User Mailboxes Migration
Hi,
I have been reading section 2.5 of the Administration Guide. The options to migrate user mailboxes are as follow:
1. To Migrate User Mailboxes from One Messaging Server to Another While Online
2. To Move Mailboxes Using an IMAP client
3. To Move Mailboxes Using the moveuser Command
4. To Move Mailboxes Using the imsimport Command
It appears to me that all methods require both old and new mail server running during the migration. I just wonder how could both old and new mail server having a FQDN of "mail.example.com" run at the same time without problem? Or you simply turn off DNS and use only IP addresses.
Assuming you use a different name for the new and old mail server, how do I go about changing the name? For example, I can think of two cases.
1) Setup new mail server as mail.example.com
2) Change old mail server to old.example.com
3) Turn on new mail server
4) Perform migration
5) Shutdown old.example.com
-OR-
1) Setup new mail server as new.example.com
2) Perform migration
3) Shutdown old mail (mail.example.com)
4) Change new mail server to mail.example.com
Has anybody use method 3 in the above two cases? Is it the best way to migrate user mailboxes?
Thank you.
# 1
Hi,
I migrated a whole production setup successfully with folowing approach:
Assumptions
Both servers would use same hostname/IP/DNS names
there is no MX change
1. Installed the new server in a private network and connected this server to old throufg a cross cable with whatever IP/subnet
This resolves the IP conflict -- now both servers can have same IP same hostname and the old production can still be up and running
2. Dumped the ldif of users (both PAB and Usergroup from old server to new server ( db2ldif cmd with ldapmodify used )
Now the users of old server are there in the new server too -- but without mails andno mails transactions are happening to the new server
3. imsbackup/ imsrestore the actual mails through cross cable link
Now the new server has fully updated users as well as mails
4. Disconnect the old server and connect the new server to production network
I had a downtime for 20 min for migration of 5000 users.
Same process would follow for servers with diferent names -- but if domain names change you have to edit the ldif dumps first before importing that is simple with awk/sed/perl whatever u use
Thanks
# 2
Hi,
Thanks for sharing. I have some follow-up questions.
1. You mentioned by using a cross over cable between the two servers, they can have the same IP and host name. As far as I know, the servers at both ends of a cross over cable must have two different IPs.
Even if two different IPs are used, how are the DNS conflict resolve? Assuming you are using /etc/hosts, are you making entries similar to the following?
#
# Internet host table
#
127.0.0.1localhost
# migrate to
172.16.4.248mail.example.com mail loghost
# migrate from
172.16.3.248mail.example.com mail
2. I can see that in your case (using imsbackup and imsrestore), it is perfectly fine to backup mail stores from the old server, put it in external disk and restore to the new mail store. No network connection is necessary to do the job. Am I correct?
Thank you.
