        Name: /backups/PROD/snapcf_prod.f
        Tag: TAG20191128T075552

The individual delete commands were failing with “RMAN-06159: error while looking up backup set,” which is expected as these backup pieces are no longer available. To my surprise, the ‘change..uncatalog’ option helped here:

RMAN> delete backupset 65;

using channel ORA_DISK_1
using channel ORA_DISK_2
using channel ORA_DISK_3
using channel ORA_DISK_4
using channel ORA_DISK_5
using channel ORA_DISK_6
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of delete command at 01/02/2022 21:10:34
RMAN-20215: backup set not found
RMAN-06159: error while looking up backup set

RMAN> delete backupset 60;

using channel ORA_DISK_1
using channel ORA_DISK_2
using channel ORA_DISK_3
using channel ORA_DISK_4
using channel ORA_DISK_5
using channel ORA_DISK_6
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of delete command at 01/02/2022 21:10:55
RMAN-20215: backup set not found
RMAN-06159: error while looking up backup set

RMAN> change controlfilecopy  '/backups/PROD/snapcf_prod.f' uncatalog;

uncataloged control file copy
control file copy file name=/backups/PROD/snapcf_prod.f RECID=60 STAMP=1025510159
Uncataloged 1 objects

RMAN> change controlfilecopy tag 'TAG20201108T170807' uncatalog;

uncataloged control file copy
control file copy file name=+RECOC1/prod/snapcf_prod.f RECID=65 STAMP=1055956089
Uncataloged 1 objects

RMAN> crosscheck copy of controlfile;

released channel: ORA_DISK_1
released channel: ORA_DISK_2
released channel: ORA_DISK_3
released channel: ORA_DISK_4
released channel: ORA_DISK_5
released channel: ORA_DISK_6
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=638 instance=PROD2 device type=DISK
allocated channel: ORA_DISK_2
channel ORA_DISK_2: SID=6290 instance=PROD2 device type=DISK
allocated channel: ORA_DISK_3
channel ORA_DISK_3: SID=4726 instance=PROD2 device type=DISK
allocated channel: ORA_DISK_4
channel ORA_DISK_4: SID=6286 instance=PROD2 device type=DISK
allocated channel: ORA_DISK_5
channel ORA_DISK_5: SID=6606 instance=PROD2 device type=DISK
allocated channel: ORA_DISK_6
channel ORA_DISK_6: SID=6915 instance=PROD2 device type=DISK
specification does not match any control file copy in the repository

RMAN> list copy of controlfile;

specification does not match any control file copy in the repository

I usually use this ‘change..uncatalog’ command while cloning/refreshing a database. So, this new usage clause was very surprising. I discovered more about this command from this URL:

https://docs.oracle.com/en/database/oracle/oracle-database/19/bradv/maintaining-rman-backups.html

I hope you found this post helpful. 

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