Boot fails after pacman -Syu [SOLVED]

Question

Hello forums,
I did a full system upgrade two days ago. Getting this on boot
early console in decompress_kernel
Decompressing Linux... Parsing ELF... done.
Booting the kernel.
:: running early hook [udev]
:: running early hook [lvm2]
:: running hook [udev]
:: Triggering uevents...
:: running hook [v86d]
:: running hook [xfs]
:: performing fsck on '/dev/mapper/vg_phobos-lv_root'
/sbin/fsck.xfs: XFS file system.
filesystem '' cannot be mounted, unable to open the datases
:: running cleanup hook [lvm2]
:: running cleanup hook [udev]
ERROR: Failed to mount the real root device
Bailing out, you are on your own. Good luck.
sh: can't access tty: job control turned off
[rootfs /]#
LVM is fine and root partition is fine. I can mount it manually from initramfs console.
Running "./init" or exit at the console results in kernel panic, root mounted in /new_root or not.
pacman -Syu went without problems.
Thanks in advance.
Last edited by zb10948 (2013-11-10 18:00:52)

Answer 1

The issue was initcpio ZFS hook. Evidently, if root partition isn't on ZFS the boot breaks.
In this case, ZFS should be handled by systemd service which will mount ZFS partitions from userland.
Procedure :
inside initcpio console, manually mount the root filesystem, chroot to it and run init
mount /dev/path/to/root /new_root
switch_root /new_root /sbin/init
System boots. Afterwards, remove zfs hook from /etc/mkinitcpio.conf and rerun mkinitcpio. Also check that zfs.service system unit is active and enabled.
Last edited by zb10948 (2013-11-10 18:00:37)