[gpfsug-discuss] wait for mount during gpfs startup

[Skylar Thompson]

On Thu, Apr 30, 2020 at 12:50:27PM +0200, Ulrich Sibiller wrote:
> Am 28.04.20 um 15:57 schrieb Skylar Thompson:
>  >> Have you looked a the mmaddcallback command and specifically the file system mount callbacks?
> 
>  > We use callbacks successfully to ensure Linux auditd rules are only loaded
>  > after GPFS is mounted. It was easy to setup, and there's very fine-grained
>  > events that you can trigger on:
> 
> Thanks. But how do set this up for a systemd service? Disable the dependent service and start it
> from the callback? Create some kind of state file in the callback and let the dependent systemd
> service check that flag file in a busy loop? Use inotify for the flag file?

In the pre-systemd days, I would say just disable the service and let the
callback handle it. I do see your point, though, that you lose the other
systemd ordering benefits if you start the service from the callback.
Assuming you're still able to start the service via systemctl, I would
probably just leave it disabled and let the callback handle it.

In the case of auditd rules, it's not actually a service (just a command
that needs to be run) so we didn't run into this specific problem.

-- 
-- Skylar Thompson (skylar2 at u.washington.edu)
-- Genome Sciences Department, System Administrator
-- Foege Building S046, (206)-685-7354
-- University of Washington School of Medicine