Arch Linux

kasu

Member

Registered: 2013-06-23

Posts: 8

[SOLVED] Unable to find root device ''

I am getting this error message after fresh installs of Arch.  I have followed the beginner's guide exactly, repeated the steps at least 5 times now, checking mkinitcpio.conf and even skipping that step altogether, repartitioning, naming partitions, and making sure I typed everything correctly.  What could be the problem?

:: running early hook [udev]
:: running hook [udev]
:: Triggering uevents...
ERROR: device '' not found. Skipping fsck.
ERROR: Unable to find root device ''.
You are being dropped to a recovery shell
    Type 'exit' to try and continue botting
sh: can't access tty; job control turned off

I am installing on a UEFI laptop that won't let me boot the installation media in UEFI mode, so I am installing in legacy mode, skipping the bootloader configuration, then using the EFI shell and rEFInd to boot in UEFI mode.  sda1 is ESP, sda2 is root, sda3 is swap, and sda4 is home.  My first attempt at an install made it past this point but dropped me into emergency mode, so I decided to reinstall.  I have copied the files for EFI shell and rEFInd onto the ESP, and rEFInd shows a generic penguin logo for these installs, whereas it showed an Arch logo previously.  Now that I think about it, the working Arch installation was showing that it was installed on the root partition, whereas it is now showing as installed on the ESP.

Last edited by kasu (2013-06-24 03:40:18)

kasu

Member

Registered: 2013-06-23

Posts: 8

Re: [SOLVED] Unable to find root device ''

Post fstab and whatever you are using to boot. If that's a command line in the shell, post that. If it is an efi boot menu entry, post that. If it is refind, post refind.conf and refind_linux.conf. Also ls -R  <path to your ESP>.

fstab

# 
# /etc/fstab: static file system information
#
# <file system>	<dir>	<type>	<options>	<dump>	<pass>
# /dev/sda2
UUID=fbdeb4af-2149-42d8-835b-a0ca6ef0586e	/         	ext4      	rw,relatime,data=ordered	0 1

# /dev/sda4
UUID=9f40af1d-eaa1-4787-8723-b7d720734f96	/home     	ext4      	rw,relatime,data=ordered	0 2

# /dev/sda1
UUID=7DD5-7841      	/boot     	vfat      	rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro	0 2

# /dev/sda3
UUID=b6eda7ee-a570-42cb-bae5-8ee4e3432358	none      	swap      	defaults  	0 0

rEFInd boot entry

initrd=\initramfs-linux.img

refind.conf

#
# refind.conf
# Configuration file for the rEFInd boot menu
#

# Timeout in seconds for the main menu screen. Setting the timeout to 0
# disables automatic booting (i.e., no timeout).
#
timeout 20

# Screen saver timeout; the screen blanks after the specified number of
# seconds with no keyboard input. The screen returns after most keypresses
# (unfortunately, not including modifier keys such as Shift, Control, Alt,
# or Option). The default is 0, which disables the screen saver.
#screensaver 300

# Hide user interface elements for personal preference or to increase
# security:
#  banner      - the rEFInd title banner (built-in or loaded via "banner")
#  label       - boot option text label in the menu
#  singleuser  - remove the submenu options to boot Mac OS X in single-user
#                or verbose modes; affects ONLY MacOS X
#  safemode    - remove the submenu option to boot Mac OS X in "safe mode"
#  hwtest      - the submenu option to run Apple's hardware test
#  arrows      - scroll arrows on the OS selection tag line
#  hints       - brief command summary in the menu
#  editor      - the options editor (+, F2, or Insert on boot options menu)
#  all         - all of the above
# Default is none of these (all elements active)
#
#hideui singleuser
#hideui all

# Set the name of a subdirectory in which icons are stored. Icons must
# have the same names they have in the standard directory. The directory
# name is specified relative to the main rEFInd binary's directory. If
# an icon can't be found in the specified directory, an attempt is made
# to load it from the default directory; thus, you can replace just some
# icons in your own directory and rely on the default for others.
# Default is "icons".
#
#icons_dir myicons

