[Dovecot] Best way to change index location on mdbox

[Timo Sirainen]

On Sat, 2012-05-19 at 20:43 +0200, Patrick Westenberg wrote:
> Timo Sirainen schrieb:
> 
> > You must not lose indexes with mdbox or you'll lose message flags and
> > mails may also end up going to wrong mailboxes.
> 
> Yes, have been there but this behaviour is confusing me as I find 
> conflicting information in the wiki:
> 
> http://wiki2.dovecot.org/IndexFiles
> "If index files are missing, Dovecot creates them automatically when the 
> mailbox is opened."

This and maybe other parts of documentation was written before dbox
format was created. It's true for maildir/mbox, but not for dbox. I
updated that page now.

> http://wiki2.dovecot.org/MailboxFormat/dbox
> This data cannot be automatically recreated, so it is important that 
> Index files are treated with the same care as message data files.
> 
> So why do I lose mails if I delete index file but if e.g. a director
> connects to a backend with non existing index files yet, they are created.

Losing mails probably happens only when imap crashes while it's trying
to recreate the indexes. Once that bug is fixed it should happen.

But you really don't want any of this with mdbox, not deleting index
files or having per-backend index files.