On Sat, 11 Aug 2001, Russell Coker wrote:
On Sun, 5 Aug 2001 16:10, Przemyslaw Wegrzyn wrote:
I'm looking for good solution for big, scalabale mailserver installation,
for 500,000 accounts and more...
As for now I think:
- sharng NFS-mounted mail storage is not so good idea.
Why not? If you use Maildir storage then it's NFS safe. If you use a NetAPP
Filer, a VA NAS device (or any machine running 2.2.x kernel with LVM, Ext3,
and appropriate NFS kernel-server patches as the VA NAS devices did), or some
similarly powerful NFS server then performance should be more than adequate.
Hmmm, I'm really afraid about NFS, I've heared that Linux NFS
implementation is broken, many times. Can anyone explain it a bit ?
For Ext3 you need to keep the number of entries in a directory down to 1000
for best performance, but most users don't have that many messages in their
mail folder. So you just have to do suitable directory hashing to make sure
you don't have too many users in a directory (all mail storage software has
support for this).
Yeah, I do such hushing on every bigger mailserver, it's a common
solution.
Currently I'm testing qmail-ldap + maildrop + Courier-IMAP.
Works well, but it's not HA solution :|
Then you can have multiple mail servers running at the same time for
increased reliability. This is much better than the Perdition approach of
increasing the number of points of failure. Having an NFS file server as a
single point of failure is as good as it gets, making an NFS file server
reliable is much easier than making a mail server reliable...
Running multiple mail servers over NFS will actually makie it HA-like
system. But is it good solution for high load ?
Using perdition-like solution to split mailspool between separate NFS
servers, and using multiple mailservers for each NFS backend would
probably build good scalable solution.
-=Czaj-nick=-
--
To UNSUBSCRIBE, email to [EMAIL PROTECTED]
with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
