On Fri, Jan 19, 2001 at 10:14:09AM -0600, Bill Carlson wrote:
> On Fri, 19 Jan 2001, Henning Brauer wrote:
> > On Thu, Jan 18, 2001 at 07:35:33PM -0500, [EMAIL PROTECTED] wrote:
> > > My question is, is it possible to run multiple instances
> > > of qmail, sharing the same disk structure, configuration, etc..
> > at least /var/qmail/queue/ must be local. Maildirs on NFS isn't that problem.
> > I won't rely on linux NFS, but thats another thing.
> And the queue is a point of failure, if the filesystem with the queue dies
> with mail in the queue, said mail is gone. Which means if you really want
> HA, the queue should sit on a RAID1 or similar. RAID5 would be a nasty
> performance hit.
I took this a precedence, of course.
> > > That's plan A. Plan B is setting up a dedicated mail
> > > server, which I would like to avoid if necessary,
> > > because it won't scale nearly as well.
> > For first: for performance reasons one qmail machine _might_ be enough.
> > You also might want to look at qmail-ldap with its native clustering
> > support. http://www.nrg4u.com, docs at http://www.lifewithqmail.org/ldap/
> > You should also spend some thoughts on your OS, the *BSDs may be much better
> > choices for a high volume qmail server.
> qmail-ldap looks great, LDAP lets you distribute your authorization
> information and supports HA similar to the way DNS works. However,
> qmail-ldap's definition of clustering does NOT include HA or failover,
> last I heard. It does handle distributing mail delivery across a cluster
> of machines in a transparent manner.
You are right. qmail-ldap's clustering is just one important piece of you HA
solution. Use some kind of IP based HA solution (like BigIP) for the MXes
and the user intercating machines (outgoing SMTP, pop/imap), and build a hot
standby solution for your Maildir holding machine. An external RAID with at
least two external SCSI busses is a must here.
> $.02
>
> Bill Carlson
> --
> Systems Programmer [EMAIL PROTECTED] | Opinions are mine,
> Virtual Hospital http://www.vh.org/ | not my employer's.
> University of Iowa Hospitals and Clinics |
>
>
--
Henning Brauer | BS Web Services
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[EMAIL PROTECTED] | 20459 Hamburg
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