[debian-knoppix] Persistent /etc
Hi all,
I was trying to use a hard disk partition for /etc, so that on a
machine the settings remain same for knoppix even after reboot. Today I
have succeeded in that. I hacked the linuxrc a bit so that /etc is
loaded mounted initially and the files are not deleted after creating
symlinks.
I am attaching my modified linuxrc and comment the relevant portions
here. I do not have a unmodified linuxrc right now for a diff :(
Just after loadmodules() I have mounted /etc from a hard disk.
------------------
done
test -n "$INTERACTIVE" && echo "0" > /proc/sys/kernel/printk
echo -n "${CRE}"
}
# Mount the /etc from hard disk
echo ${RED} Mounting etc from hard disk ${NORMAL}
mount -t ext2 /dev/hda6 /etc
# Check for SCSI, use modules on bootfloppy first
if test -n "$INTERACTIVE"; then
-------------------
After creating symlinks in /etc, I commented out the deleting part and
made sure that copying do not overwrite the files already present.
---------------------
# Create links from CDROM for UNWRITABLE (remaining) files
cp -aus /KNOPPIX/var/* /var/ 2>/dev/null
cp -aus /KNOPPIX/etc/* /etc/ 2>/dev/null
# Make SURE that these are files, not links!
#rm -rf /etc/ftpusers /etc/passwd /etc/shadow /etc/group \
# /etc/ppp /etc/isdn /etc/ssh /etc/ioctl.save \
# /etc/inittab /etc/network /etc/sudoers \
# /etc/init /etc/localtime /etc/dhcpc /etc/pnm2ppa.conf 2>/dev/null
cp -au /etc/ftpusers /KNOPPIX/etc/passwd /KNOPPIX/etc/shadow
/KNOPPIX/etc/group \
/KNOPPIX/etc/ppp /KNOPPIX/etc/isdn /KNOPPIX/etc/ssh \
/KNOPPIX/etc/inittab /KNOPPIX/etc/network /KNOPPIX/etc/sudoers \
/KNOPPIX/sbin/init /KNOPPIX/etc/dhcpc /etc/ 2>/dev/null
------------------------
I tested this by changing password, and after rebooting, the new
password survived the reboot. Just wanted to know what you think about
this method? Could this have been done by any better way? I know about
saveconfig, but my requirement is that even if power failes the configs
should remain.
With warm regards,
raj
#!/static/sh
#
# KNOPPIX General Startup Script
# (C) Klaus Knopper <knoppix@knopper.net>
#
#
# This script needs some of the builtin ash commands (if, test, ...)
# mount/umount, insmod/rmmod are also a builtin in ash-knoppix.
#
# hardcoded configurable options
# Default maximum size of dynamic ramdisk in kilobytes
RAMSIZE=1000000
# End of options
# Don't allow interrupt signals
trap "" 1 2 3 15
# "Safe" SCSI modules in the right order for autoprobe
# Warning: The sym53c8xx.o and g_NCR* cause a kernel Oops if no such adapter
# is present.
#
# NB: It looks like that ncr53c8xx.o is more stable than 53c7,8xx.o for
# a ncr53c810 controller (at least on my installation box it's more
# immune to SCSI timeouts)
# Removed 53c7,8xx -> crashes if no device attached.
# Removed AM53C974 -> crashes tmscsim if adapter found
# Added initio.o on request (untested)
##### Commented out by Raj #####
# SCSI_MODULES="aic7xxx.o aic7xxx_old.o BusLogic.o \
# ncr53c8xx.o NCR53c406a.o \
# initio.o \
# advansys.o aha1740.o aha1542.o aha152x.o \
# atp870u.o dtc.o eata.o fdomain.o gdth.o \
# megaraid.o pas16.o pci2220i.o pci2000.o psi240i.o \
# qlogicfas.o qlogicfc.o qlogicisp.o \
# seagate.o t128.o tmscsim.o u14-34f.o ultrastor.o wd7000.o \
# a100u2w.o 3w-xxxx.o"
SCSI_MODULES=""
# Misc functions
mountit(){
# Usage: mountit src dst "options"
# Uses builtin mount of ash.knoppix
# Builin filesystems
BUILTIN_FS="iso9660 ext2 vfat"
for fs in $BUILTIN_FS; do
test -b $1 && mount -t $fs $3 $1 $2 >/dev/null 2>&1 && return 0
done
return 1
}
FOUND_SCSI=""
FOUND_KNOPPIX=""
INTERACTIVE=""
# Clean input/output
exec >/dev/console </dev/console 2>&1
# Reset fb color mode
RESET="]R"
# ANSI COLORS
# Erase to end of line
CRE="
[K"
# Clear and reset Screen
CLEAR="c"
