[SOLVED] linux-lts GRUB "Unable to find device" error

Question

I installed linux-lts, reconfigured GRUB, and created an initial ramdisk env,
# pacman -S linux-lts
# grub-mkconfig -o /boot/grub/grub.cfg
# mkinitcpio -p linux-lts
I'm able to load the linux-lts kernel from rEFInd (dual booting with MacOS), but I get the error:
Warning: /lib/modules/3.14.17-1-lts/modules.devname not found - ignoring
ERROR: device "UUID=df842c36-41f7-4606-b219-7879cf1c4825" not found
ERROR: Unable to find root device "UUID=df842c36-41f7-4606-b219-7879cf1c4825"
and am dropped into  a recovery shell.
However,
% ll /lib/modules/3.14.17-1-lts/modules.devname ~
-rw-r--r-- 1 root root 411 Aug 26 13:20 /lib/modules/3.14.17-1-lts/modules.devname
so at least the file exists.
Here's the specific lines from grub.cfg pertaining to linux-lts :
# grep linux-lts /boot/grub/grub.cfg
linux /boot/vmlinuz-linux-lts root=UUID=df842c36-41f7-4606-b219-7879cf1c4825 rw quiet systemd.show_status=0
initrd /boot/initramfs-linux-lts.img
menuentry 'Arch Linux, with Linux linux-lts' --class arch --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-linux-lts-advanced-df842c36-41f7-4606-b219-7879cf1c4825' {
echo 'Loading Linux linux-lts ...'
linux /boot/vmlinuz-linux-lts root=UUID=df842c36-41f7-4606-b219-7879cf1c4825 rw quiet systemd.show_status=0
initrd /boot/initramfs-linux-lts.img
menuentry 'Arch Linux, with Linux linux-lts (fallback initramfs)' --class arch --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-linux-lts-fallback-df842c36-41f7-4606-b219-7879cf1c4825' {
echo 'Loading Linux linux-lts ...'
linux /boot/vmlinuz-linux-lts root=UUID=df842c36-41f7-4606-b219-7879cf1c4825 rw quiet systemd.show_status=0
initrd /boot/initramfs-linux-lts-fallback.img
and here is the complete grub.cfg
### BEGIN /etc/grub.d/00_header ###
insmod part_gpt
insmod part_msdos
if [ -s $prefix/grubenv ]; then
load_env
fi
if [ "${next_entry}" ] ; then
set default="${next_entry}"
set next_entry=
save_env next_entry
set boot_once=true
else
set default="0"
fi
if [ x"${feature_menuentry_id}" = xy ]; then
menuentry_id_option="--id"
else
menuentry_id_option=""
fi
export menuentry_id_option
if [ "${prev_saved_entry}" ]; then
set saved_entry="${prev_saved_entry}"
save_env saved_entry
set prev_saved_entry=
save_env prev_saved_entry
set boot_once=true
fi
function savedefault {
if [ -z "${boot_once}" ]; then
saved_entry="${chosen}"
save_env saved_entry
fi
function load_video {
if [ x$feature_all_video_module = xy ]; then
insmod all_video
else
insmod efi_gop
insmod efi_uga
insmod ieee1275_fb
insmod vbe
insmod vga
insmod video_bochs
insmod video_cirrus
fi
if [ x$feature_default_font_path = xy ] ; then
font=unicode
else
insmod part_gpt
insmod ext2
set root='hd0,gpt4'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt4 --hint-efi=hd0,gpt4 --hint-baremetal=ahci0,gpt4 df842c36-41f7-4606-b219-7879cf1c4825
else
search --no-floppy --fs-uuid --set=root df842c36-41f7-4606-b219-7879cf1c4825
fi
font="/usr/share/grub/unicode.pf2"
