Hosting Quotas Gotcha

I am really liking Virtualmin, but just got bitten, hard, by an unexplained problem. Postfix started rejecting incoming mail, saying in the logfile (/var/log/maillog)

status=bounced (can't create user output file)

Well after much gnashing of teeth, it turns out that the user (me) was over quota. You can see this with:

# quota itsme.mydomain
Disk quotas for user itsme.mydomain (uid 536):
     Filesystem  blocks   quota   limit   grace   files   quota   limit   grace
      /dev/xvda   51200   51200   51200              73       0       0

Hmm... where are those extra files? Not anywhere in /home ... read on --Turns out, if you leave the "Scan for viruses?" checked (under "Enabled Features" on the "Edit Virtual Server" tab) then clamav will scan incoming email for viruses... and nearly instantly kill your default 50MB per-user quota... and this is nearly impossible to find, but go look in /tmp and you'll find /tmp/clamav-somebignumber as a directory with files (main.db, main.hdb, main.info, main.mdb, main.ndb) and they will be, oh, 15 megabytes in size. Ugh. Disable virus scanning and delete those files. Or else push your users' quotas up by maybe 100MB for the per-user virus databases.

Maybe there's a way to have clamav keep a system-wide virus database instead. That would be much more logical, it seems. Or how about leaving that up to users.

I still haven't found where to make "Scan for viruses" off by default for new domains.

You might also want to check the users' mail inboxes, which are located at:

/home/domain/homes/username/Maildir

where domain is the username for the domain, and username is the user's name inside the domain. You will recognize these because the POP or IMAP login for that user is domain.username.