On 22/11/14 09:43, Ross Boylan wrote: > On Thu, Nov 20, 2014 at 9:11 PM, Scott Ferguson > <scott.ferguson.debian.u...@gmail.com> wrote: >> On 21/11/14 15:13, Ross Boylan wrote: >>> Over the last week I've repeatedly found my machine unbootable, >>> in the sense I couldn't get to a working system without >>> intervention. Sometimes I couldn't even get the grub2 menu. >> >> >> Tick > > I don't understand what you mean by tick.
That I had the same symptom. (as Lisi has noted). > > [snip] > >>> Could changing the boot order in the BIOS change the drive >>> mappings and screw up grub that way? >> >> Yes. >> > Whichever drive I booted off of sda and sdb always referred to the > same physical devices. And that was even though I booted into > different operating system instances. > > But I guess the fact that linux can keep the names safe (via udev > remembering serial numbers I suspect) doesn't really speak to the > drive mappings that grub sees in its early operation. > > [snip] > >> >> I've had a 'similar' problem, in my case it was solved with:- >> grub-install /dev/$Whatever > > I either executed that explicitly or, I assume, the grub package > installation machinery did it for me. But I still had trouble. If you executed that explicitly, see my comment about double-checking device names and BIOS boot order. If you didn't explicitly tell grub-install where to install - it'll likely just put it back in the same place (and not solve the problem?). > > grub needs to know where it should jump to. Yes. > I don't know how it can figure that out from inside a chroot. The same way it "figures it out" when not in a chroot? > For example, say /boot inside the chroot is mounted from sdb2. To the > chroot, it's just part of the filesystem. How is grub-install to > figure out that, when it loads from the start of the disk, it should > look for the grub directory (not /boot/grub) of the appropriate > partition? That depends on what you mounted in your chroot. locate/mlocate/find devicemap 'might' be instructive. > The only possibility I can think of would be that it looks in > /etc/fstab. Perhaps (or mtab)? I haven't done more than glance at info grub-setup so I can't say I know how device map is created (only that I know how I resolved a similar problem). >> >> If the problem is GRUB, and you are actually booting from sdb (due >> to the BIOS settings making it the boot device. Did you try the following? >> >> Note: double check device names (you can use the GRUB device name) >> with the mount command and use SMART to determine which device it >> the one set to boot from in the BIOS. >> >> >> Hope that helps. >> >> >> Kind regards > > Thanks for your response. Ross . > Kind regards -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: https://lists.debian.org/546fdd42.3060...@gmail.com
