Emails redownloading

[B. Reino]

On 2019-04-12 07:43, azurit--- via dovecot wrote:
> Hi,
> 
> recently, we had a problem on one of our mail servers and, after
> reboot, HDD with emails wasn't mounted into system. Until we fixed it,
>  LOTS of users logged in (Dovecot allowed login and recreated
> directory  structure of mailboxes) and saw empty mailboxes. Now they
> are  redownloading all email, which isn't fun, as it's about 2 TB of
> data.
> 
> Anyway, is there a way how to prevent this in the future? Can i set
> Dovecot to disallow logins in such situations? Thanks.

You didn't tell which OS or init system you are using.
With systemd, you can add use "systemctl edit dovecot" and use:

[Unit]
RequiresMountsFor=/path/to/your/mounted/mailbox

This way dovecot will be started when the directory has been mounted.

IMHO, and with no offence intended, if you can't control your system 
initialization, then you should not start daemons automatically, i.e. 
you should take the role of systemd.

Cheers.