[Dovecot] quick question about fs quota overhead in plugin

[Adam McDougall]

Last night I enabled imap_quota so dovecot could report usage reported
by disk quota.  I don't intend to actually use the quota plugin to place
any limits anytime soon though.  How much overhead does this add to 
normal operations that allocate disk space?  Ideally I'd like a situation
where the only overhead is incurred when the user uses the mail client to
specifically check their usage.  Is that possible, and/or is there a better
way to do this?  If it does cause general overhead on the NFS filer, I could
just accept it until/unless I feel it becomes a burden I cannot bear.

mail_plugins = acl fts fts_squat quota imap_quota
...
quota = fs
...