RMAN-06025 - rman keep asking for different logs during recovery

-
After the restore of rman backup the recover session might return errors similar to below,


This is  a common scenario but still it seems there are difficulties in understanding the reason why rman is asking for more logs. 
So when rman complains on set of missing logs, find the oldest log it is asking and check the first_time/next_time values of particular log from (g)v$archived_log. 
If the value returned is older than the restored control file time (select checkpoint_time from v$datafile) and between the backup start time, it is required to provide a valid backup of the archive log or in a situation where backup is not available consider opening the database with inconsistencies.

In the scenario shown in above image, the minimum log rman was asking was sequence 777682 of thread 1. For this sequence this was a archive log generated at 11.10 AM 26th July while the controlfile restored was from 11.50 AM 26th July. So we need to provide the correct backup. Depending on the backup methods used, there can be multiple reasons why particular archive log backup is unknown to the restored control file.

In above case, simply the tape backup that contained the backup of sequence 777682 of thread 1 was generated on 27th July. So there is noway restored control file to be aware on that backup. To find out the required backup we need to query the the backup source/ rman catalog for particular log (rman> list backup of archivelog sequence 777682 thread 1;) and restore the backup, catalog the log file and the restart the recovery.

Another scenario is, when checking the time of the archivelog it can be older than the backup start time. Related to above instance, if rman is asking for a log on 24th July where as the backup started time is 26th July, we need to check the consistency of restored datafile. The easiest way is to query the v$datafile_header.
 select file#, name, status, error, recover, checkpoint_change#, checkpoint_time from v$datafile_header order by CHECKPOINT_TIME desc;
Related to the example, some datafiles were from 24th July while remaining set was from 26th July (Correct restore time). Hence rman is looking for old archivelog backups. Again there can be multiple scenarios why restore was from two different timelines, common culprits being rman skipping in to older backup sets due to unavailability of more recent. Looking at the restore log would always provide clues on the reason.

In above scenario depending on the situation either provide the backups of these old archivelogs or complete the restore from correct backup so the datafiles are consistent (checkpoint_time of datafile header is aligned with checkpoint_time of v$datafile)

Comments

Post a Comment

Popular posts from this blog

ORA-16433: The database or pluggable database must be opened in read/write

-
Image
ORA-16433 is an error returned when a database cannot be opened. This can be a result of multiple conditions including, The inconsistency of the database Physical corruption Loss of dependent files or access issues etc.. More often than not the solution is to recover from available backups, but there can be situations where backups are not available, specially on UAT or Test setups. Although not the ideal scenario, in this type of situation you might want to open the databases even with inconsistency.  In Comes --> _ALLOW_RESETLOGS_CORRUPTION First, if you are in a position to use _ALLOW_RESETLOGS_CORRUPTION=TRUE, that means it has to be a critical moment, and when you come across more ora- errors while you are trying to reopen the databsae, that can be annoying. Note - _ALLOW_RESETLOGS_CORRUPTION=TRUE must only be used after Oracle support confirmation as a last resort. Also make sure to take cold backup before proceeding. Basic steps to be followed to resolve ORA 16433 after
Read more

Oracle Multitenant - Create new service for PDB using DBMS_SERVICE

-
Image
When an Oracle PDB is created it starts up a default service with the PDB name. For direct connections to    PDB this service can be used. But there are situations where new service name is required in PDB level, common example is after a PDB restoration/clone, in order to enable application connections without changes in connection string. Setting service_names parameter in PDB level is not possible hence it is not an option in multitenant setup. How to create a new PDB service on Oracle 12C Check the current services, here only the default service is running, SQL> show pdbs; CON_ID CON_NAME OPEN MODE RESTRICTED ---------- ------------------------------ ---------- ---------- 3 NFACTORPDB READ WRITE NO SQL> select service_id, name, pdb from dba_Services; SERVICE_ID NAME PDB ---------- ---------------------------------------- ---------- 7 nfactorpdb NFACTORPDB SQL> Create
Read more

Wait for unread message on broadcast channel - Blocking Sessions

-
Image
What is Wait for unread message on broadcast channel wait event? Wait for unread message on broadcast channel is a wait event where source destination communication is involved and the database is waiting for a reply from remote party. Mostly this wait is seen related to data pump export (expdp) or import (impdp) operations. Although categorized in idle wait class "Wait for unread message on broadcast channel" can become the blocking session for some other sessions. Common causes for stuck sessions waiting on this wait event includes, Broken databases links, where remote database is not responding. Abnormally killed remote processes causing the sessions to wait. When a session is waiting on "Wait for unread message on broadcast channel" it can become a blocking session for dependent sessions. Most probably these sessions will be waiting on "library cache pin" or related concurrency wait events. The blocking_session column of (g)v$session view
Read more