# Normal color
NORMAL="[0;39m"
# RED: Failure or error message
RED="[1;31m"
# GREEN: Success message
GREEN="[1;32m"
# YELLOW: Descriptions
YELLOW="[1;33m"
# BLUE: System mesages
BLUE="[1;34m"
# MAGENTA: Found devices or drivers
MAGENTA="[1;35m"
# CYAN: Questions
CYAN="[1;36m"
# BOLD WHITE: Hint
WHITE="[1;37m"
# Clear screen with colormode reset
# echo "$CLEAR$RESET"
# echo "$CLEAR"
# Just go to the top of the screen
# echo -n "[H[J"
echo ""
# Be verbose
echo "${WHITE}Welcome to emKnoppix! ${NORMAL}"
echo "${RED}(Use nano for text editor)${NORMAL} "
echo ""
# We only need the builtin commands and /static at this point
PATH=/static
export PATH
umask 022
# Mount /proc and /dev/pts
mount -t proc none /proc
mount -t devpts none /dev/pts
# Read boot command line with builtin cat command (shell read function fails in Kernel 2.4.19-rc1)
CMDLINE="$(cat /proc/cmdline)"
# Check if we are in interactive startup mode
case "$CMDLINE" in *BOOT_IMAGE=expert\ *) INTERACTIVE="yes"; :>/interactive; ;; esac
# Does the user want to skip scsi detection?
NOSCSI=""
case "$CMDLINE" in *noscsi*) NOSCSI="yes"; ;; esac
# Disable kernel messages while probing modules in autodetect mode
echo "0" > /proc/sys/kernel/printk
# Mount module disk
mountmodules(){
TYPE="$1"; shift
echo -n "${CRE}${CYAN}Please insert ${TYPE} modules disk and hit Return. ${NORMAL}"
read a
echo -n "${CRE}${BLUE}Mounting ${TYPE} modules disk... ${NORMAL}"
# We always mount over /modules/scsi (because it's there ;-)
if mountit /dev/fd0 /modules/scsi "-o ro"; then
echo "${GREEN}OK.${NORMAL}"
return 0
fi
echo "${RED}NOT FOUND.${NORMAL}"
return 1
}
# Unmount module disk
umountmodules(){
TYPE="$1"; shift
echo -n "${CRE}${BLUE}Unmounting ${TYPE} modules disk... ${NORMAL}"
umount /modules/scsi 2>/dev/null
echo "${GREEN}DONE.${NORMAL}"
}
# Ask user for modules
askmodules(){
TYPE="$1"; shift
echo "${BLUE}${TYPE} modules available:${WHITE}"
c=""; for m in "$@"; do
if test -f "/modules/scsi/$m"; then
test -z "$c" && { echo -n " $m"; c="1"; } || { echo " $m"; c=""; }
fi
done
[ -n "$c" ] && echo ""
echo "${CYAN}Load ${TYPE} Modules?${NORMAL}"
echo "${CYAN}[Enter full filename(s) (space-separated), Return for autoprobe, ${WHITE}n${CYAN} for none] ${NORMAL}"
echo -n "${CYAN}insmod module(s)> ${NORMAL}"
read MODULES
case "$MODULES" in n|N) MODULES=""; ;; y|"") MODULES="$*"; ;; esac
}
# Try to load the given modules (full path or current directory)
loadmodules(){
TYPE="$1"; shift
test -n "$INTERACTIVE" && echo "6" > /proc/sys/kernel/printk
for i in "$@"; do
echo -n "${CRE}${BLUE}Probing ${TYPE}... ${MAGENTA}$i${NORMAL}"
if test -f /modules/scsi/$i && insmod -f /modules/scsi/$i >/dev/null 2>&1
then
echo "${CRE} ${GREEN}Found ${TYPE} device(s) handled by ${MAGENTA}$i${GREEN}.${NORMAL}"
case "$TYPE" in scsi|SCSI) FOUND_SCSI="yes"; ;; esac
fi
done
test -n "$INTERACTIVE" && echo "0" > /proc/sys/kernel/printk
echo -n "${CRE}"
}
# Mount the /etc from harddisk
echo ${RED} Mounting etc from harddisk ${NORMAL}
mount -t ext2 /dev/hda6 /etc
# Check for SCSI, use modules on bootfloppy first
if test -n "$INTERACTIVE"; then
# Let the user select interactively
askmodules SCSI $(cd /modules/scsi; echo *.o)
else
# these are the autoprobe-safe modules
MODULES="$SCSI_MODULES"
fi
test -z "$NOSCSI" && test -n "$MODULES" && loadmodules SCSI $MODULES
# End of SCSI check
# Check for misc modules in expert mode
if test -n "$INTERACTIVE"; then
another=""; answer=""
while test "$answer" != "n" -a "$answer" != "N"; do
echo -n "${CYAN}Do you want to load additional modules from$another floppy disk? [${WHITE}Y${CYAN}/n] ${NORMAL}"
another=" another"
read answer
case "$answer" in n*|N*) break; ;; esac
if mountmodules new; then
askmodules new $(cd /modules/scsi; echo *.o)
