2 rman database repositries...

[B14speedfreak]

Hi all,

I am fairly new to oracle so please bear with me... my thanks in advance for reading and any posts.

I have been looking into what I have inherited, and seen that one of the big weak points that we have with our current backup situation is the rman database catalog.

Anyhow, I was reading the advanced rman notes from OTN's 10g libary, after being pointed that way by a different. Anyhow I read that you can register a database with 2 repositry catalogs. Unfortunately the advanced guid only has about 1/2 a page on it (1/4 of it is taken up by a diagram!) and no worked examples or syntax. Has anyone got any idea how you do it?

Thanks again for reading and for posts,




B14... aka... Marky Mark... the frozen monkey in the server room...

 

[LKBrwnDBA]

Yes, you can register the same database on two different catalogs by invoking rman something like:

rman TARGET / CATALOG rmancat1/rman@rman01
RMAN> REGISTER DATABASE;
RMAN> ...
rman TARGET / CATALOG rmancat2/rman@rman02
RMAN> REGISTER DATABASE;
RMAN> ...

Unfortunately when you do a backup using one catalog, the other will be out of sync.



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The person who says it can't be done should not interrupt the person doing it. -- Chinese proverb

 

[B14speedfreak]

Ok, but what if you issue a resync command manually, according to the documentation I can find this is suppost to update both catalogs...

thanks for the reply,

Mark

B14... aka... Marky Mark... the frozen monkey in the server room...

 

[LKBrwnDBA]

You would still have to 'add' the backup files from the first catalog to the other repository.



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The person who says it can't be done should not interrupt the person doing it. -- Chinese proverb

 

[B14speedfreak]

ok the backups we do get streamed straight to tape (strange I know but thats the way we do it) so why does the catalog have to have the backup files, I thought that the catalog just stored the file name / locations. Since we stream to tape a multi media manager is there. Doesn't this mean that RMAN would consult this catalog with the relevant file names???

Thanks for the posts though,



B14... aka... Marky Mark... the frozen monkey in the server room...

 

[LKBrwnDBA]

The catalog does not have the backup data, but the NAMES and location (metadata) about the backup files.

So, what I meant by 'add'ing is actually 'registering' (or cataloging) the backup file names from the first catalog to the other repository.


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The person who says it can't be done should not interrupt the person doing it. -- Chinese proverb

 

[B14speedfreak]

Hi,

Thanks for the posts,

Yes thats exactly how I understand that it works. But according to the limited documentation I can find on it, if you perform a "RESYNC CATALOG" its suppost to update the secondary catalog, is that incorrect?

We use backup scripts to perform our backups (like everyone else I imagine) and our thoughts where to run the "RESYNC CATALOG" command after the backup, thus in theory meaning that the second catalog should be up to date enough to mean that we could restore from the latest backup. Does that sound right?

Thanks again,




B14... aka... Marky Mark... the frozen monkey in the server room...

 

[LKBrwnDBA]

A RESYNC CATALOG only synchronizes metadata with the control file and updates all changed records for the physical schema: datafiles, tablespaces, redo threads, and online redo logs.

It will not register (add) metadata for missing backupfiles (those taken using another catalog).

PS: Even though you can register a database in two (or more) separate rman catalogs, you can only use one at a time when doing backup.

It is prefered:

1) Create rman catalog instance on separate server.
2) Backup catalog as any other production database.





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The person who says it can't be done should not interrupt the person doing it. -- Chinese proverb

 

[B14speedfreak]

Yeah you see we currently run 2 rman repositries (we have instances in the US and UK). However I was looking at complete system restore (if everything went), if we could register the instances with 2 repositires it would mean that potentially we could miss out a step on a total restore sinario (since we wouldn't need to the RMAN repostiry we could just the second).

We currently backup our rman databases via an export which although not idea does give us a lot of flexability ( we have also been able to do imports using the exports so it does work)....

I guess the only way you could keep the 2 repositries up to date would be to export one to another or something.

thanks for the post though, I will have a play...

B14... aka... Marky Mark... the frozen monkey in the server room...

 

[B14speedfreak]

Just been playing round with this idea.

I made a test database and 2 rman repositry databases on a single box.

Anyhow I did a full backup of the test database connecting with repositry 1, I then called a resync. I querried the first and second repositry for tags (select tag from RC_BACKUPPIECE. As per thought the first repositry had a backup with the tag, the second repositry did not.

I then did a backup of the test database using the second repositry, in the run command I used resync catalog before the release of the channel. Anyhow I then querried the tables again. The first repositry only had the first tag, the second however, had both the first and second tag...

...very very strange... I will have a mess about with it...



B14... aka... Marky Mark... the frozen monkey in the server room...

 

[B14speedfreak]

before I forget (this might might not be relevant) I am using a 10g database not 9i....

B14... aka... Marky Mark... the frozen monkey in the server room...

 

[B14speedfreak]

Hi All,

Been messing round with this. You can keep the meta data in the repositry in both catalogs up to date provided that after you have done your backup, you exit out of RMAN then reconnect, this time using the second repositry and issue a resync catalog - this does update the meta data.

I ran the following test:

shutdown the second repositry.

connect in rman to the target and first repositry

backed up the database

exited out

start up second repositry

connect in rman to the target and second repositry

resync catalog

shutdown the target and the first repositry

then deleted all control, log and datafiles in the target database

I could restore using the second repositry.

Prior to this there where no backups made of the database (as if it was a fesh install (no listed in either the control file or the other 2 rman repositries).

I was using ORACLE 10g R2, in archivelog mode, with the flash recovery area enabled.

I will see if it makes any difference without the flash recovery at some point.

Thanks,


B14... aka... Marky Mark... the frozen monkey in the server room...