On Thu, May 28, 2015 at 12:09 AM, <[email protected]> wrote: > > Hi folks. I spent a very frustrating time last night trying to figure > out why my systemd would not boot using systemd. I am using dracut and > its version is 041r2. Now what was happening is that the system would > get to the pre-init-queue -- and I even set the rd.break there, but > after that the system would not boot -- when I used debug it endlessly > said calling setl forever. Now it turned out that the problem was that > I had mistyped an rd.lv= line -- instead of ssd-files/usr I had > ssd-files/-usr . Now, what I would like to know is how could I tell > that it was trying to look for a non-existent lv? At the point of the > break. no lvm volumes were active, although strangely enough I saw a > e2fsck for the real root file system which was an lvm volume. I am > finding its generally hard to debug systemd problems, several other > times the system just sat there till I figured it out some other way. > > Any observations on this would be appreciated, but I don't want to get > into a flame war, I just want to minimize the down time.
Usually if you can get an emergency shell by adding "emergency" to the kernel command line (both GRUB and Gummiboot allow you to edit the kernel command line), then is easy to see what the problem is. My experience with LVM has been consistently pretty awful, which is why I don't use in any of my machines, but I suppose a systemctl --all --full will tell you what unit files have failed, and then you can journalctl -b -u them. Also journalctl -b by itself would tell you many times what the problem is. The only problem with the emergency shell is that sometimes is too early in the boot process for the keyboard drivers to have been loaded, but that is easily solved by adding a drivers+="" line to a conf file in /etc/dracut.conf.d. Also, and I cannot stress this enough, you never delete your old (and working) kernel+initramfs until you have tested the new one. I would also recommend to leave the entries for the old kernel+initramfs in the GRUB/Gummiboot menu, but you can manage without them. Finally, and this is tooting my own horn, maybe you could try kerninst[1]? It's a little script I started a couple of years ago to automatically compile and install my kernels and generate my initramfs'. I use it in all my machines, and now my kernel update is just a matter of eselecting the new version, and running kerninst. I follow ~amd64 vanilla-sources, so this is roughly every week or two. Beware, though, that I don't use LVM nor RAID nor Luks, but in theory if you have a working kernel+dracut+[grub|gummitboot] configuration, it should also work with them. Regards. [1] https://github.com/canek-pelaez/kerninst -- Canek Peláez Valdés Profesor de asignatura, Facultad de Ciencias Universidad Nacional Autónoma de México
