Hi, I have sporadic messages on my server about an account getting an out of memory error:

Fatal: master: service(imap): child 17910 returned error 83 (Out of memory (service imap { vsz_limit=325 MB }, you may need to increase it) - set CORE_OUTOFMEM=1 environment to get core dump)

In response, I raised the limit from 256MB up to 325. That didn’t seem to help. The server has only 512 MB of RAM so I’m afraid to go much higher.

I googled around a bit and some people are saying that when the dovecot.index.cache grows too large, it can cause these errors. The imap account has a dovecot.index.cache file that is 167 MB which seems to be well below the limit (but maybe it is compressed?). So I’m not entirely sure as to what the underlying problem is.

So before upgrading to the server to 1024 MB of ram and going on a wild goose chase, I just want to get input on whether I have positively identified the problem and whether there might be something else I can do to manage this problem.