On Tue, Mar 17, 2009 at 09:37:37AM -0400, Adam Tauno Williams wrote: > > > Not exactly sure what you mean here. I think you only need the database in > > > db.backup? and of course clean the environment before restoring such a db. > > AFAIK only that three databases are copied to the db.backupX directory. So if > > there are other checkpointed dbs they stay in the original place and I need to > > backup them? > > As I understand it: there is no reason to backup deliver.db, > statuscache.db, or tls_sessions.db. You can dump those without > consequence and they will be rebuilt on the fly. Yes - we delete these as part of our startup scripts (prefer not to have any BDB files lying around after a restart) Hey "checkpoint" is a massively overloaded term. In skiplist, a "checkpoint" is when the file gets rewritten in order. It's a complete rewrite of the file. Otherwise, skiplist is append only, so deleted or replaced records take up space. The algorithm for checkpoints is currently: tid->logend > (2 * db->logstart + SKIPLIST_MINREWRITE) Which basically means checkpoint when the file is over half garbage. I think that's actually a little too rare, especially with SKIPLIST_MINREWRITE = 16834, it means .seen files have a lot of junk in them! The "checkpoint" that ctl_cyrusdb does on the other hand, is totally different. It's just copying those files into the backup directories. It doesn't actually run a db checkpoint, at least not on skiplist. There's no way to trigger one externally. I have patches in the FastMail set that tune SKIPLIST_MINREWRITE lower, and the amount of junk required lower. They also do a checkpoint every time we run recovery (recovery is basically going through and recreating all the links between records, rolling back any uncompleted transaction as well). I think the "checkpoint on recovery" code will go into 2.3.15 - it makes sense to rewrite the file when it's hot. Bron. ---- Cyrus Home Page: http://cyrusimap.web.cmu.edu/ Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
