Cross-endian Oracle migration – moving user data – part II

In my previous post I shared some findings on migrating user and application data between platforms with different endianness, focusing on problems with reducing downtime.

Today I’ll talk more about the complexity of chosen method. It’s not only about complexity per se, it’s rather about the possibility to automate as much as possible in order to allow efficient migration of a big number of databases.

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Cross-endian Oracle migration – moving user data – part I

One can find a lot of sources and materials regarding migrating Oracle databases between platforms having different endianness, even though the choice of possible methods is limited in this case. On paper (slides?) everything looks fine, but then you hit bugs or environment-specific problems. Moreover, in real life the situation is always more complex than moving just one tablespace with just one datafile as shown in many places as an example. Today I would like to add my 2 cents into this topic, focusing on moving user and application data.

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Monitor backup jobs using RMAN views

Proper monitoring of backup jobs is one of the crucial elements in ensuring that your databases are well-enough protected against data loss. You can for example grep your backup logs, put some kind of alerting inside your backup scripts, but the most obvious method is just to use Oracle dictionary views.

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Oracle 12c – causing problem by solving it!?!

Originally posted on “Databases at CERN” blog

Regular readers of our blog probably already know that for most of our databases we’re using two storage layers to keep our backups – NAS volumes as a primary layer and tapes as secondary one – please check Datafile without backups – how to restore? for more details.

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Potential of “import catalog” command

Originally posted on “Databases at CERN” blog

Since version 11.1 of Oracle database, there is very useful command available, allowing DBAs to easily move RMAN recovery catalog schemas between databases. Its functionality is even broader, as it also allows one catalog schema to be merged into another – either the whole schema or just the metadata of chosen databases. Command I’m writing about is of course IMPORT CATALOG, which I had a chance to use recently, to move our recovery catalog to the new database. It was moved from Oracle 11.2.0.3 database to 11.2.0.4, with recovery catalog schema using below version:

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Datafile without backups – how to restore?

Originally posted on “Databases at CERN” blog

Have you ever had a problem with restoring datafiles without any backups available? It’s easy, of course if you have all archived logs from the time datafile was created. Please check it here: Re-Creating Data Files When Backups Are Unavailable. Moreover, RMAN is clever enough to create empty datafile automatically during restore phase and then recover it using archived logs. So far, so good, but…

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Importance of testing yours backup strategy

Originally posted on “Databases at CERN” blog

Most of you for sure know, that ability to restore data in case of failure is a primary skill for each DBA. You should always be able to restore and recover data you’re responsible for. This is an axiom. To be sure, that you’re able to do it, you should test it on regular basis. There is of course possibility to use some Oracle features, like BACKUP ... VALIDATE or RESTORE ... VALIDATE commands, but if you want to be certain as much as possible, the only way is just to run real restore and recovery. Doing it periodically for big amount of databases is extremely tough, both because of resources needed and DBA time. That’s why one of our DBAs Ruben Gaspar Aparicio has created recovery system, which is heavily used at CERN. Good news – it is available as Open Source on Sourceforge (Recovery Platform). Since its release we’ve introduced many modifications to it, but still it could be good starting point to check the source code in order to start developing your own solution. We’re using it as a validation of our backup strategy, to run real restore and recovery every week or two for most of our databases.

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