On Mon, Apr 21, 2014 at 7:44 PM, Walter Dnes <waltd...@waltdnes.org> wrote: > On Mon, Apr 21, 2014 at 09:38:44AM +0100, Peter Humphrey wrote >> On Monday 21 Apr 2014 00:55:56 yac wrote: >>> On Sat, 19 Apr 2014 13:54:07 +0100 >>> Peter Humphrey <pe...@prh.myzen.co.uk> wrote: >>>> >>>> The installation handbook used to include a command to >>>> write /etc/mtab in the chroot by grepping the host mtab >>> >>> It was part of grub-install, now grub legacy >>> >>> https://www.gentoo.org/doc/en/handbook/handbook-amd64.xml?part=1&chap=10#doc >>> _chap4 >> >> Yes, thanks, a couple of people posted what it says here the other >> day. Now I'm puzzling over whether it's good advice. >> >> For instance, suppose I want to reinstall the chroot in which I keep >> an image of my Atom box here on my workstation. Then /etc/mtab has: >> /dev/md5 / [...] >> but once I chroot into /mnt/atom, where the image lives, that's wrong and >> should be: >> /dev/mapper/vg7-atom / [...] >> because vg7-atom is now the root of the file system. >> >> Does the handbook need an update? Or maybe it's right after all >> because when grub runs its installer it's unconcerned with where >> it's invoked from. >> >> [Wanders off stage-left, muttering and scratching his head...] > > *AFTER YOU CHROOT* what are the contents of /proc/self/mounts and > /proc/mounts ? Can you copy either of them into /etc/mtab and have the > correct result?
I duped a Gentoo VM on my laptop, launched it, and looked at the output of "grep ' / ' /proc/mounts" in the "/mnt" chroot after mounting "/mnt/proc" before and after the chroot, which is unsurprisingly the same. What are you trying to find out? I haven't used lilo for 12 years at least. Does it operate using "/proc/self/mounts" or "/etc/mtab"? mount/umount, for example, use "/etc/mtab". grub-install, AFAIR, uses "/proc/self/mountinfo" as well as the "/sys/devices/" hierarchy. localhost ~ # mount /dev/vdb1 /mnt localhost ~ # mount -t proc proc /mnt/proc localhost ~ # chroot /mnt localhost / # grep ' / ' /proc/mounts rootfs / rootfs rw 0 0 /dev/disk/by-uuid/fe087ffc-ccb6-48ce-a8f7-a3a6d0fb20e3 / xfs rw,relatime,attr2,inode64,noquota 0 0 /dev/vdb1 / xfs rw,relatime,attr2,inode64,noquota 0 0 localhost / # exit exit localhost ~ # umount /mnt/proc localhost ~ # chroot /mnt localhost / # mount -t proc proc /proc localhost / # grep ' / ' /proc/mounts rootfs / rootfs rw 0 0 /dev/disk/by-uuid/fe087ffc-ccb6-48ce-a8f7-a3a6d0fb20e3 / xfs rw,relatime,attr2,inode64,noquota 0 0 /dev/vdb1 / xfs rw,relatime,attr2,inode64,noquota 0 0 localhost / # exit exit localhost ~ # xfs_admin -u /dev/vda1 UUID = fe087ffc-ccb6-48ce-a8f7-a3a6d0fb20e3 localhost ~ #
