Yes - but how many users (on a typical ISP) will this support? My experience with NFS suggests that the number is less than 10000 accounts. In an early trial, reguardless of load, checking a POP account required 10-15seconds each. Normally, the same check is instantaneous on local drives. On the pop server, we normally have 5-10 simultaneous sessions on POP with about 200 per minute. On NFS, we could only process 100 connections per minute and the number of simultaneous connections jumps to 40+. After several minutes, the simultaneous conns started exscalating and the server crashes at 500. The same machine has no problem on local hard drive even during heavy spammings.
Duane. -----Original Message----- From: Gene Parks [mailto:[EMAIL PROTECTED]] Sent: Monday, March 11, 2002 3:01 PM To: [EMAIL PROTECTED] Subject: RE: high availability solution? If you had a common storage area i.e. a NAS then you could just bring the second server online mount the NFS and add the mx record. This would accomplish what you are looking for since when you take one out of service the other mail server trying to send mail will use the second record. And since the mail is local to all boxes then you do not have to worry about the mailhost attribute or clustering. -----Original Message----- From: manfred [mailto:[EMAIL PROTECTED]] Sent: Monday, March 11, 2002 6:52 AM To: [EMAIL PROTECTED] Subject: high availability solution? Hi everybody, I have a little understanding question to qmail-ldap. I haven't found an answer to this in the documentation yet, so I'll give it a try here. I'm running qmail-ldap without clustering enabled and it works really nice. Now I want to have a second server installed for the case, that the main server has to be maintained or is going down. As I understand (please help me if I'm wrong here which I certanly might), qmail-ldap has clustering support which is designed for load-balancing in the first place. So, when cluster-members receive pop3 sessions, they try to hand it over to the mailHost cluster-Server, right? But what, if this one is down? Does the session end with an error for the pop user? I assume, that smtp sessions (local delivery) will work and the cluster-member tries to connect to the mailHost cluster when it's up again to sync the maildirs, or am I wrong? So another way would be, to have a second MX entry, which would be fine for 'hot-standby' of the second server, but let's assume the case, that a lot of mails get handled locally in the time, the first server is down. Then, how is it possible to have the mails delivered from the second server to the first, so the maildirs of the first server have all the mails (because ongoing pop sessions will be handled by the first MX again)? I would really appreciate some hints on this topic, maybe a good starting point in the web for further research, befor I try to configure 'something'. Thanks a lot. Manfred
