Upgrade and Migration

[Carson Gaspar]

Ben Carter wrote:
> Carson Gaspar wrote:
>> Ben Carter wrote:
>>
>> You have to do the _exact_ same thing with imapsync, unless you want 
>> to lose email.
> 
> As has already been pointed out, you are incorrect.  The order is:
> 
> [Pre-create inboxes with large quotas on new server]
> 
> 1. Shut off mail delivery to old server
> 2. Shut off imapd on old server.
> 3. Bring up new server with imapd running
> 4. Start mail delivery to new server.
> 5. Start imapd on old server with a new IP address or bound to a 
> nonstandard port so MUAs will not get to it.
> 6. Migrate data using imapsync.
> 
> And your service can be down literally for only a few minutes if you 
> plan correctly.

You have chosen to have users see missing data. You have made a tradeoff between 
correctness and length of downtime by bringing up your new server in a client 
visible way before you sync your data. I (foolishly, it seems) assumed that you 
wouldn't want your users to log in to empty mailboxes, and would leave your new 
server non-user-visible until your sync completed.

-- 
Carson