DR and failback

[ilpadrino]

I'm obviously not yet an expert with Exch2K3. But isn't it true that the logs mean everything to exchange server - that messages are delivered to mailboxes based on those incoming logs. What happens with the logs once the email has been processed to the recipient's mailbox? How would I go about saving those logs in order to replay them for failback purposes?

Thanks in advance.
Joe

 

[nickpark]

The Transaction Logs record all changes made to the mailbox databases. Therefore, if your database dies, you can reapply all the transaction logs from the last full database backup to restore it to the up to date state.

I think you need to read about backups/restores...... I hope you have a few days spare!
Exchange Technical Documentation Library

http://www.microsoft.com/technet/prodtechnol/exchange/2003/library/default.mspx

 

[ilpadrino]

Most of the documents in the DR section of the link you attached are about cluster service, which I do not have.

As you stated: If logs have been running on a failover computer, theoretically when the primary comes back online, I can take the logs from the failover and replay them to bring the primary up to date. So back to what I was trying to ask. Are the logs, or information within the logs deleted after being processed? If not, then I can take the same logs from the failover server and copy them to the restored primary, then run through eseutil, etc.

 

[nickpark]

I think what you may be referring to is a dial-tone scenario... I don't know about this but it goes something like this...

Primary server fails. All users booted out of Outlook.
All mailbox changes are lost from the last backup (forever).

Start up standby server and create empty (dial-tone) mailboxes for the users, redirect them to this server. They can now login and start emailing again - but they have none of their old emails.

At this point, you are in the process of restoring the last full Storage Group backup.

When the restore is complete, you can mount the restored mail stores onto the recovery storage group. From here, you can move the restored mailbox content into the dial-tone mailboxes - while the users are still online.

Then you can think about moving back to primary server.

(Transaction Logs are only deleted after a full or incremental backup has successfully run, but this isnt really related to dial-tone restores.)

If I'm completely off here, you need to post exact scenario of backup details, failover scenario, exchange infrastructure/org /server structure and shared (or not) storage setup.

 

[mtnathan]

If you have a simple One exchange server and if you are worried about the transaction logs. Then this is how it goes.

There are two sets of files - databases / transaction logs (and also the checkpoint of course) .

Databases are the files where the mails are committed to stay for eternity. There are two types of database files, edb and stm and they go together. If you look at the exchange system Manager and drill down and check the properties of your store - database- you will see edb and stm.

Transaction logs are the files which act as intermediaries.
In exchange 2000 / 2003 (depending on the edition of exchange you have i.e. standard or enterprise) you can create multiple stores under a storage group. The storage group is the one "owning" the transaction logs.

You can enable or disable circular loggin at the storage group level.

IF you do full backups and if you are not doing circular logging the logs will get truncated. Logic is that from that point onwards you want only the newer transactions. Anything old is already in the tape (either as EDB/STM or Transaction logs).
IF you do incremental backups again the same thing happens.

For DIff/copy backups the logs wont get truncated.

http://www.microsoft.com/technet/pr...ide/516ca17d-5452-41eb-a2d9-dc95f16405a4.mspx

In this page, dont get confused by the initial section where it talks about offline backups. Scroll down and go to the area at about FIg 2.4 and start reading.