I tried to look at a dovecot.index.log and it was unreadable in a text editor. I didn't see anything in the wiki link about how to view the log.

It's not supposed to be human readable -- the point of this exercise was to check whether your indices are really out of date. You can perhaps compare the mtime of the index files and the mailbox. If they're close or the same, then your indices are not out of sync and don't require sync'ing.

So I guess I'll just be guilty of excessive optimizing. Should I run a daily doveadm index or resync?

You've skipped over the first 3 steps (is it really out of sync, is there a better way to avoid it, does the un-sync really cause probems) and went right to a solution for a possibly non-existent problem.

Be that as it may, the frequency of re-syncing is up to you. I have no idea how large your userbase is or how intensive this operation will be. If it takes only a minute, you could run it more frequently. If you're going through terabytes of data, less frequently.

I'm not quite convince you need it at all: I never had to do a global re-indexing except for a one-time dovecot initializing, or dealing with the odd crash that left indices in a unfixable state (which is more a bug than an unsync problem).

Joseph Tam <jtam.home@gmail.com>