[systemd-devel] Samba Config Reload

[Wols Lists]

On 09/04/2022 09:00, Yolo von BNANA wrote:
> Can you please explain this in more Detail?
> 
> What does this mean: " "systemctl reload" will basically return
> immediately without the reload being complete"?
> 
> And what is an Example for an synchronous command for ExecReload=
> 
Do you understand the difference between "synchronous" and 
"asynchronous"? The words basically mean "aligned in time" and "without 
timed alignment".

Think of writing to files. In the old days of MS-DOS et al, when your 
program called "write", the CPU went off, saved the data to disk, and 
returned to your program. That's "synchronous", all nicely ordered in 
time, and your program knew the data was safe.

Now, when your linux program calls write, linux itself replies "got it", 
and your program goes off knowing that something else is going to take 
care of actually saving the data to disk - that's "asynchronous". Except 
that sometimes the program needs to know that the data HAS been safely 
squirreled away (hence all these fsync calls).

So when systemd calls ExecReload *A*synchronously, it goes off and fires 
off a load more stuff, knowing that the ExecReload IS GOING (future 
tense) to happen. What the previous poster wanted was a synchronous 
ExecReload, so that when systemd goes off do the next thing, the 
ExecReload HAS ALREADY HAPPENED (past tense). (Which in general is a bad 
thing because it *seriously* knackers performance).

Cheers,
Wol