On 12/5/2013 3:08 PM, John Hupp wrote:
On 12/5/2013 11:31 AM, John Hupp wrote:
I'm still troubleshooting the problem in which (on *buntu 13.10) client
boot fails after the splash screen with 'Error: socket failed:
connection refused.'
My current working premise is that this is an nbd error.
So I want to see the nbd-client command line and configuration in the
client initramfs. I'm assuming that loads from the initramfs /init
script, but 'cat /init' produces rather useless scrolls-by-in-a-flash
output, and the initramfs does not support 'cat /init | less.'
Can I locate the init script somewhere on the server?
I found out that I can view the init script from /boot/initrd.img-* via
a procedure like:
$ mkdir -p /tmp/initrd
$ cd /tmp/initrd
$ cp /boot/initrd.img-<rest of your filename> ./initrd.gz
$ gzip -d initrd.gz
$ cpio -i < initrd
After that the contents of the initrd are going to be unpacked into the
/tmp/initrd directory.
But that is not the same initrd used on the LTSP client, is it? If so,
there is no mention of nbd anywhere in its init script.
After thinking about it overnight, I realized that the server syslog
would tell me where the initrd is. It is at /var/lib/tftpboot/ltsp/<arch>.
And in a slightly simplified procedure, I simply copied the initrd
archive from there to /tmp and there ran (to unpack it):
$ zcat initrd.img-3.11.0-12-generic | cpio -div
But it is not so simple from there. I found that /init does not launch
nbd-client directly but via other scripts. The relevant ones seem to be:
/scripts/local-top/nbd
/scripts/local-top/nbd-ltsp
/sbin/nbd-client-proxy
Even knowing this much now, my script knowledge is poor, so I haven't
yet been able to parse exactly what nbd-client command is being run.
Can anyone decipher this? I attach the scripts.
I also thought about just trying to run an nbd-client command directly
from the busybox shell to see if it produces the same error as
originally reported. But the nbd-client-proxy comments seem to indicate
that this won't work. Perhaps someone can say more about that.
#!/bin/sh
[ -d /dev ] || mkdir -m 0755 /dev
[ -d /root ] || mkdir -m 0700 /root
[ -d /sys ] || mkdir /sys
[ -d /proc ] || mkdir /proc
[ -d /tmp ] || mkdir /tmp
mkdir -p /var/lock
mount -t sysfs -o nodev,noexec,nosuid sysfs /sys
mount -t proc -o nodev,noexec,nosuid proc /proc
# Some things don't work properly without /etc/mtab.
ln -sf /proc/mounts /etc/mtab
grep -q '\<quiet\>' /proc/cmdline || echo "Loading, please wait..."
# Note that this only becomes /dev on the real filesystem if udev's scripts
# are used; which they will be, but it's worth pointing out
if ! mount -t devtmpfs -o mode=0755 udev /dev; then
echo "W: devtmpfs not available, falling back to tmpfs for /dev"
mount -t tmpfs -o mode=0755 udev /dev
[ -e /dev/console ] || mknod -m 0600 /dev/console c 5 1
[ -e /dev/null ] || mknod /dev/null c 1 3
fi
mkdir /dev/pts
mount -t devpts -o noexec,nosuid,gid=5,mode=0620 devpts /dev/pts || true
mount -t tmpfs -o "noexec,nosuid,size=10%,mode=0755" tmpfs /run
mkdir /run/initramfs
# compatibility symlink for the pre-oneiric locations
ln -s /run/initramfs /dev/.initramfs
# Export the dpkg architecture
export DPKG_ARCH=
. /conf/arch.conf
# Set modprobe env
export MODPROBE_OPTIONS="-qb"
# Export relevant variables
export ROOT=
export ROOTDELAY=
export ROOTFLAGS=
export ROOTFSTYPE=
export IP=
export BOOT=
export BOOTIF=
export UBIMTD=
export break=
export init=/sbin/init
export quiet=n
export readonly=y
export rootmnt=/root
export debug=
export panic=
export blacklist=
export resume=
export resume_offset=
export recovery=
# mdadm needs hostname to be set. This has to be done before the udev rules are
called!
