Date: Tue, 22 May 2018 07:48:09 -0700 (PDT) From: "Rodney W. Grimes" <freebsd-rwg@pdx.rh.CN85.dnsmgr.net> To: Johannes Lundberg <johalun0@gmail.com> Cc: Warner Losh <imp@bsdimp.com>, freebsd-current <freebsd-current@freebsd.org> Subject: Re: How to check if not clean shutdown? Message-ID: <201805221448.w4MEm9ra030594@pdx.rh.CN85.dnsmgr.net> In-Reply-To: <CAECmPwu21YSFd4qp-ov1zpb_O1X5yVmQt0c5iqY7w6c4ijw-FA@mail.gmail.com>
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> On Tue, May 22, 2018 at 3:30 PM, Warner Losh <imp@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. utmp has one attempt at keeping track of this by recording a shutdown record. > > On Tue, May 22, 2018 at 7:57 AM, Johannes Lundberg <johalun0@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@freebsd.org mailing list > >> https://lists.freebsd.org/mailman/listinfo/freebsd-current > >> To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org > >> " > >> > > > > > _______________________________________________ > freebsd-current@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-current > To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org" > -- Rod Grimes rgrimes@freebsd.org
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