OK, I thought you were saying it only rebooted when you weren't there to watch it.
When I encountered this behavior recently, I found there was corruption in the APFS snapshots. Unfortunately, I found this only after the machine committed total hara-kiri, because Disk Utility was entirely too incompetent to detect any problem at all, and DiskWarrior still can't handle APFS. The problem was entirely undetectable until macOS finally diagnosed it by refusing to boot at all.. and by that time it was impossible for macOS to correct. An early symptom of the problem was that Time Machine backups had (silently) stopped running — they'd launch, spend a lot of time "preparing," then stop with no message. Heroic attempts to diagnose/correct that problem also failed completely, but subsequent experience indicates it was another effect of the same corruption. My advice is for you to keep an actual clone copy up to date (on a non-APFS drive) so you'll have something to recover from on the day macOS finally wakes up and realizes, "Looka that, I'm dead!" > On Nov 19, 2020, at 5:50 PM, Jeff Weinberger <j...@jeffweinberger.com> wrote: > > > On Thu, Nov 19, 2020 at 7:18 PM Macs R We <macs...@macsrwe.com > <mailto:macs...@macsrwe.com>> wrote: > Do you have automatic updating enabled? If the system performs an automatic > update that requires a reboot, it will reboot. > > I have automatic updates enabled for things other than system updates, so > there should never be a reboot and there never was one in any previous > version before Big Sur. > > Also the time it rebooted while I was working was very sudden - it didn't > shut down in an orderly fashion. It just instantly went black and then the > apple logo appeared. > > > > On Nov 19, 2020, at 11:03 AM, Jeff Weinberger <j...@jeffweinberger.com > > <mailto:j...@jeffweinberger.com>> wrote: > > > > I upgraded my iMac (21.5 inch, Late 2015) to Big Sur (11.0.1). Since then > > it's been restarting every now and then. I've noticed it tends to happen > > when I've been away from it for a while (like overnight, or if I go out for > > a few hours), but it's also happened once while I was working. It's > > probably happened 4-5 times since I upgraded 3 days ago. > > > > Is this a known bug? Has anyone seen this? > > _______________________________________________ > > MacOSX-talk mailing list > > MacOSX-talk@omnigroup.com <mailto:MacOSX-talk@omnigroup.com> > > https://www.omnigroup.com/mailman/listinfo/macosx-talk > > <https://www.omnigroup.com/mailman/listinfo/macosx-talk> > > _______________________________________________ > MacOSX-talk mailing list > MacOSX-talk@omnigroup.com <mailto:MacOSX-talk@omnigroup.com> > https://www.omnigroup.com/mailman/listinfo/macosx-talk > <https://www.omnigroup.com/mailman/listinfo/macosx-talk>
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