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Re: Backup and bdb-logfile removal

Peter Mogensen wrote:

I've been going all documentation I can find (FAQ/bdb-docs..) and I
still have some doubt whether I understand this correctly.

All of your questions are answered in the official BDB docs.


These docs are for the current version, 4.6.21, but not much has changed in the description since 4.2.52.

I run frequent dumps with slapcat to backup the database, but I still
need to cleanup the BDB logfiles and it would also be nice get faster
back online after a crash than you can from LDIF.

So I understand how to create a hot backup by copying the database files
(db_archive -s) and then the log files (db_archive -l) and runing
db_recover -c.

No, "db_recover -c" is for recovering from a catastrophic failure. It's not for creating a backup.

I can see that I can delete unused log files (db_archive [no options])
from the backup. But when is it safe to remove log files from the active
db_archive on the active environment lists fewer files than on the
backup (predictable enough).

From the BDB doc page above:
To minimize the archival space needed for log files when doing a hot backup, run db_archive to identify those log files which are not in use. Log files which are not in use do not need to be included when creating a hot backup, and you can discard them or move them aside for use with previous backups (whichever is appropriate), before beginning the hot backup.

The docs say that running db_archive -d can make recovery impossible.
OK... so I don't do that.
But what is required of my hot backup snapshot to know that I can delete
log files from the active environment? (and which?) and still not
influence the posibility for recovery.

Could anyone list a step-by-step procedure to create a snapshot for
backup and prune the log files from the active environment?

The docs/ref/transapp/archival.html file that SleepyCat bundles in the BerkeleyDB installation provides all the steps.

btw: openldap 2.3.30/ bdb 4.2.52 (debian) ... but I guess that's not so
important here.

-- -- Howard Chu CTO, Symas Corp. http://www.symas.com Director, Highland Sun http://highlandsun.com/hyc/ Chief Architect, OpenLDAP http://www.openldap.org/project/