test -n "$MODULES" && loadmodules new $MODULES
umountmodules current
fi
done
fi
# All interactively requested modules should be loaded now.
# Check for ide-scsi supported CD-Roms et al.
test -f /proc/scsi/scsi && FOUND_SCSI="yes"
# Disable kernel messages again
echo "0" > /proc/sys/kernel/printk
# Now that the right SCSI driver is (hopefully) loaded, try to find CDROM
DEVICES="/dev/hd?"
test -n "$FOUND_SCSI" && DEVICES="/dev/scd? /dev/scd?? $DEVICES"
# New: Also try parallel port CD-Roms [for Mike].
DEVICES="$DEVICES /dev/pcd?"
# New: also check HD partitions for a KNOPPIX/KNOPPIX image
test -n "$FOUND_SCSI" && DEVICES="$DEVICES /dev/sd?[1-9] /dev/sd?[1-9][0-9]"
## - Raj ##
# DEVICES="$DEVICES /dev/hd?[1-9] /dev/hd?[1-9][0-9]"
DEVICES="/dev/hd?[1-9] /dev/hd?[1-9][0-9]"
## ---- ###
for i in $DEVICES
do
echo -n "${CRE}${BLUE}Looking for CDROM in: ${MAGENTA}$i${NORMAL} "
if mountit $i /cdrom "-o ro" >/dev/null 2>&1
then
if test -d /cdrom/KNOPPIX
then
echo -n "${CRE} ${GREEN}Accessing KNOPPIX CDROM at ${MAGENTA}$i${GREEN}...${NORMAL}"
FOUND_KNOPPIX="$i"
break
fi
umount /cdrom
fi
done
# Harddisk-installed script part version has been removed
# (KNOPPIX can be booted directly from HD now).
if test -n "$FOUND_KNOPPIX" -a -f /cdrom/KNOPPIX/KNOPPIX; then
# DEBUG
# echo "6" > /proc/sys/kernel/printk
insmod -f /modules/cloop.o file=/cdrom/KNOPPIX/KNOPPIX
mountit /dev/cloop /KNOPPIX "-o ro" || FOUND_KNOPPIX=""
fi
# Final test if everything succeeded.
if test -n "$FOUND_KNOPPIX"
then
# copy library cache
cat /KNOPPIX/etc/ld.so.cache > /etc/ld.so.cache
echo ""
# Enable kernel messages
echo "6" > /proc/sys/kernel/printk
# Set paths
echo -n "${CRE}${BLUE}Setting paths...${NORMAL}"
PATH="/sbin:/bin:/usr/sbin:/usr/bin:/usr/X11R6/bin:."
export PATH
# Debian weirdness
/bin/cp -a /KNOPPIX/etc/alternatives /etc/ 2>/dev/null
# From here, we should have all essential commands available.
hash -r
# Clean up /
rm -rf /modules /static
# New in Kernel 2.4.x: tempfs with variable ramdisk size.
# We check for available memory anyways and limit the ramdisks
# to a reasonable size.
FOUNDMEM="$(awk '/MemTotal/{print $2}' /proc/meminfo)"
TOTALMEM="$(awk 'BEGIN{m=0};/MemFree|Cached/{m+=$2};END{print m}' /proc/meminfo)"
# Be verbose
echo "${CRE}${BLUE}Total memory found: ${YELLOW}${FOUNDMEM}${BLUE} kB${NORMAL}"