if [ -f "/etc/hostname" ]; then
/bin/hostname -b -F /etc/hostname 2>&1 1>/dev/null
fi
# Bring in the main config
. /conf/initramfs.conf
for conf in conf/conf.d/*; do
[ -f ${conf} ] && . ${conf}
done
. /scripts/functions
# Parse command line options
for x in $(cat /proc/cmdline); do
case $x in
init=*)
init=${x#init=}
;;
root=*)
ROOT=${x#root=}
case $ROOT in
LABEL=*)
ROOT="${ROOT#LABEL=}"
# support any / in LABEL= path (escape to \x2f)
case "${ROOT}" in
*/*)
if command -v sed >/dev/null 2>&1; then
ROOT="$(echo ${ROOT} | sed 's,/,\\x2f,g')"
else
if [ "${ROOT}" != "${ROOT#/}" ]; then
ROOT="\x2f${ROOT#/}"
fi
if [ "${ROOT}" != "${ROOT%/}" ]; then
ROOT="${ROOT%/}\x2f"
fi
IFS='/'
newroot=
for s in $ROOT; do
newroot="${newroot:+${newroot}\\x2f}${s}"
done
unset IFS
ROOT="${newroot}"
fi
esac
ROOT="/dev/disk/by-label/${ROOT}"
;;
UUID=*)
ROOT="/dev/disk/by-uuid/${ROOT#UUID=}"
;;
/dev/nfs)
[ -z "${BOOT}" ] && BOOT=nfs
;;
esac
;;
rootflags=*)
ROOTFLAGS="-o ${x#rootflags=}"
;;
rootfstype=*)
ROOTFSTYPE="${x#rootfstype=}"
;;
rootdelay=*)
ROOTDELAY="${x#rootdelay=}"
case ${ROOTDELAY} in
*[![:digit:].]*)
ROOTDELAY=
;;
esac
;;
resumedelay=*)
RESUMEDELAY="${x#resumedelay=}"
;;
loop=*)
LOOP="${x#loop=}"
;;
loopflags=*)
LOOPFLAGS="-o ${x#loopflags=}"
;;
loopfstype=*)
LOOPFSTYPE="${x#loopfstype=}"
;;
cryptopts=*)
cryptopts="${x#cryptopts=}"
;;
nfsroot=*)
NFSROOT="${x#nfsroot=}"
;;
netboot=*)
NETBOOT="${x#netboot=}"
;;
ip=*)
IP="${x#ip=}"
;;
boot=*)
BOOT=${x#boot=}
;;
ubi.mtd=*)
UBIMTD=${x#ubi.mtd=}
;;
resume=*)
RESUME="${x#resume=}"
;;
resume_offset=*)
resume_offset="${x#resume_offset=}"
;;
noresume)
noresume=y
;;
panic=*)
panic="${x#panic=}"
case ${panic} in
*[![:digit:].]*)
panic=
;;
esac
;;
quiet)
quiet=y
;;
ro)
readonly=y
;;
rw)
readonly=n
;;
debug)
debug=y
quiet=n
exec >/run/initramfs/initramfs.debug 2>&1
set -x
;;
debug=*)
debug=y
quiet=n
set -x
;;
break=*)
break=${x#break=}
;;
break)
break=premount
;;
blacklist=*)
blacklist=${x#blacklist=}
;;
netconsole=*)
netconsole=${x#netconsole=}
;;
BOOTIF=*)
BOOTIF=${x#BOOTIF=}
;;
hwaddr=*)
BOOTIF=${x#BOOTIF=}
;;
recovery)
recovery=y
;;
esac
done
if [ -n "${noresume}" ]; then
export noresume
unset resume
else
resume=${RESUME:-}
fi
maybe_break top
# export BOOT variable value for compcache,
# so we know if we run from casper
export BOOT
# Don't do log messages here to avoid confusing graphical boots
run_scripts /scripts/init-top
maybe_break modules
[ "$quiet" != "y" ] && log_begin_msg "Loading essential drivers"
load_modules
[ "$quiet" != "y" ] && log_end_msg
[ -n "${netconsole}" ] && modprobe netconsole netconsole="${netconsole}"