fi
if loadfont $font ; then
set gfxmode=auto
load_video
insmod gfxterm
fi
terminal_input console
terminal_output gfxterm
if [ x$feature_timeout_style = xy ] ; then
set timeout_style=menu
set timeout=5
# Fallback normal timeout code in case the timeout_style feature is
# unavailable.
else
set timeout=5
fi
### END /etc/grub.d/00_header ###
### BEGIN /etc/grub.d/10_linux ###
menuentry 'Arch Linux' --class arch --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-df842c36-41f7-4606-b219-7879cf1c4825' {
load_video
set gfxpayload=keep
insmod gzio
insmod part_gpt
insmod ext2
set root='hd0,gpt4'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt4 --hint-efi=hd0,gpt4 --hint-baremetal=ahci0,gpt4 df842c36-41f7-4606-b219-7879cf1c4825
else
search --no-floppy --fs-uuid --set=root df842c36-41f7-4606-b219-7879cf1c4825
fi
echo 'Loading Linux linux-lts ...'
linux /boot/vmlinuz-linux-lts root=UUID=df842c36-41f7-4606-b219-7879cf1c4825 rw quiet systemd.show_status=0
echo 'Loading initial ramdisk ...'
initrd /boot/initramfs-linux-lts.img
submenu 'Advanced options for Arch Linux' $menuentry_id_option 'gnulinux-advanced-df842c36-41f7-4606-b219-7879cf1c4825' {
menuentry 'Arch Linux, with Linux linux-lts' --class arch --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-linux-lts-advanced-df842c36-41f7-4606-b219-7879cf1c4825' {
load_video
set gfxpayload=keep
insmod gzio
insmod part_gpt
insmod ext2
set root='hd0,gpt4'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt4 --hint-efi=hd0,gpt4 --hint-baremetal=ahci0,gpt4 df842c36-41f7-4606-b219-7879cf1c4825
else
search --no-floppy --fs-uuid --set=root df842c36-41f7-4606-b219-7879cf1c4825
fi
echo 'Loading Linux linux-lts ...'
linux /boot/vmlinuz-linux-lts root=UUID=df842c36-41f7-4606-b219-7879cf1c4825 rw quiet systemd.show_status=0
echo 'Loading initial ramdisk ...'
initrd /boot/initramfs-linux-lts.img
menuentry 'Arch Linux, with Linux linux-lts (fallback initramfs)' --class arch --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-linux-lts-fallback-df842c36-41f7-4606-b219-7879cf1c4825' {
load_video
set gfxpayload=keep
insmod gzio
insmod part_gpt
insmod ext2
set root='hd0,gpt4'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt4 --hint-efi=hd0,gpt4 --hint-baremetal=ahci0,gpt4 df842c36-41f7-4606-b219-7879cf1c4825
else
search --no-floppy --fs-uuid --set=root df842c36-41f7-4606-b219-7879cf1c4825
fi
echo 'Loading Linux linux-lts ...'
linux /boot/vmlinuz-linux-lts root=UUID=df842c36-41f7-4606-b219-7879cf1c4825 rw quiet systemd.show_status=0
echo 'Loading initial ramdisk ...'
initrd /boot/initramfs-linux-lts-fallback.img
menuentry 'Arch Linux, with Linux linux' --class arch --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-linux-advanced-df842c36-41f7-4606-b219-7879cf1c4825' {
load_video
set gfxpayload=keep
insmod gzio
insmod part_gpt
insmod ext2
set root='hd0,gpt4'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt4 --hint-efi=hd0,gpt4 --hint-baremetal=ahci0,gpt4 df842c36-41f7-4606-b219-7879cf1c4825
else
search --no-floppy --fs-uuid --set=root df842c36-41f7-4606-b219-7879cf1c4825
fi
echo 'Loading Linux linux ...'
linux /boot/vmlinuz-linux root=UUID=df842c36-41f7-4606-b219-7879cf1c4825 rw quiet systemd.show_status=0
echo 'Loading initial ramdisk ...'