# Use a custom title banner instead of the rEFInd icon and name. The file
# path is relative to the directory where refind.efi is located. The color
# in the top left corner of the image is used as the background color
# for the menu screens. Currently uncompressed BMP images with color
# depths of 24, 8, 4 or 1 bits are supported, as well as PNG images.
#
#banner hostname.bmp
#banner mybanner.png

# Custom images for the selection background. There is a big one (144 x 144)
# for the OS icons, and a small one (64 x 64) for the function icons in the
# second row. If only a small image is given, that one is also used for
# the big icons by stretching it in the middle. If only a big one is given,
# the built-in default will be used for the small icons.
#
# Like the banner option above, these options take a filename of an
# uncompressed BMP image file with a color depth of 24, 8, 4, or 1 bits,
# or a PNG image. The PNG format is required if you need transparency
# support (to let you "see through" to a full-screen banner).
#
#selection_big   selection-big.bmp
#selection_small selection-small.bmp

# Set the font to be used for all textual displays in graphics mode.
# The font must be a PNG file with alpha channel transparency. It must
# contain ASCII characters 32-126 (space through tilde), inclusive, plus
# a glyph to be displayed in place of characters outside of this range,
# for a total of 96 glyphs. Only monospaced fonts are supported. Fonts
# may be of any size, although large fonts can produce display
# irregularities.
# The default is rEFInd's built-in font, Luxi Mono Regular 12 point.
#
#font myfont.png

# Use text mode only. When enabled, this option forces rEFInd into text mode.
# Passing this option a "0" value causes graphics mode to be used. Pasing
# it no value or any non-0 value causes text mode to be used.
# Default is to use graphics mode.
#
#textonly

# Set the EFI text mode to be used for textual displays. This option
# takes a single digit that refers to a mode number. Mode 0 is normally
# 80x25, 1 is sometimes 80x50, and higher numbers are system-specific
# modes. Mode 1024 is a special code that tells rEFInd to not set the
# text mode; it uses whatever was in use when the program was launched.
# If you specify an invalid mode, rEFInd pauses during boot to inform
# you of valid modes.
# CAUTION: On VirtualBox, and perhaps on some real computers, specifying
# a text mode and uncommenting the "textonly" option while NOT specifying
# a resolution can result in an unusable display in the booted OS.
# Default is 1024 (no change)
#
#textmode 2

# Set the screen's video resolution. Pass this option either:
#  * two values, corresponding to the X and Y resolutions
#  * one value, corresponding to a GOP (UEFI) video mode
# Note that not all resolutions are supported. On UEFI systems, passing
# an incorrect value results in a message being shown on the screen to
# that effect, along with a list of supported modes. On EFI 1.x systems
# (e.g., Macintoshes), setting an incorrect mode silently fails. On both
# types of systems, setting an incorrect resolution results in the default
# resolution being used. A resolution of 1024x768 usually works, but higher
# values often don't.
# Default is "0 0" (use the system default resolution, usually 800x600).
#
#resolution 1024 768
#resolution 3

# Launch specified OSes in graphics mode. By default, rEFInd switches
# to text mode and displays basic pre-launch information when launching
# all OSes except OS X. Using graphics mode can produce a more seamless
# transition, but displays no information, which can make matters
# difficult if you must debug a problem. Also, on at least one known
# computer, using graphics mode prevents a crash when using the Linux
# kernel's EFI stub loader. You can specify an empty list to boot all
# OSes in text mode.
# Valid options:
#   osx     - Mac OS X
#   linux   - A Linux kernel with EFI stub loader
#   elilo   - The ELILO boot loader
#   grub    - The GRUB (Legacy or 2) boot loader
#   windows - Microsoft Windows
# Default value: osx
#
#use_graphics_for osx,linux

