Dominic Raferd:
> I am using incrond to monitor an mbox file (in /var/mail) for changes, but
> it is failing to trigger when postfix adds an incoming mail to the file.
Possible causes:
- Your file system does not set the file mtime when Postfix appends
to the file. Fix: don't disable mtime updates for append operations.
- There is a clock drift problem where the host with Postfix has
different time than the host with the file system. Fix: run NTP on
both hosts.
> (It triggers fine however if I touch the file.)
>
> I may be barking up the wrong tree but I wonder if this is because instead
> of merely appending to the existing mbox file, postfix/local rewrites the
> file so that its inode changes (which I know breaks incrond's ability to
> monitor a file). If so, is there a way to get postfix to append to the file
> without changing the inode, and if so what are the disadvantages?
Have you verified that the inode number changes?
Postfix opens an mbox file with O_APPEND mode which is standardized
by the POSIX API. If that causes the file inode number to change,
then you need to use a different file system.
Wietse
> I have postfix 3.3.0, local has default settings, and /var/mail is on
> filesystem ext4 (options rw,relatime,data=ordered) under Ubuntu 18.04.1
> (GNU/Linux 4.15).