initrd /boot/initramfs-linux.img
menuentry 'Arch Linux, with Linux linux (fallback initramfs)' --class arch --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-linux-fallback-df842c36-41f7-4606-b219-7879cf1c4825' {
load_video
set gfxpayload=keep
insmod gzio
insmod part_gpt
insmod ext2
set root='hd0,gpt4'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt4 --hint-efi=hd0,gpt4 --hint-baremetal=ahci0,gpt4 df842c36-41f7-4606-b219-7879cf1c4825
else
search --no-floppy --fs-uuid --set=root df842c36-41f7-4606-b219-7879cf1c4825
fi
echo 'Loading Linux linux ...'
linux /boot/vmlinuz-linux root=UUID=df842c36-41f7-4606-b219-7879cf1c4825 rw quiet systemd.show_status=0
echo 'Loading initial ramdisk ...'
initrd /boot/initramfs-linux-fallback.img
### END /etc/grub.d/10_linux ###
### BEGIN /etc/grub.d/20_linux_xen ###
### END /etc/grub.d/20_linux_xen ###
### BEGIN /etc/grub.d/30_os-prober ###
### END /etc/grub.d/30_os-prober ###
### BEGIN /etc/grub.d/40_custom ###
# This file provides an easy way to add custom menu entries. Simply type the
# menu entries you want to add after this comment. Be careful not to change
# the 'exec tail' line above.
### END /etc/grub.d/40_custom ###
### BEGIN /etc/grub.d/41_custom ###
if [ -f ${config_directory}/custom.cfg ]; then
source ${config_directory}/custom.cfg
elif [ -z "${config_directory}" -a -f $prefix/custom.cfg ]; then
source $prefix/custom.cfg;
fi
### END /etc/grub.d/41_custom ###
### BEGIN /etc/grub.d/60_memtest86+ ###
### END /etc/grub.d/60_memtest86+ ###
and fstab:
% cat /etc/fstab ~
# /etc/fstab: static file system information
# <file system> <dir> <type> <options> <dump> <pass>
# /dev/sda4
UUID=df842c36-41f7-4606-b219-7879cf1c4825 / ext4 rw,relatime,data=ordered 0 1
# /dev/sda5
UUID=0a37147c-f87b-4c2c-9b2d-75c852568c4b /home ext4 rw,relatime,data=ordered 0 2
Found a few things about 30 things on the net, this,  but by my reckoning, it is not similar enough / I don't understand the solution enough to be comfortable applying it to my set up.   Tried that, it didn't work.  Seems like every issue that manifests itself in this way (esp in dual boot situations) has a different solution, ranging from blacklisting certain modules  in /etc/default/grub to reording the block and autodetect hooks in mkinitcpio.conf.
Any help troubleshooting this would be greatly appreciated.
Also, here is mkinitcpio.conf (sans comments):
# vim:set ft=sh
# MODULES
MODULES=""
# BINARIES
BINARIES=""
# FILES
FILES=""
# HOOKS
HOOKS="base udev block autodetect modconf filesystems keyboard fsck usbinput"
Last edited by oktorok (2014-11-04 02:29:08)

Answer 1

Is the root filesystem encrypted by default?   I would like to try a solution like adding
cryptdevice=device:dmname
to my /etc/default/grub but I don't know what to put for dmname.  It seems like the wiki suggests stating it verbatum,
dmname is the device-mapper name given to the device after decryption, which will be available as /dev/mapper/dmname.
I tried
GRUB_CMDLINE_LINUX="cryptdevice=/dev/sda4:/dev/mapper/dmname"
without success.  This solution doesn't make sense if the filesystem is not encrypted. 
I don't really think this applies, but I can't understand why the modules.devname would not be found when it plainly exists exactly where the system is looking for it.
In the meantime I'm trying
sudo mkinitcpio -k 3.14.17-1-lts -g /boot/initramfs-linux-lts.img -S autodetect
to set up the initial ram env, per this thread.
[update] the above method, referenced in the link, did not fix the issue.
Last edited by oktorok (2014-08-28 22:24:43)