maybe_break premount
[ "$quiet" != "y" ] && log_begin_msg "Running /scripts/init-premount"
run_scripts /scripts/init-premount
[ "$quiet" != "y" ] && log_end_msg
maybe_break mount
log_begin_msg "Mounting root file system"
. /scripts/${BOOT}
parse_numeric ${ROOT}
maybe_break mountroot
mountroot
log_end_msg
maybe_break bottom
[ "$quiet" != "y" ] && log_begin_msg "Running /scripts/init-bottom"
run_scripts /scripts/init-bottom
[ "$quiet" != "y" ] && log_end_msg
# Preserve information on old systems without /run on the rootfs
if [ -d ${rootmnt}/run ]; then
mount -n -o move /run ${rootmnt}/run
else
# The initramfs udev database must be migrated:
if [ -d /run/udev ] && [ ! -d /dev/.udev ]; then
mv /run/udev /dev/.udev
fi
# The initramfs debug info must be migrated:
if [ -d /run/initramfs ] && [ ! -d /dev/.initramfs ]; then
mv /run/initramfs /dev/.initramfs
fi
umount /run
fi
# Move virtual filesystems over to the real filesystem
mount -n -o move /sys ${rootmnt}/sys
mount -n -o move /proc ${rootmnt}/proc
validate_init() {
checktarget="${1}"
# Work around absolute symlinks
if [ -d "${rootmnt}" ] && [ -h "${rootmnt}${checktarget}" ]; then
case $(readlink "${rootmnt}${checktarget}") in /*)
checktarget="$(chroot ${rootmnt} readlink
${checktarget})"
;;
esac
fi
# Make sure the specified init can be executed
if [ ! -x "${rootmnt}${checktarget}" ]; then
return 1
fi
# Upstart uses /etc/init as configuration directory :-/
if [ -d "${rootmnt}${checktarget}" ]; then
return 1
fi
}
# Check init bootarg
if [ -n "${init}" ]; then
if ! validate_init "$init"; then
echo "Target filesystem doesn't have requested ${init}."
init=
fi
fi
# Common case: /sbin/init is present
if [ ! -x "${rootmnt}/sbin/init" ]; then
# ... if it's not available search for valid init
if [ -z "${init}" ] ; then
for inittest in /sbin/init /etc/init /bin/init /bin/sh; do
if validate_init "${inittest}"; then
init="$inittest"
break
fi
done
fi
# No init on rootmount
if ! validate_init "${init}" ; then
panic "No init found. Try passing init= bootarg."
fi
fi
maybe_break init
# don't leak too much of env - some init(8) don't clear it
# (keep init, rootmnt)
unset debug
unset MODPROBE_OPTIONS
unset DPKG_ARCH
unset ROOTFLAGS
unset ROOTFSTYPE
unset ROOTDELAY
unset ROOT
unset IP
unset BOOT
unset BOOTIF
unset UBIMTD
unset blacklist
unset break
unset noresume
unset panic
unset quiet
unset readonly
unset resume
unset resume_offset
# Chain to real filesystem
exec run-init ${rootmnt} ${init} "$@" ${recovery:+--startup-event=recovery}
<${rootmnt}/dev/console >${rootmnt}/dev/console 2>&1
panic "Could not execute run-init."
