-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Sat, 3 May 2003 14:42:08 -0400 (EDT), Robert P. J. Day wrote: > (perhaps related to an earlier issue as to why one needs > an initrd when using ext3 ...) > > earlier today, when demonstrating to a class how to rebuild > a kernel, i suggested that one could avoid having to deal with > creating an initrd.img if one built all necessary drivers into > the kernel. > > since we were using ext3 filesystems and logical volumes, > i was very careful to tell everyone to add these features to > their kernel, and not leave them as modules. since they all > did that, i told them to skip building an initrd.img and > just reboot. > > bad idea -- the boot hung at trying to mount the root > filesystem. i couldn't figure out why since the kernel had > clearly loaded and started to run, so what was the problem? > > one student just added the "initrd" line to her grub.conf > file for that kernel image, and it worked fine. puzzling. > so i ripped open that initrd.img and found just ext3.o, > jbd.o and lvm-mod.o. but why were these needed in the > initrd? > > as a test, i ran "mkinitrd" against the new kernel, > got my new initrd.img, and opened it up to find ... > no module at all. not surprising since everything was > in the kernel, and "mkinitrd" was smart enough to figure > that out. but using that module-less initrd.img got the > boot to work. > > what gives? i checked the /etc/fstab, and it turns > out that the /boot filesystem (a real primary partition, > not a logical volume) was listed with a LABEL field, > but even changing that back to a /dev entry didn't > fix things. > > so why is initrd.img necessary for LVs even when it has > no modules? Did you use partition labels in /etc/grub.conf? If so, the kernel would fail mounting the root partition, since it is the "mount" command in the initial RAM-disk that supports partition labels. - -- -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.7 (GNU/Linux) iD8DBQE+tBWZ0iMVcrivHFQRAjqeAJ0STQXNBHRWZw/NqPTUS8+5J2kM5ACeLyKF +z2Hqfy+jVrlLTRziG31NYo= =4eBf -----END PGP SIGNATURE-----
