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
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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
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Our customer asked if they can automatically upload latest RMAN backups via FTP to another server. Because they keep latest 3 backups in same directory, I wrote a small bash script which calls an SQL script to queries RMAN backups and then uploads only the backup pieces belong to the (more...)
When the 11.2.3.2.1 release of the Exadata Storage Server software was released, I was a little excited. There were numerous oneoff patches for the previous release, 11.2.3.2.0, which was the first version to support the Exadata X3, writeback flashcache, run UEK on the X#-2 systems, etc. With that many large changes introduced in one version, it was likely to see some bugs in the .0 release. Fortunately, Oracle was quick to fix many of those issues, but it resulted in several separate patches to update the cellsrv software.
I was working with (more...)
Recently, I’ve asked to help a client who was having doubts about their backup strategy. The client was considering image backup of database which would be constantly recovered and backed up to tape on the daily basis, by using “backup recovery area” command. However, there was a problem: there is no “restore recovery area” command. The utility to restore the recovery area seems to be missing, thus the name of this article became “The Case of Missing Utility”.
So, let’s see some definitions. This is what the client has envisioned:
RMAN> backup incremental level 1 for recover of copy database;
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Time for an update to a older post. I have previously talked about the annoyance of connecting to RMAN with a duplicated database where the DBID has not been changed. RMAN happily breaks the catalog by assuming the “new” database is a new incarnation, and prevents the previous owner of the catalog from using the backups.
I wrote a blog post a while ago about hacking your way past this problem, but was recently informed by Martin Bach that there was actually an RMAN command to fix the Incarnation problem I had encountered, so I though I had better take (more...)
I have announced my webinar on Oracle ZFS Storage Appliance for Exadata Backup & Recovery in NYOUG DBA webinar series. You can download webinar slides and voice recod from NYOUG web site
There are occasions when you recieve a complete backup of a database from a place different then yours and have to do a restore. normally a restore is simple . put the files in a directory run rman catalog on them and you are done. but what if you have rman
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My DBA friend Dejan from
Baze Podataka database related site wrote
post about Oracle Bug 8943287 which reminded me how dangerous bug this is. I was completely unaware about this bug till few months ago.
For this blog post I want to write about
“ORA-01578: ORACLE data block corrupted” error and recovery. It is easy to recover from such error if you have RMAN backup - you, of course, have RMAN backup? (if not, create one) Even if you don’t have RMAN backup you can perform block recovery from OS based backups (datafile copies).
But can you perform block recovery
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There comes a time when you need to find ways to get something done in an innovative manner with as little interruption to the primary as possible. This was the case that i was working on to rehost a database where i had network issues and a standby database available.
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These days I’m implementing Oracle Dataguard for two Oracle databases 10.2 as part of disaster recovery project, one of them is around 1.7TB, not yet production. As part of the DG setup backups have to be available for both primary and standby. I preferred to use ASM and was able to negotiate with the storage admin to run storage replication for the FRA disks during the backup. This way I would have the same structure and files, locally at the disaster site immediately after the backup of the primary database is completed.
Unfortunately two weeks passed and by (more...)
Two weeks ago a colleague DBA asked me what would be the best way to move SYSTEM tablespace with minimum downtime. There are several ways to perform that task and I will note what would be the best way in my opinion.
Messing with SYSTEM tablespace is always tricky so my goal would be
minimum risk and
minimum downtime.
My testing environment is 11gR1 database on Linux 32bit OS.
After quick search on that subject I’ve noticed that DBA’s are comfortable with moving/renaming other datafiles but SYSTEM or UNDO are making problems. Some tablespaces are essential and cannot be taken
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Original Post can be viewed at Using current_scn for RMAN incremental ? Think again..
I am bloging about experience we had using rman incremental backup for syncing standby database. We had a standby database which lagged by considerable time and we decided to use rman incremental database to make it current. We have done this in past and used normal procedure of taking current_scn from V$database on standby and took [...]
AskDba.org Weblog
This is a quick post regarding the error on the subject. This is the second time it happens to me, so I thought I will write a bit about it.
The problem:
I am refreshing one of my UAT environments (happens to be a Full Rack Exadata) using Oracle RMAN duplicate command. Then the following happens (on both occasions).
1.- Duplicate command fails (lack of space for restoring archivelogs, or any other error). This is can be fixed quite easy.
2.- following error while trying to open the database after restore and recover has finished:
SQL> alter database (more...)
I must say, this has been a busy weekend.
We have been promoting a release to production and a guaranteed restore point was created on Friday as rollback strategy. On Sunday I was called as we started to receive alerts.
The problem:
Our monitoring system started to send emails and SNMP Traps with the following alerts:
OEM alert for Automatic Storage Management +ASM4_ssssss4: Disk group RECO has used 100% of safely usable free space. (Current Disk Group Used % of Safely Usable value: 100)
OEM alert for Automatic Storage Management +ASM2_ssssss2: Disk group RECO has used 100% of safely usable (more...)
A datafile cannot be completely moved online in a user transparent way, but what it can be done is to minimize the time required to perform the operation, and avoid the traditional procedure executed when the database is mounted, which permits more availability for the non affected production tablespaces.
The operation can be performed by creating a datafile copy, either with the traditional commands or by means of recovery manager. In this case the following script was prepared to move a datafile.
run {
copy datafile ''
to '';
sql 'ALTER TABLESPACE OFFLINE IMMEDIATE';
set newname for datafile (more...)
This afternoon on a Oracle 11.2.0.2 installation, i was trying to run the Oracle RMAN utility. Rman cli was just hanging and not going into RMAN.
[oracle@linux2 ~]$ . oraenv
ORACLE_SID = [oracle] ? 11202
The Oracle base has been set to /opt/oracle/product/rhel4/database/11.2.0.2
[oracle@linux2 ~]$ rman
After entering above rman command, nothing happened. It just hung on the command prompt. I did not receive any error at all. Hmm… whats happening? I issued an CTRL-C to cancel it and tried again. Still same result. Okay lets trace it using Linux strace utility.
oracle@linux2 ~]$ strace rman
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Yesterday’s RMAN backup failed with ORA-19566 error reporting block corruption, here’s the error as reported by RMAN:
channel ORA_DISK_1: starting piece 1 at 20-JUN-11
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03009: failure of backup command on c1 channel at 20/06/2011 11:55:11
ORA-19566: exceeded limit of 0 corrupt blocks for file xxxxxxxxxx
The next logical step is to run DB Verify (dbv) utility to find out what blocks are corrupt. Dbv confirmed block corruption as shown below:
Corrupt block relative dba: 0x0346c3cf (file 113, block 229845)
Bad check value found during backing up datafile
Data in (more...)
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