Re: How to check if not clean shutdown?

From: Johannes Lundberg <johalun0_at_gmail.com>
Date: Tue, 22 May 2018 15:35:37 +0100
On Tue, May 22, 2018 at 3:30 PM, Warner Losh <imp_at_bsdimp.com> wrote:

> You can't, in general. By the time the boot loader starts, all knowledge
> of past boots is gone, unless specific counter-measures were put in place.
>
> However, if root is UFS and read/write in your box, it will be unclean on
> anything but a clean shutdown/reboot. If it's read-only, ZFS or NFS
> mounted, then you can't use this method.
>
> If you have UEFI, you can set a UEFI variable on shutdown and clear it on
> boot. If it's not there on boot, you had an unclean shutdown. You could do
> the same with a file in a r/w filesystem that doesn't record clean/unclean
> (like ZFS or NFS).
>
> Locally, we have hacks to IPMI to record kernel crashes in the IPMI log,
> but that's kinda specific to the BMC we have on our boards...
>
> Warner
>

I see. Thanks for the quick reply.
I guess I can add a dummy file somewhere that I delete in a shutdown hook.


>
>
> On Tue, May 22, 2018 at 7:57 AM, Johannes Lundberg <johalun0_at_gmail.com>
> wrote:
>
>> Hi
>>
>> In the boot process on my test machines I'd like to do different things
>> depending on the last run was a clean shutdown or kernel panic. Where/How
>> can I get this information?
>>
>> Thanks!
>> _______________________________________________
>> freebsd-current_at_freebsd.org mailing list
>> https://lists.freebsd.org/mailman/listinfo/freebsd-current
>> To unsubscribe, send any mail to "freebsd-current-unsubscribe_at_freebsd.org
>> "
>>
>
>
Received on Tue May 22 2018 - 12:36:19 UTC

This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:41:16 UTC