[CentOS] clustered mail server?

Sat May 17 10:02:03 UTC 2008
Christopher Chan <christopher at ias.com.hk>

> Thank you for your input. I can't justify exchange (and don't want MS) 
> for 10 users. I do want IMAP though, and the calendar & address book 
> would be nice. This IMO has nothing todo with CentOS though, but at the 
> same time it shouldn't be limited to which Linux distro I'm using. As 
> you have said I may need to look at file system clustering instead, but 
> have never attempted it, so I don't know where to begin even. I know a 
> lot of MTA's can support a central user DB, but that won't sync the 
> emails. And this won't be a commercial installation either, it's for a 
> for a project in a rural community about 700km's from me, so it's more a 
> matter of if 1 server dies / crashes / packes up, and I can only get to 
> it 5 days later, the mail server still works :)

I don't know how cyrus does its clustering. You can check to see if it 
supports deliveries to all members of the cluster or whether it is only 
to a master.

No MTA out there cares about managing mail storage or making it 
available although some do provide pop/imap or both for a total 
solution. You can try dual deliveries. One to main box and another to 
the backup but there is simply no guarantee of the mail stores being 
kept in sync. If you can get GFS setup, that would be best but then that 
also involves a few boxes from what I understand...that is storage boxes 
and then combination smtp/imap boxes which will act as clients to the 
storage boxes. You could try installing opensolaris on the storage boxes 
such as the new Indiana release and use zfs to export the disk space as 
iscsi targets for GFS on the combination smtp/imap boxes. You could put 
smtp and imap on the same webserver/samba boxes too and put all your 
data on the opensolaris boxes...but I take it you already have those up 
and running.