# Which non-bootloader tools to show on the tools line, and in what
# order to display them:
#  shell           - the EFI shell (requires external program; see rEFInd
#                    documentation for details)
#  gptsync         - the (dangerous) gptsync.efi utility (requires external
#                    program; see rEFInd documentation for details)
#  apple_recovery  - boots the Apple Recovery HD partition, if present
#  mok_tool        - makes available the Machine Owner Key (MOK) maintenance
#                    tool, MokManager.efi, used on Secure Boot systems
#  about           - an "about this program" option
#  exit            - a tag to exit from rEFInd
#  shutdown        - shuts down the computer (a bug causes this to reboot
#                    EFI systems)
#  reboot          - a tag to reboot the computer
#  firmware        - a tag to reboot the computer into the firmware's
#                    user interface (ignored on older computers)
# Default is shell,apple_recovery,mok_tool,about,shutdown,reboot,firmware
#
#showtools shell, mok_tool, about, reboot, exit, firmware

# Directories in which to search for EFI drivers. These drivers can
# provide filesystem support, give access to hard disks on plug-in
# controllers, etc. In most cases none are needed, but if you add
# EFI drivers and you want rEFInd to automatically load them, you
# should specify one or more paths here. rEFInd always scans the
# "drivers" and "drivers_{arch}" subdirectories of its own installation
# directory (where "{arch}" is your architecture code); this option
# specifies ADDITIONAL directories to scan.
# Default is to scan no additional directories for EFI drivers
#
#scan_driver_dirs EFI/tools/drivers,drivers

# Which types of boot loaders to search, and in what order to display them:
#  internal      - internal EFI disk-based boot loaders
#  external      - external EFI disk-based boot loaders
#  optical       - EFI optical discs (CD, DVD, etc.)
#  hdbios        - BIOS disk-based boot loaders
#  biosexternal  - BIOS external boot loaders (USB, eSATA, etc.)
#  cd            - BIOS optical-disc boot loaders
#  manual        - use stanzas later in this configuration file
# Note that the legacy BIOS options require firmware support, which is
# not present on all computers.
# On UEFI PCs, default is internal,external,optical,manual
# On Macs, default is internal,hdbios,external,biosexternal,optical,cd,manual
#
#scanfor internal,external,optical,manual

# Delay for the specified number of seconds before scanning disks.
# This can help some users who find that some of their disks
# (usually external or optical discs) aren't detected initially,
# but are detected after pressing Esc.
# The default is 0.
#
#scan_delay 5

# When scanning volumes for EFI boot loaders, rEFInd always looks for
# Mac OS X's and Microsoft Windows' boot loaders in their normal locations,
# and scans the root directory and every subdirectory of the /EFI directory
# for additional boot loaders, but it doesn't recurse into these directories.
# The also_scan_dirs token adds more directories to the scan list.
# Directories are specified relative to the volume's root directory. This
# option applies to ALL the volumes that rEFInd scans UNLESS you include
# a volume name and colon before the directory name, as in "myvol:/somedir"
# to scan the somedir directory only on the filesystem named myvol. If a
# specified directory doesn't exist, it's ignored (no error condition
# results). The default is to scan the "boot" directory in addition to
# various hard-coded directories.
#
#also_scan_dirs boot,ESP2:EFI/linux/kernels

# Partitions to omit from scans. You must specify a volume by its
# label, which you can obtain in an EFI shell by typing "vol", from
# Linux by typing "blkid /dev/{devicename}", or by examining the
# disk's label in various OSes' file browsers.
# The default is "Recovery HD".
#
#dont_scan_volumes "Recovery HD"

