Restore a database from datafiles and logfiles

[Former Member]

We are trying to restore a old ( last week ) copy of our database in

order to retrieve the contents of one table from a specific day.

We have recovered copies of the datafiles and logfiles and need to

bring them online ( if possible ).

Unfortunately we cannot use our standard backup/recovery system because

its utilizes snapshots & and images at the SAN level which is built

around failing over to a disaster site.

I am searching the web ( OSS, SDN & the web in general ) looking for an

answer .

Do you know if its possible and ifso how do we do it with maxdb

v7.6.6.09 ?

Thanks in advance

Gary Vaughan

[Former Member]

Hi,

Got it working by doing the following

basically initialized the target db with the same data file charateristics as the source, recopied the data files , bought it into admin mode, backuped it up and restored it with initialisation, reloaded the system tables, changed the sid and I was able to extract the table we required.

Thanks everyone for your help

Gary Vaughan

[Former Member]

Hi,

Thanks for your answers, my apologies for not having the terminology correct. The answers are basically what we thought.

Also the backup process works extremely well - my problem is that we need to get the contents of a table at a point in time, while leaving the current production environment online. Recovering the production database is not the issue.

Thanks again

Gary Vaughan

[lbreddemann]

> Thanks for your answers, my apologies for not having the terminology correct. The answers are basically what we thought.

>

> Also the backup process works extremely well - my problem is that we need to get the contents of a table at a point in time, while leaving the current production environment online. Recovering the production database is not the issue.

Hmm... ok, so when you've got the database online again, then it's pretty much straight forward to export a single table.

However, whenever you take out a single part of the database from a certain point in time and put it in back to the database at a later point in time, you have to make sure that the application data is logically consistent yourself!

The database cannot do this for you.

The pure technical part for that can be accomplished e.g. with the LOADERCLI (see tutorials for the loader in the documentation!) or via the transport feature of DB Studio.

regards,

Lars

[lbreddemann]

> We are trying to restore a old ( last week ) copy of our database in

> order to retrieve the contents of one table from a specific day.

>

> We have recovered copies of the datafiles and logfiles and need to

> bring them online ( if possible ).

No, you haven't recovered anything yet.

What you did was to put the files back to the filesystem location from where they had been copied.

That's called "restore".

"Recovery" is about making the database transaction wise consistent again.

It's all about transactions - not about files.

In MaxDB data volumes aren't online or offline - they are either available to the database or not.

> Unfortunately we cannot use our standard backup/recovery system because

> its utilizes snapshots & and images at the SAN level which is built

> around failing over to a disaster site.

Wow - once again somebody who designed a backup strategy on the whiteboard without considering the single most important part: how to get the database working again.

> Do you know if its possible and ifso how do we do it with maxdb

> v7.6.6.09 ?

Technically it is possible to re-create a database instance just with having I/O consistent copied of the files.

But there are lot's of constraints that have to be met (database parameters have to match, files need to be located at the same location, the number of files must match the configuration when the files where copied, etc.).

The link you already got in the other reply is a good starting point.

Try out the method described in the Wiki and let us know whether you run into any problems.

Make sure to check the KNLDIAG file for error messages.

regards,

Lars

[Former Member]

Hi Gary,

did you check the wiki?

http://wiki.sdn.sap.com/wiki/display/MaxDB/HowTo-CreatingacloneofaSAPMaxDB+database

part "Creating a clone manually via reusing volumes and parameters"

Best regards

Christian