Tuesday, November 08, 2005

Dialtone restores,the Recovery Storage Group, and swapping out database files

In my Analysis of Disaster Recovery session as well as a couple of other sessions, there were a lot of good questions on using the Recovery Storage Group. Someone asked if you can do a dial-tone restore, then restore the production database to an RSG, then swap out the RSG database with the "dial-tone" database, and then finally ExMerge the data from the dial-tone database in to the production database.

This is a good idea to do, since the dial-tone database will not have a lot of the mailbox "meta-data", such as mailbox/folder rights, rules, forms, etc... This data will be in the RSG database, though. So swapping them out once the RSG database is restored from tape, is a good idea.

I had not done this, but it is possible. I found some good reference material in the Microsoft whitepaper "Using Exchange Server 2003 Recovery Storage Groups", including steps on how to swap out the RSG with the dial-tone database. Essentially, here are the steps necessary if you lose the production database and want to do a dial-tone restore:
  1. Delete the production database files and remount the store. Answer "yes" when Exchange System Manager asks if you want to creatre new database files
  2. At this point, users can go back to work, albeit with empty mailboxes.
  3. Create a Recovery Storage Group and create the mailbox store in the RSG that you wish to restore.
  4. Restore the last backup of the production database to the RSG
  5. Make a backup copy of the production database that was created from the dial-tone restore
  6. Dismount both the production database and RSG database. Copy the RSG files in to the production database location. Copy the production database files in to the RSG location.
  7. Rename the production database (now in the RSG folder) to the name of the RSG database. Rename the RSG database (now in the production database folder) to the name of the RSG database.
  8. On the database properties, click the checkbox that allows the database to be restored from backup.
  9. Mount both databases.
  10. Merge the data in the RSG database (the dialtone data) in with the production database.

While this is just an overview, it gives you an idea of what the steps are. I recommend you read the Using Exchange Server 2003 Recovery Storage Groups whitepaper and practice this before you have to do it in production.

5 Comments:

At 10:33 AM, Blogger Wolfgang said...

Hi Jim,
if you restore the database from the last full backup you will loose the items since then. It is possible to roll forward the transaction logs of the production storage group into the recovered database in the recovery storage group. Just copy all transaction logfiles (incl. Exx.log) to the recovery storage group transaction log directory and start the rollforward with eseutil /cc.

Regards
Wolfgang

 
At 8:22 PM, Blogger Jim McBee said...

That is a good question. I thought of that myself and asked a couple of people. Based on what I found out, it is not possible to roll the transactions from the production database forward in to the RSG database. I'm pretty sure the reason is that the database signature would not agree with the signature the log files expect.

 
At 9:40 PM, Blogger Wolfgang said...

I've done that several times, it works.

 
At 5:46 PM, Blogger Todd said...

Jim:

From a client perspective...outlook 2003 will ask to connect online or work offline. If you choose offline then you have all your old e-mail from the .ost but will be unable to send and receive messages. If you connect online you will be able to send and receive new messages but will not have your original messages.

 
At 10:28 AM, Blogger Nawar75 said...

5- Make a backup copy of the production database that was created from the dial-tone restore

u mean the one newly created that have the new mails while restore to RSG being done ?

 

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