# Directories that should NOT be scanned for boot loaders. By default,
# rEFInd doesn't scan its own directory or the EFI/tools directory.
# You can "blacklist" additional directories with this option, which
# takes a list of directory names as options. You might do this to
# keep EFI/boot/bootx64.efi out of the menu if that's a duplicate of
# another boot loader or to exclude a directory that holds drivers
# or non-bootloader utilities provided by a hardware manufacturer. If
# a directory is listed both here and in also_scan_dirs, dont_scan_dirs
# takes precedence. Note that this blacklist applies to ALL the
# filesystems that rEFInd scans, not just the ESP, unless you precede
# the directory name by a filesystem name, as in "myvol:EFI/somedir"
# to exclude EFI/somedir from the scan on the myvol volume but not on
# other volumes.
#
#dont_scan_dirs ESP:/EFI/boot,EFI/Dell

# Files that should NOT be included as EFI boot loaders (on the
# first line of the display). If you're using a boot loader that
# relies on support programs or drivers that are installed alongside
# the main binary or if you want to "blacklist" certain loaders by
# name rather than location, use this option. Note that this will
# NOT prevent certain binaries from showing up in the second-row
# set of tools. Most notably, MokManager.efi is in this blacklist,
# but will show up as a tool if present in certain directories. You
# can control the tools row with the showtools token.
# The default is shim.efi,TextMode.efi,ebounce.efi,GraphicsConsole.efi,MokManager.efi,HashTool.efi,HashTool-signed.efi
#
#dont_scan_files shim.efi,MokManager.efi

# Scan for Linux kernels that lack a ".efi" filename extension. This is
# useful for better integration with Linux distributions that provide
# kernels with EFI stub loaders but that don't give those kernels filenames
# that end in ".efi", particularly if the kernels are stored on a
# filesystem that the EFI can read. When uncommented, this option causes
# all files in scanned directories with names that begin with "vmlinuz"
# or "bzImage" to be included as loaders, even if they lack ".efi"
# extensions. The drawback to this option is that it can pick up kernels
# that lack EFI stub loader support and other files. Passing this option
# a "0" value causes kernels without ".efi" extensions to NOT be scanned;
# passing it alone or with any other value causes all kernels to be scanned.
# Default is to NOT scan for kernels without ".efi" extensions.
#
scan_all_linux_kernels

# Set the maximum number of tags that can be displayed on the screen at
# any time. If more loaders are discovered than this value, rEFInd shows
# a subset in a scrolling list. If this value is set too high for the
# screen to handle, it's reduced to the value that the screen can manage.
# If this value is set to 0 (the default), it's adjusted to the number
# that the screen can handle.
#
#max_tags 0

# Set the default menu selection.  The available arguments match the
# keyboard accelerators available within rEFInd.  You may select the
# default loader using:
#  - A digit between 1 and 9, in which case the Nth loader in the menu
#    will be the default. 
#  - Any substring that corresponds to a portion of the loader's title
#    (usually the OS's name or boot loader's path).
#
#default_selection 1

# Include a secondary configuration file within this one. This secondary
# file is loaded as if its options appeared at the point of the "include"
# token itself, so if you want to override a setting in the main file,
# the secondary file must be referenced AFTER the setting you want to
# override. Note that the secondary file may NOT load a tertiary file.
#
#include manual.conf

# Sample manual configuration stanzas. Each begins with the "menuentry"
# keyword followed by a name that's to appear in the menu (use quotes
# if you want the name to contain a space) and an open curly brace
# ("{"). Each entry ends with a close curly brace ("}"). Common
# keywords within each stanza include:
#
#  volume    - identifies the filesystem from which subsequent files
#              are loaded. You can specify the volume by label or by
#              a number followed by a colon (as in "0:" for the first
#              filesystem or "1:" for the second).
#  loader    - identifies the boot loader file
#  initrd    - Specifies an initial RAM disk file
#  icon      - specifies a custom boot loader icon
#  ostype    - OS type code to determine boot options available by
#              pressing Insert. Valid values are "MacOS", "Linux",
#              "Windows", and "XOM". Case-sensitive.
#  graphics  - set to "on" to enable graphics-mode boot (useful
#              mainly for MacOS) or "off" for text-mode boot.
#              Default is auto-detected from loader filename.
#  options   - sets options to be passed to the boot loader; use
#              quotes if more than one option should be passed or
#              if any options use characters that might be changed
#              by rEFInd parsing procedures (=, /, #, or tab).
#  disabled  - use alone or set to "yes" to disable this entry.
#
# Note that you can use either DOS/Windows/EFI-style backslashes (\)
# or Unix-style forward slashes (/) as directory separators. Either
# way, all file references are on the ESP from which rEFInd was
# launched.
# Use of quotes around parameters causes them to be interpreted as
# one keyword, and for parsing of special characters (spaces, =, /,
# and #) to be disabled. This is useful mainly with the "options"
# keyword. Use of quotes around parameters that specify filenames is
# permissible, but you must then use backslashes instead of slashes,
# except when you must pass a forward slash to the loader, as when
# passing a root= option to a Linux kernel.

