On 10/14/2009 12:24 PM, Timo Sirainen wrote:
BTW. Have you tried maildir_very_dirty_syncs=yes setting? That should reduce disk i/o, and I'm really interested in hearing how much.
What are the downsides? Also, I'm guessing maybe there are certain conditions where you definitely don't want to do it?
The only reason you wouldn't want to set it is if cur/ directory is modified outside Dovecot. Or Dovecot is used without index files (or e.g. with NFS and local index files). The point being: Dovecot trusts index files to be up-to-date with cur/ directory's contents.
Although even then it still checks the cur/'s mtime to see if it had changed. The only problem is if Dovecot changes it at the same time as non-Dovecot. Then it doesn't know that there was a change. Unless the filesystem supports nano/microsecond mtimes, that'll make it very unlikely for Dovecot to miss this.
Perfect explanation, thanks. :)