#!/bin/sh
# We don't have any prerequisites
case $1 in
prereqs)
exit 0
;;
esac
for x in $(cat /proc/cmdline); do
case "$x" in
nbddev=*)
nbddev="${x#nbddev=}"
;;
nbdroot=*)
nbdroot="${x#nbdroot=}"
;;
root=/dev/nbd*)
nbddev="${x#root=}"
;;
esac
done
# if nbd root is not requested exit early and silently
if [ -z "$nbdroot" ] && [ -z "$nbddev" ]
then
exit 0
fi
. /scripts/functions
log_begin_msg "Setting up nbd-client"
configure_networking
# Support setting stuff using DHCP by overloading 'option root-path'
case "$nbdroot" in
''|dhcp)
nbdroot=$ROOTPATH
;;
esac
nbdrootdev="$nbddev"
nbdbasedev="${nbddev#/dev/}"
case "$nbdroot" in
*,*,*)
nbdsrv="${nbdroot%%,*}"
nbdport="${nbdroot%,*}"
nbdport="${nbdport##*,}"
# root= parameter overrides three-option nbdroot= parameter
if [ -z "$nbdrootdev" ]
then
nbdbasedev="${nbdroot##*,}"
nbdrootdev=/dev/$nbdbasedev
fi
;;
*,*)
nbdsrv="${nbdroot%,*}"
nbdport="${nbdroot#*,}"
;;
\[*\]*)
# [ipv6]:port/path
nbdsrv=${nbdroot%\]*}
nbdsrv=${nbdsrv#\[}
nbdportpath=${nbdroot#\[$nbdsrv\]}
nbdportpath=${nbdportpath#:}
nbdport=${nbdportpath%%/*}
nbdpath=${nbdportpath#$nbdport}
;;
*)
# ipv4:port/path
nbdsrv=${nbdroot%%[:/]*}
nbdportpath=${nbdroot#$nbdsrv}
nbdportpath=${nbdportpath#:}
nbdport=${nbdportpath%%/*}
nbdpath=${nbdportpath#$nbdport}
;;
esac
case "$nbdport" in
*[^0-9]*)
# non-numeric characters, assume a name rather than a port
nbdpath="$nbdport"
unset nbdport
;;
esac
nbdrootdev=${nbdrootdev%p*}
nbdbasedev=${nbdbasedev%p*}
# If host is omitted, use ROOTSERVER from DHCP.
case "$nbdsrv" in
''|dhcp)
nbdsrv=$ROOTSERVER
;;
esac
if [ -z "$nbdsrv" ] || [ -z "$nbdrootdev" ] || ( [ -z "$nbdpath" ] && [ -z
"$nbdport" ] )
then
log_failure_msg "Insufficient information to set up nbd, quitting
(nbdroot=$nbdroot, host=$nbdsrv, name=$nbdpath, port=$nbdport,
nbd-device=$nbdrootdev)"
exit 0
fi
# Support defining an alternate launch script with env variable NBDCLIENT.
NBDCLIENT=${NBDCLIENT:-/sbin/nbd-client}
$NBDCLIENT $nbdsrv ${nbdpath:+-N} $nbdpath $nbdport $nbdrootdev -swap -persist
# This should be removed once the cfq scheduler no longer deadlocks nbd
# devices
if grep -q '\[cfq\]' /sys/block/$nbdbasedev/queue/scheduler
then
echo deadline > /sys/block/$nbdbasedev/queue/scheduler
fi
#!/bin/sh
# Work around LP bug #696435
if [ "$ROOT" = /dev/nbd0 ] && [ -z "$FSTYPE" ]; then
FSTYPE=$(blkid -s TYPE -o value "${ROOT}")
if [ -n "$FSTYPE" ]; then
echo "FSTYPE='$FSTYPE'" > /conf/param.conf
fi
fi
#!/bin/sh
# This is just a wrapper script that accepts the same parameters as nbd-client,
# and launches nbd-proxy to connect to the specified server,
# and nbd-client to connect to the nbd-proxy in localhost.
# Maybe at some point nbd-proxy itself can accept that syntax, so the wrapper
# won't be needed anymore.
# It might be ran from the initramfs, so only busybox utilities should be used.
if [ $# -eq 0 ]; then
echo "Usage: $0 host port nbd_device [-block-size|-b block size]
[-timeout|-t timeout] [-swap|-s] [-sdp|-S] [-persist|-p] [-nofork|-n]
For more info, see the nbd-client man page." >&2
exit 1
fi
# Make sure the loopback interface has an address for nbd-proxy
ip addr add dev lo 127.0.0.1
ip link set lo up
# To make the initramfs nbd script call nbd-client-proxy instead of nbd-client,
# specify NBDCLIENT=nbd-client-proxy in the kernel command line.
# Then the local-top/nbd initramfs script will call nbd-client-proxy this way:
# $NBDCLIENT $nbdsrv ${nbdpath:+-N} $nbdpath $nbdport $nbdrootdev -swap -persist
host="$1"
if [ "$2" = "-N" ]; then
port=10809
else
port="$2"
fi
nbd-proxy "$host" "$port" "$port"
# Remove the host parameter and chain to nbd-client with the rest of the command
# line.
shift
exec nbd-client 127.0.0.1 "$@"
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