RE: [courier-users] Disaster tolerant IMAP and SMTP ?

[Mitch \(WebCob\)]

Yes it's ok to have to couriers writing to one files system - yes - rsync is a good option to mirror things. Courier users are not nessecarily HA users, and it's not an application issue - its an implementation issue for structured HA systems where courier forms a component.     m/ -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]On Behalf Of Lars Holmstr�m Sent: July 12, 2003 12:11 PM To: [EMAIL PROTECTED] Subject: Re: [courier-users] Disaster tolerant IMAP and SMTP ? One of my options would be to provide a NFS mountpoint that I ca provide via another cluster file system.    Is it ok to have two courier boxes writing in to the same NFS mounted disk ?   If I undertsand the Linux world correct the clustered file system is the key to build bullet proof solutions. Or is there a way to have two courier boxes replicating each other, via rsync for example ? I do know this is probably off topic, but still, having to deal with courier as an application, how does people solve the problem ?   /Lars  ----- Original Message ----- From: Mitch (WebCob) To: Lars Holmstr�m ; [EMAIL PROTECTED] Sent: Saturday, July 12, 2003 9:04 PM Subject: RE: [courier-users] Disaster tolerant IMAP and SMTP ? You've got a few things to look into Lars - this isn't really a courier question...   You need to look at distributed replicated storage systems (afs, coda, or simply replicated NFS...) which are all off topic....   Then you need to decide your method for connection failover - DNS with recrd updates when a node fails is probably your best bet if you are operating on different networks... you can expect your data transfer volume to be doubled though - as ever file that is created or moved on one system has to be transfered to the other system...   m/ -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]On Behalf Of Lars Holmstr�m Sent: July 12, 2003 10:10 AM To: [EMAIL PROTECTED] Subject: Re: [courier-users] Disaster tolerant IMAP and SMTP ? The question is about how to create a distributed imap-server with a multiple site storage. /Lars ----- Original Message ----- From: James A Baker To: [EMAIL PROTECTED] Sent: Saturday, July 12, 2003 5:51 PM Subject: Re: [courier-users] Disaster tolerant IMAP and SMTP ? On Saturday, Jul 12, 2003, at 07:27 US/Central, Lars Holmstr�m wrote: I consider building a disaster tolerant mailsystem for in and outgoing mail.   I already have two ISPs and MX records that direct incoming mailtraffic properly.   The problem seems to be the IMAP.   Does any one have a suggestion for how to do this ?   /Lars Ps. Disaster tolerant in my view is when I can afford to loose one computerroom completely and the service from a users perspective is still available. Ds. Is your question about how to initially create a redundant IMAP data store across your server rooms? Or how (after it's all created) to let users reach it automatically, regardless of which computer room is still alive after a failure? I.e. Server implementation vs. DNS implementation? (...or both?) -jab