On 13-Sep-2009, at 18:27, Sahil Tandon wrote:
On Sun, 13 Sep 2009, LuKreme wrote:
My question is what is the best way to actually migrate the mail and
the users to the new machine without losing mail? WOuld it be a good
idea (or even possible) to run the two machines in parallel for a
time, having all new mail go to both of them so I can then remove
the old machine once I see that everything is working?
Just delivering new mail in parallel is not enough; what about users'
existing mail?
rsync should handle that just fine. And actually, I will pt this
server into play right away and setup an sync backup to it anyway, so
by the time I get started there will be a copy of all users mail on it
that is no more than 6 hours old.
The last time I did a migration to a new machine 1) someone else was
in charge 2) we moved the hard drive so we didn't have to move
users/mail 3) we were offline for an entire weekend.
Does this machine serve both IMAP and SMTP?
Yep.
Depending on how many users
you have to move, just select a bunch and spool mail for them on the
current Postfix box while you rsync their IMAP mailboxes to the new
box.
Probably not enough users to make that necessary, but that might be a
way to run the two machines in parallel for a little while.
Create a transport map to push their queued and incoming mail to the
new
server.
Oh? so I could still have the mail come in to mail.covisp.net and then
have a transport that redirected all the incoming mail to mail2… ?
How would it verify local users?
If users continue to connect to the old hostname for IMAP,
proxy their particular connections so they don't even notice they're
reading mail on a new machine. Repeat this process until all
mailboxes
have been moved. Then flip DNS (i.e. MX records, imap.foo.bar,
smtp.foo.bar, et cetera) to point to the new machine and retire the
old
one.
That sounds very clever, thanks. Good to know I'm not way off base in
my thinking.
Thanks for the pointers.
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