dovecot.index.log files: what are they?

[Joseph Tam]

Thomas Klausner writes:

>> RTFM: http://wiki2.dovecot.org/IndexFiles
>
> Thanks, but I had read this.
>
> I still don't know what they are good for, why they stay there for
> days and if I can remove them. After all, they are not the caches, but
> some "transaction logs" (I don't know what this is).

Re-read the page, all the way to the bottom.

Interpreting the last section:

The transaction log records recent changes to a mailbox, and together
with the index, gives the current state of the mailbox.  This is an I/O
optimization so that mailbox states changes are quickly updated without
having to compare an entire index file with the last (in-memory?) index.
For large mailboxes, this can save a lot of I/O.

It may persist because updates to the indices are not done immediately
(again, possibly to reduce I/O), so the current mailbox state is reflected
by the index file *and* deltas in the transaction log.

I suspect that you could remove the transaction logs (if you do not use
dbox) and dovecot should rebuild them (or more likely, rebuild the indices).

Joseph Tam <jtam.home at gmail.com>