RMAN backups

[chikkodi]

Hi,

I am working on setting up a backup schedule for our database. We plan to use RMAN and I am looking at incremental backups.

So, from what I have read so far, we have level 0, 1, 2 and so on. Level 1 backup will backup all changed blocks <= other level 1 backups.

So, if we schedule say for example, level 0 backup every Sunday, and level 1 backup every other day of the week, and our database was fine for 1 year and then we needed to recover, would we need ALL the level 0 backups from the past whole year and then the level 1 backups for that week when the database went down ?

[abhijit]

You need the latest one and the incremental backups that are taken after that full backup.

abhijit

[sambavan]

You would only require the last Level 0 backup and all the Level 1 backups. On the other hand if you have done a cumulative backup, then you would require the level 0 and the last cumulative of level 1.

Refer: http://www.oradoc.com/ora816/server....rt1.htm#435958

Sam

[sambavan]

Originally posted by abhijit
You need the latest one and the incremental backups that are taken after that full backup.

abhijit

Remember Full backup is different from the Level 0 backup. Never confuse this, and one will not go with the other.

[chikkodi]

Thanks for your responses.

If you look at the following URL

http://www.oradoc.com/ora816/server....onc.htm#436081

and search for "Figure 1-14 Differential Incremental Backups (Default)"

It shows a backup schedule. In there it says that the 0 level backup taken
on the third Sunday, only backs up till the second sunday and not the first
sunday.

Could you please clarify this for me ?

Thanks again.

[sambavan]

But if you read the explanation it states what happens:

An incremental level 0 backup backs up all blocks that have ever been in use in this database.


Sam

[chikkodi]

Thanks so much for looking into this. That eases a lot of my concerns, otherwise it will be a nightmare to keep ALL level 0 backups at hand. I guess I was kind of confused when the figure showed something different. Also the definition says "level n backup backs up everything <= n", hence I assumed that level 0 would backup only till the last level 0. But that would be crazy. Hence I think you are right.

Thanks!

[sambavan]

That is a general point of confusion for every one.

Sam