# Below are several sample boot stanzas. All are disabled by default.
# Find one similar to what you need, copy it, remove the "disabled" line,
# and adjust the entries to suit your needs.

# A sample entry for a Linux 3.3 kernel with its new EFI boot stub
# support on a filesystem called "KERNELS". This entry includes
# Linux-specific boot options and specification of an initial RAM disk.
# Note uses of Linux-style forward slashes, even in the initrd
# specification. Also note that a leading slash is optional in file
# specifications.
menuentry Linux {
	icon EFI/refind/icons/os_linux.icns
	volume KERNELS
	loader bzImage-3.3.0-rc7
	initrd initrd-3.3.0.img
	options "ro root=UUID=5f96cafa-e0a7-4057-b18f-fa709db5b837"
	disabled
}

# A sample entry for loading Ubuntu using its standard name for
# its GRUB 2 boot loader. Note uses of Linux-style forward slashes
menuentry Ubuntu {
	loader /EFI/ubuntu/grubx64.efi
	icon /EFI/refined/icons/os_linux.icns
	disabled
}

# A minimal ELILO entry, which probably offers nothing that
# auto-detection can't accomplish.
menuentry "ELILO" {
	loader \EFI\elilo\elilo.efi
	disabled
}

# Like the ELILO entry, this one offers nothing that auto-detection
# can't do; but you might use it if you want to disable auto-detection
# but still boot Windows....
menuentry "Windows 7" {
	loader \EFI\Microsoft\Boot\bootmgfw.efi
	disabled
}

# EFI shells are programs just like boot loaders, and can be
# launched in the same way. You can pass a shell the name of a
# script that it's to run on the "options" line. The script
# could initialize hardware and then launch an OS, or it could
# do something entirely different.
menuentry "Windows via shell script" {
	icon \EFI\refind\icons\os_win.icns
	loader \EFI\tools\shell.efi
	options "fs0:\EFI\tools\launch_windows.nsh"
	disabled
}

# Mac OS is normally detected and run automatically; however,
# if you want to do something unusual, a manual boot stanza may
# be the way to do it. This one does nothing very unusual, but
# it may serve as a starting point. Note that you'll almost
# certainly need to change the "volume" line for this example
# to work.
menuentry "My Mac OS X" {
	icon \EFI\refind\icons\os_mac.icns
	volume "OS X boot"
	loader \System\Library\CoreServices\boot.efi
	disabled
}

refind_linux.conf

Doesn't exist

ls -r /boot

/boot:
initramfs-linux-fallback.img  initramfs-linux.img  refind  shellx64_v2.efi  vmlinuz-linux

/boot/refind:
drivers  icons  refind.conf  refind_x64.efi

/boot/refind/drivers:
...

/bot/refind/icons:
...

kasu

Member

Registered: 2013-06-23

Posts: 8

Re: [SOLVED] Unable to find root device ''

I solved the problem.  I changed the rEFInd boot entry to this:

ro root=/dev/sda2 initrd=\initramfs-linux.img

Thanks!