On 12.12.2010, at 9.39, Stan Hoeppner wrote: > mail_location = maildir:~/Maildir:INDEX=MEMORY > > The ":INDEX=MEMORY" disables writing the index files to disk, and as the > name implies, I believe, simply keeps indexes in memory.
I think maybe I shoudn't have called it INDEX=MEMORY, but rather more like INDEX=DISABLE. > "If you really want to, you can also disable the index files completely > by appending :INDEX=MEMORY." > > My read of that is that indexing isn't disabled completely, merely > storing the indexes to disk is disables. The indexes are still built > and maintained in memory. > > Timo, is that correct? It's a per-connection in-memory index. Also there is no kind of caching of anything (dovecot.index.cache file, which is where most of Dovecot performance usually comes from). > I don't know if, or how much, storing them in RAM via :INDEX=MEMORY > consumes, as compared to using a ramdisk. The memory consumption may be > less or it may be more. Timo should be able to answer this, and give a > recommendation as to whether this is even a sane thing to do. I think INDEX=MEMORY performance is going to suck. http://imapwiki.org/Benchmarking explains IMAP performance a bit more. By default Dovecot is the "Dynamically caching server", but with INDEX=MEMORY it becomes "Non-caching server".