[systemd-devel] more verbose debug info than systemd.log_level=debug?

[Michael Chapman]

On Mon, 10 Apr 2017, Lennart Poettering wrote:
> On Mon, 10.04.17 17:21, Michael Chapman (mike at very.puzzling.org) wrote:
>
>>> Or, I think, when pivoting back to the shutdown-initramfs. (Though then you
>>> also need the shutdown-initramfs to run `fsfreeze`, I guess?)
>>
>> No, I don't think it should be done then. If a filesystem is still in use,
>> then doing a freeze there would likely make any processes still using it
>> unkillable. And doing a freeze followed by a thaw doesn't gain us much, we'd
>> still need to do another freeze at the end of shutdown-initramfs.
>
> Hmm? Are you saing that on XFS you might even see corruption on files
> that weren't accessed for write since the last freeze if you forget to
> freeze when shutting down?

No, I'm not saying that at all.

> I mean, unless the initrd hooks modify the boot loader having done
> FIFREEZE once sounds safe enough, no?

Mantas Mikulėnas suggested doing a freeze on the pivot back to the 
shutdown-initramfs. But that's no good: any argv[0][0] == '@' processes 
could be writing to the filesystems then.

This is why I've been stressing that the filesystem freezes (and thaws 
too, if necessary) should only happen right before the reboot(2) syscall.