I’m about to deploy transactional logging for our mail server (approx. 150 users w/ 400 meg quotas) and one 8 gig database. I’m debating between circular vs. archive styles in an environment with about 20 gigs free. For those that have done this:
If you chose circular (with 4 gigs), how far back did your entries go?
If you chose archive, can you describe your environment? (i.e., space used between archives, databases included, days back for restores, satisfaction with the method?)
Also, if the method we chose turns out to be inadequate, can you switch to the other without much grief?
Subject: Transactional loggers: Circular vs. Archive
If you are going to use it in conjunction with archive, use archive, if not, use circular. The only benefit of circular is your server restarts faster. It may not be used for archiving purposes. Circular will simply reuse the extent files defined in the log file size you define (ie: 4gb).
To switch, it’s best to disable transaction logging, remove the log files, then re-enable as the other.
The logs would not be re-useable once removed. But why would you need, for example, the circular logs when the changes have already been committed to disk? What would be the benefit of keeping them? You can’t do anything with the circular anyway.
In regards to the archive, you could keep those and use them during your restore of databases.
Subject: Transactional loggers: Circular vs. Archive
The main factor here to consider is whether you are going to be using approved backup software for Lotus Domino, or not.
Archival style TL REQUIRES this approved backup software. Part of the function of the backup is to mark the transaction log extants (files) such that Domino knows that it can write over them when it needs to create a new TL extant.
Circular style TL, on the other hand, does not require this specialized software. As you noted, the TL is limited to 4GB.
Starting in Domino 7 is the option to use linear style TL. according to the Admin help, Linear is the same as circular, but allows more than 4GB.
Our need is mainly for recovery, so circular fit the bill better. We may look at archival later, but for now, this works.
How much data will be stored in the logs depends on how much activity there is on the server. With your workload, I suspect that you’ll get a few days at least.
One way to get an estimate is to use mail journalling. If you journal everything, look at how big your journals are and that should tell you how far back your logs will go. If you have 3 days of journals that equal 4GB, then that’s about how much your logs will hold. ← Got this from someone at IBM Support