I love to read Oracle related blogs, forum posts and mailing lists much more often than books. Why? Because there many Oracle DBA’s and developers share their experiences, problems, "best practices",... which are very valuable to me.
It's great that we have so big and active Oracle community.
Today I noticed mail from Oracle-L
list where someone asked for help with recovery after overwriting production controlfiles. Check Oracle-L
for more info.
It reminded me that (more...)
Normally, when I create physical standby database, the configuration has the same directory structures and name values as production with the exception of db_unique_name.
But this time was not the case as shown below.
ANGEL:(SYS@xmenstby):PHYSICAL STANDBY> show parameter name
NAME TYPE VALUE
------------------------- ----------- ----------------------------------------
db_file_name_convert string /oradata/xmenprod, /oradata/xmenstby
db_name string xmenprod
db_unique_name string angel_xmenstby
global_names boolean FALSE
instance_name string xmenstby
log_file_name_convert string /oradata/xmenprod, /oradata/xmenstby
service_names string xmenstby
For almost five years, I have used RMAN very minimally.
Luckily, learning RMAN is like learning to ride a bike. One may not be able to perform wheelie, but one does not forget.
Please allow me to share the details on how to restore database to a new server, new database name, and new location using RMAN.
At source, database is using OMF and backup is located at /oradata/backup.
At target, database is not using (more...)
You have lost the controlfile
, the catalog
and the backup to the controlfile
too; so restoring the controlfile from a previous backup is not an option. How can you recover the database? By creating the controlfile from scratch. Interested in learning how? Read on.
Here is a final thread to the blog posts I had posted in the last three days, about interesting situations faced by John the DBA at Acme Bank. In the (more...)
You lost your controlfile and the catalog. To restore the controlfile, you must know the DBID. Did you follow the advise to write down the DBID in a safe place? You didn't, did you? Well, what do you do next? Don't worry; you can still get the DBID from the header of the data files. Read on to learn how.
If you have lost your controlfile and the catalog database (or the database was not (more...)
Allow me to present the snapshot of a day from the life of John--the DBA at Acme Bank. On this particular day a database John manages crashed entirely and had to be restored from the backup. He takes regular (backupset) RMAN backups to tape. Since everything--including the controlfile--had crashed, John had to first restore the controlfile and then restore the database. The controlfile is always backed up with the backup database command. John was sure (more...)
This week I migrated our EM12c repository database to a new server as part of it's promotion to production status. Just to make it a little more exciting, the migration also involved an in-flight upgrade from 184.108.40.206 to 220.127.116.11. Much of this post is directly inspired by Martin Bach's post on the same subject
. I ran into a few other snags that weren't mentioned so I thought it would (more...)
Last Friday I kicked off a database backup to an NFS destination, using the standard "backup as compressed backupset database" syntax. Loyal readers of this blog may recall that I'm the proud custodian of a 25 Tb database, so this backup normally takes a few days, with an expected completion on Monday morning. However it was still running on Wednesday, and reviewing the logs I saw that there was just 1 channel (of the original (more...)
I've recorded backups on tape to RMAN repository several times already, but every next time I needed to do that I was searching through notes to find proper procedure.
This time I will note procedure in form of the blog post.
Test is performed on Oracle version 18.104.22.168.
These were my unsuccessful attempts:
3> allocate channel c1 device type 'sbt_tape';
4> send 'NSR_ENV=(NSR_SERVER=backup_server,NSR_CLIENT=oracle_client,NSR_DATA_VOLUME=OrclPool)';
5> catalog backuppiece 'ARCH_ORCL_rep2dod5_s128878_p1';
When I sat down at my desk yesterday morning I was greeted with some disturbing email alerts notifying me that one of the NFS mounts on my standby database host was full. This was the NFS mount that held an image copy of my database that is updated daily from an incremental backup. The concept and an example can be found in the documentation
. With a 25Tb database, waiting to restore from backups is not (more...)
I was recently configuring backup on the customers Exadata with IBM TSM Data Protection for Oracle and run into weird RMAN error. The configuration was Oracle Database 11.2, TSM client version 6.1 and TSM Server version 5.5 and this was the error:
[oracle@oraexa01 ~]$ rman target /
Recovery Manager: Release 22.214.171.124.0 - Production on Wed Jan 29 16:41:54 2014
Copyright (c) 1982, 2011, Oracle and/or its affiliates. (more...)
We want restore backup from source. So we took backup from source and copied it to /dba/share/MYDB on target. My collouge sent me email saying restore failed with following error
rman target /
Recovery Manager: Release 126.96.36.199.0 - Production on Wed Sep 18 20:47:38 2013
In this post I want to explain how to create duplicate database from active 11gR2 database using RMAN. There are many blog posts covering that subject but most of them are covering non-ASM to non-ASM, ASM to ASM or non-ASM to ASM duplications.
I want to cover ASM to non-ASM (more...)
I am regular follower of Oracle-l
mailing list which is great source of knowledge for Oracle experts. Two days ago one Oracle DBA posted question “RMAN restore/recover problem
” which induced me to re-check my knowledge about some RMAN PITR scenarios.
So I’ve performed some tests and decided to (more...)
Starting with 11g Oracle can perform block media recovery using flashback logs to get good copies of the blocks.
Flashback database is not enabled by default so first step would be to enable it. When enabled a process RVWR (Recovery Writer) copies modified blocks to flashback buffer. Later this buffer (more...)
In this post I will describe how to change Oracle SID using utility DBNEWID. As I can see DBNEWID is available from 9i version but I’ve never heard about it. Till now, I have used procedure where I’m manually editing and re-creating control file.
But I think it’s much better (more...)