On 281, 10 07, 2008 at 03:10:47PM +0300, Timo Sirainen wrote:
On Tue, 2008-10-07 at 11:38 +0400, Andrey Panin wrote:
On 279, 10 05, 2008 at 10:38:02PM +0300, Timo Sirainen wrote:
On Sun, 2008-10-05 at 21:28 +0200, Luuk wrote:
Last but not least, what gain will i have by using this plugin in combination with Maildir, or will it have more impact when mails are stored in mbox.
I guess it depends on the size of your mails. With mboxes it can be used only with read-only archives, so it's not all that useful. With maildir it can be used transparently with read-write mailboxes. I've no idea what the performance difference or space improvements are. I guess that'll also depend on your system.
I use zlib compressed maildirs on my primary server (12000+ users) and it achieves average compression ratio of 1.8, so if your system is io-bound you can spend some cpu cycles to significantly decrease disk load.
But is that 1.8 in bytes or disk blocks?
Bytes.
Or does it make much of a difference either way? Does 2x less space per message even matter with small messages since most disk I/O probably goes to seeking, so reading a single 4 kB message takes pretty much the same time as a 8 kB message?
Yes, for small messages it's not very usefull, but multimegabyte mails are quite common nowadays and for them compression is a clear win. Also I remember that load average decreased when I started to use message compression. I have no real numbers now, but it was noticeable.
-- Andrey Panin | Linux and UNIX system administrator pazke@donpac.ru | PGP key: wwwkeys.pgp.net