7 messages in net.sourceforge.lists.courier-usersRe: [courier-users] Redundant IMAP se...
FromSent OnAttachments
robinNov 18, 2001 8:08 pm 
Les StottNov 18, 2001 8:40 pm 
Sam VarshavchikNov 18, 2001 8:51 pm 
robinNov 18, 2001 11:18 pm 
Patrick MulvanyNov 19, 2001 2:42 am 
Aly S.P DharshiNov 19, 2001 11:30 am 
Aly S.P DharshiNov 19, 2001 11:33 am 
Actions with this message:
Paste this link in email or IM:
Paste this link in email or IM:
Atom feed for this thread
Paste this URL into your reader:
Subject:Re: [courier-users] Redundant IMAP serviceActions...
From:Les Stott (lst@rentokilinitial.com.au)
Date:Nov 18, 2001 8:40:40 pm
List:net.sourceforge.lists.courier-users

If you want redundancy you could setup a second server exactly the same as the first. Then use rsync to copy user maildirs across to the "backup" machine.

We used to have two servers that shared the role of mail, proxy and httpd. We used ip address aliases for these services and always made sure that only one of the servers ran one of the addresses at one time. However if we needed to bring a server down we could rsync the data across and enable the service on the backup machine. Worked really well and involved minimal interuption to users.

We have now changed that system to only having one server but it is a brand new compaq proliant ml370 with mirrored disks. this is enough for redundancy.

Regards,

Les Stott Systems Administrator Rentokil Initial lst@rentokilinitial.com.au (02) 9370 9348

This email is confidential. If you are not the intended recipient, you must not disclose or use the information contained in it. If you have received this in error, please advise the sender by return email and delete the material from your computer.

Rentokil Initial Pty Ltd ABN 98 000 034 597 does not warrant that any attachments are free from viruses or any other defects. You assume all liability for any loss, damage or other consequences which may arise from opening or using the attachments.

----- Original Message ----- From: robin <xiul@yahoo.com> To: courier users group <cour@lists.sourceforge.net> Sent: Monday, November 19, 2001 3:08 PM Subject: [courier-users] Redundant IMAP service

Hi ,

My boss has asked me to look into providing a redundant IMAP servers i.e if one IMAP server fails(due to some hardware problem perhaps), another one in another machine will kick off. From our paid users who are accessing the IMAP via our web interface, it will seem to them that nothing is wrong.

Currently, we 're runing courier-imap with qmail-ldap installation in linux 6.2 on a dell machine.

Has anyone done this before? What sort of technology sould be used here?

Obviously we need to use a "shared external hard disk" and may be linux clustering LVS(linux virtual server). Can an external hard disk be mounted simultaenously onto 2 linux machines? LVS load balances between the 2 IMAP servers which means the 2 servers will need to write to the shared hard disks at the same time but into different user directory, so they won't reading/writing same files. Is there a problem here?

Another way i think of is to have 2 different IMAP/Qmail servers with their own hard disks. We modify the codes for IMAP and Qmail so whatever changes made to the maildir of first machine get replicated to the second machine. Has this been done before?

Thanks in advance.

regards, roland

__________________________________________________ Do You Yahoo!? Find the one for you at Yahoo! Personals http://personals.yahoo.com

_______________________________________________ courier-users mailing list cour@lists.sourceforge.net Unsubscribe: https://lists.sourceforge.net/lists/listinfo/courier-users