Tom,

        When running in 'roll-forward recovery' mode, the recovery log tracks
all transactions since the last database backup - this significantly
increases the recovery log storage requirements.  Database growth will
certainly contribute to this but keep in mind that database transactions
also incrlude client backups/archives and 'background' processing such
as migrations, reclamations, expiration processing, etc.. What you're
seeing in your environment isn't out of line with what I saw when
running in roll forward mode - our database was about 7 GB and I had to
increase our recovery log from 600 MB to about 3 GB (dbbackuptrigger set
to 80%)  to avoid database backups being triggered while the incremental
backups were running.  Since migrating to an RS/6000 and fast tape
drives, I've given up on this method and have gone to full database
backups every day since they only take 45-50 minutes.

Tim Pittson
tpittson AT himail.hcc DOT com

>----------
>From:  Thomas A. La Porte[SMTP:tlaporte AT ANIM.DREAMWORKS DOT COM]
>Sent:  Wednesday, March 05, 1997 12:12 PM
>To:    ADSM-L AT VM.MARIST DOT EDU
>Subject:       Recovery log
>
>I'm curious to know what fills up in the recovery log between
>database backups. My recovery log is currently 888MB, with a 16GB
>database that is currently 60% full (roughly 8.5GB). In spite of
>what I consider a fairly large recovery log (approximately 10% of
>the current DB size), I can't seem to make it through 24 hours
>without triggering a database backup.
>
>We have a regularly scheduled database backup around 3:30pm, yet
>I continue to see a database backup triggered during the nightly
>backups. My database has never grown more than 150MB in a single
>night, so why is my recovery log filling to capacity? (The
>current dbbackuptrigger is set to 80%.) I would *really* like to
>avoid these extra triggered backups, but I can't continue to
>throw disk space at the recovery log. I had to give up mirroring
>(which cost me last week when I lost one of my recovery log
>volumes) to increase the size of the log.
>
>Is there something accumulating in the recovery log that I can
>prune, or that I do not need to retain, that might keep the usage
>to a more reasonable volume?
>
>Current platform is AIX 4.1.4, server is 2.1.8. Running on a
>SP2 wide node. Any suggestions or comments appreciated.
>
>Thanks. -- Tom
>
>"If I could dot the 'i' in a Michigan     Thomas A. La Porte
> game and the good lord came to take me   Archivist, Feature Animation
> the next day ... at least I could        DreamWorks SKG
> die happy." - Beano Cook, ESPN           <tlaporte AT anim.dreamworks DOT com>
>