[Dovecot] Maildirs location migration

[Thomas Hummel]

On Wed, Apr 10, 2013 at 09:21:40PM +0300, Timo Sirainen wrote:

> Not if you kick the users out at the correct time:
> 
>  - dsync
>  - switch user to new format
>  - kick users
>  - final dsync
> 
> It doesn't matter if new connections arrive during the final dsync,
> because they are using the new format already. dsync merges changes, it
> doesn't destroy any changes.

It doesn't destroy changes but the user may see an incorrect state for a small
amount of time, doesn't he ?

For instance (using dsync to change Maildir location from file1 to filer2) :

  . Maildir in source : message tagged as New
  . initial dsync
  . user read the message in the source, message is now tagges as Read
  . switch user to Maildir in destination
  . kick user
  . user reconnects and sees, in destination, the message he just read tagged
    as New as long as the final dsync is not finished

?

-- 
Thomas Hummel 	    | Institut Pasteur
<hummel at pasteur.fr> | Groupe Exploitation et Infrastructure