On Mon, 2013-07-29 at 11:48 +0200, Stéphane BERTHELOT wrote: > mdbox_rotate_size = 128M > mdbox_rotate_interval = 1d > mdbox_preallocate_space = yes > with virtual users and location like : > mail_location = mdbox:~/mdbox > > I don't think the remaining config is relevant but ask me if you need > some other parts. > > Using test accounts for 2 weeks now I've figured that the 128M > preallocated space is never 'hole punched" (to use a similar term than > "man fallocate" on Linux), even when rotating m.* files.
Yeah, those settings weren't really intended to be used together. > There would certainly be smart to use something similar to > "FALLOC_FL_PUNCH_HOLE" on rotation (when doing close() ?) so that when > we're sure there won't be anymore data appended to file that the > allocated space == used space. The problem is that there is no "rotation time". In normal operation Dovecot would be wasting time (=disk IO) looking at old files and figuring out if they would need hole punching. I guess the doveadm purge job could do that, but I'm not sure if that's always the best idea either. I remember some people using different mdbox settings for normal operations and for doveadm purge runs, so this could also unintentionally break things..