# Now we need to use a little intuition for finding a ramdisk size
# that keeps us from running out of space, but still doesn't crash the
# machine due to lack of Ram
# Minimum size of additional ram partitions
MINSIZE=2000
# At least this much memory minus 30% should remain when home and var are full.
MINLEFT=16000
# Maximum ramdisk size
MAXSIZE="$(expr $TOTALMEM - $MINLEFT)"
# Default ramdisk size for ramdisk
RAMSIZE="$(expr $TOTALMEM / 5)"
# Check for sufficient memory to mount extra ramdisk for /home + /var
if test -n "$TOTALMEM" -a "$TOTALMEM" -gt "$MINLEFT"; then
test -z "$RAMSIZE" && RAMSIZE=1000000
mkdir -p /ramdisk
# tmpfs/varsize version, can use swap
RAMSIZE=$(expr $RAMSIZE \* 4)
echo -n "${CRE}${BLUE}Creating ${YELLOW}/ramdisk${BLUE} (dynamic size=${RAMSIZE}k) on ${MAGENTA}/dev/shm${BLUE}...${NORMAL}"
# We need /bin/mount here for the -o size= option
/bin/mount -t tmpfs -o "size=${RAMSIZE}k" /dev/shm /ramdisk && mkdir -p /ramdisk/home /ramdisk/var && ln -s /ramdisk/home /ramdisk/var /
echo "${BLUE}Done.${NORMAL}"
else
mkdir -p /home /var
fi
echo -n "${CRE}${BLUE}Creating directories and symlinks on ramdisk...${NORMAL}"
# Create common WRITABLE (empty) dirs
mkdir -p /var/run /var/backups /var/local \
/var/preserve /var/state/misc /var/tmp /var/lib \
/home/knoppix /home/root /etc/sysconfig
chown knoppix.knoppix /home/knoppix
# Create empty utmp and wtmp
:> /var/run/utmp
:> /var/run/wtmp
# Not Reqd - raj # CUPS wants writable files. :-/
# cp -a /KNOPPIX/etc/cups/*.conf /etc/cups/ 2>/dev/null
# All files in here should be size zero after Knoppix.clean was run
cp -a /KNOPPIX/var/local /KNOPPIX/var/log \
/KNOPPIX/var/spool /var/ 2>/dev/null
cp -a /KNOPPIX/var/lib/dhcp* \
/var/lib/ 2>/dev/null
# Problematic directories in /var/lib (lots and lots of inodes)
ln -s /KNOPPIX/var/lib/dpkg /KNOPPIX/var/lib/apt /KNOPPIX/var/lib/doc-base \
/var/lib/ 2>/dev/null
# Debian-apt
ln -s /KNOPPIX/var/cache/apt /var/cache/ 2>/dev/null
ln -s /KNOPPIX/etc/skel /etc/dhcpc/resolv.conf \
/etc/ 2>/dev/null
ln -s /KNOPPIX/dev/* /dev/ 2>/dev/null
# Index files can be HUGE, so better replace cache/man tree by links later
# cp -a /KNOPPIX/var/cache/man /var/cache/ 2>/dev/null
# Create links from CDROM for UNWRITABLE (remaining) files
cp -aus /KNOPPIX/var/* /var/ 2>/dev/null
cp -aus /KNOPPIX/etc/* /etc/ 2>/dev/null
# Make SURE that these are files, not links!
#rm -rf /etc/ftpusers /etc/passwd /etc/shadow /etc/group \
# /etc/ppp /etc/isdn /etc/ssh /etc/ioctl.save \
# /etc/inittab /etc/network /etc/sudoers \
# /etc/init /etc/localtime /etc/dhcpc /etc/pnm2ppa.conf 2>/dev/null
cp -au /etc/ftpusers /KNOPPIX/etc/passwd /KNOPPIX/etc/shadow /KNOPPIX/etc/group \
/KNOPPIX/etc/ppp /KNOPPIX/etc/isdn /KNOPPIX/etc/ssh \
/KNOPPIX/etc/inittab /KNOPPIX/etc/network /KNOPPIX/etc/sudoers \
/KNOPPIX/sbin/init /KNOPPIX/etc/dhcpc /etc/ 2>/dev/null
# Extremely important, init crashes on shutdown if this is only a link
:> /etc/ioctl.save
:> /etc/pnm2ppa.conf
# Diet libc bug workaround
cp -f /KNOPPIX/etc/localtime /etc/localtime
echo "${BLUE}Done.${NORMAL}"
# Now tell kernel where the real modprobe lives
echo "/sbin/modprobe" > /proc/sys/kernel/modprobe
# Change root device from /dev/fd0 to /dev/ram0
echo "0x100" > /proc/sys/kernel/real-root-dev
# Give control to the init process.
echo "${CRE}${BLUE}Starting init process.${NORMAL}"
rm -f /linuxrc
exit 0
else
echo "${CRE}${RED}Can't find KNOPPIX filesystem, sorry.${NORMAL}"
echo "${RED}Dropping you to a (very limited) shell.${NORMAL}"
echo "${RED}Press reset button to quit.${NORMAL}"
echo ""
echo "Additional builtin commands avaliable:"
echo " cat mount umount"
echo " insmod rmmod lsmod"
echo ""
PS1="knoppix# "
export PS1
echo "6" > /proc/sys/kernel/printk
# Allow signals
trap 1 2 3 15
exec /static/ash
fi
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