Infrastructure at your Service
By William Sescu Relying to much on the RMAN Data Recovery Advisor is not always the best idea. In a lot of situations, it tells you the right things, however, sometimes it tells you not the optimal things, and sometimes, RMAN list failure does not show any failure at all, even if there is one. So … let’s simulate quickly a loss of a datafile during the normal runtime of the database. The result is…
By William Sescu Not to often, but sometimes you need to offload your RMAN backups and your DataPump exports to CIFS. You might run out of space on your NFS server, or you are a Windows shop who has only CIFS shares, and then you might need to put your RMAN backups to CIFS. One very important MOS Note regarding RMAN backups to CIFS is the following Is use of CIFS Protocol for RMAN backups…
By William Sescu I am planning to backup my 12R2 container database, because a huge application change is coming up, and I want to be sure that I have a good RMAN backup beforehand. For that particular DB, I want to do it with a cold backup in combination with RMAN tags. Unfortunately I don’t have any backups at the moment, so I start with a full backup with the TAG ‘DBI_BACKUP’ to be 100%…
By William Sescu From the RMAN point of view, you have generally two possibilities to store your backups, on Disk or on Tape. In case of a single instance, it doesn’t really matter from the accessible or inaccessible point of view. However, in a DataGuard environment it makes a huge difference. Per default, backups to Tape are always accessible and backups to disk always inaccessible. But what do you do in case you backup to…
By Franck Pachot . In a previous post I explained how to use transportable tablespace from a standby database. Here I’m showing an alternative where you can transport from a backup instead of a standby database. RMAN can do that since 10gR2.
By William Sescu The DBID is a very important part for Oracle databases. It is an internal, uniquely generated number that differentiates databases. Oracle creates this number automatically as soon as you create the database. During normal operation, it is quite easy to find your DBID. Whenever you start your RMAN session, it displays the DBID. [email protected]:/home/oracle/ [OCM121] rman target / Recovery Manager: Release 12.1.0.2.0 – Production on Mon Nov 28 10:32:47 2016 Copyright (c)…
By William Sescu Have you ever noticed a DB_UNKNOWN directory in your ASM structure? It usually happens in combination with spfile creation in ASM, or with RMAN spfile restores to ASM. The correct location is +DATA/<SID>/PARAMETERFILE/SPFILE.<#>.<#>, and an ASM alias from +DATA/<SID>/ pointing to it. But sometimes, the spfile ends up in +DATA/DB_UNKNOWN/PARAMETERFILE/SPFILE.<#>.<#> Technically no issue. The spfile in the DB_UNKNOWN directory is perfectly ok and can be used. However, you might need to adjust…
By William Sescu Do you see any differences between these two RMAN SHOW commands? RMAN> SHOW CONTROLFILE AUTOBACKUP FORMAT; RMAN configuration parameters for database with db_unique_name OCM121 are: CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO ‘%F’; # default and RMAN> SHOW CONTROLFILE AUTOBACKUP FORMAT; RMAN configuration parameters for database with db_unique_name OCM121 are: CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO ‘%F’; They are the same, except that the first output…
By William Sescu By default, automatic control file backups are disabled (even with 12c), maybe for performance reasons. RMAN> SHOW CONTROLFILE AUTOBACKUP; RMAN configuration parameters for database with db_unique_name OCM121 are: CONFIGURE CONTROLFILE AUTOBACKUP OFF; # default And also good to know, the autobackup after structural changes does not occur for databases in NOARCHIVELOG mode. So, if your database is running in NOARCHIVELOG mode, you will never see any impact, independent of controlfile autobackup is…
By William Sescu Not too often, but sometimes you might run into a situation when you lose everything, your DB Files, your Controlfiles and even your spfile. In situations like that, you need to restore first your spfile, then your controlfile and then the rest. For restoring the spfile, RMAN has a chicken/egg issue. To be able to restore the spfile, RMAN needs at least a running instance, but how do we start the instance…
