DSL Ideas and Suggestions :: Improving DSL fallover recover

Here's some rough notes towards implementing the above, *untested*. (I have no idea as yet, for example, about possible effects of calling shutdown -c )

Function check_sufficient_space could be called in filetool.sh right after 'if [ $1 == "backup" ] ; then'

Code Sample

check_sufficient_space(){

TARERR=/tmp/tarerr.$$

tar -C / -T $HOME/.filetool.lst -X $HOME/.xfiletool.lst --totals -cf - 1>/dev/null 2>${TARERR}

ARCHSIZE=$(awk '/Total bytes written/{print $4}' ${TARERR} )
[ -z "$ARCHSIZE" ] && echo "Nothing to backup?"
rm -f ${TARERR}

(( ARCHK=ARCHSIZE/1000 )) # want kB
(( ARCHSIZEK = ARCHK + 1 )) # round upwards

FREESPACE=$(df -k $MOUNTPOINT | awk '/dev/{print $4}')

echo "Max upper bound on backup size = $ARCHSIZEK kB"
echo "Available space on $MOUNTPOINT = $FREESPACE kB"

if [ "$ARCHSIZEK" -ge "$FREESPACE" ]; then
# Needs a flua gui or something here
echo "WARNING: there may be insufficient space on $MOUNTPOINT for backup."
while true; do
echo "Proceed anyway? (y/n)"
read ANS
case $ANS in
n|N|n*|N*) echo "Aborting backup/shutdown .."
sudo shutdown -c
if [ $MOUNTED == "no" ]; then
sudo umount $MOUNTPOINT
fi
exit 1;;
y|Y|y*|Y*) break;;
*) echo "Invalid response.";;
esac
done
fi
}

After a little testing, first problem:

'shutdown -c' doesn't abort the shutdown running from this script, it can't find a pid for the running shutdown. One for tomorrow.

'shutdown' isn't running by that stage, init 0 has already been called (doh). Can get out of shutdown by changing runlevels (see below).

A flag could be set somewhere (eg /etc/sysconfig) to prevent a restore from occuring when runlevel 5 starts up again, otherwise some files which were changed during the session might get overwritten by the restore.

Function call:

Code Sample

.
(snip)
trap failed SIGTERM

if [ $1 == "backup" ]; then
check_sufficient_space
(snip)

Skip restore if backup had been aborted:

Code Sample

(snip)
if [ $1 == "restore" ]; then
if [ -e /etc/sysconfig/abortedbackup ]; then
sudo rm -f /etc/sysconfig/abortedbackup
else
if [ -f /etc/sysconfig/des ]; then
TARGETFILE="backup.des"
(snip)
.
.
(snip)
echo "${BLUE}Done.${NORMAL}"
fi
fi
clean_up 0
fi
echo "I don't understand the command line parameter: $1"
(snip)

Function:

Code Sample

check_sufficient_space(){

TARERR=/tmp/tarerr.$$
tar -C / -T $HOME/.filetool.lst -X $HOME/.xfiletool.lst --totals -cf - 1>/dev/null 2>${TARERR}
ARCHSIZE=$(awk '/Total bytes written/{print $4}' ${TARERR} )
rm -rf ${TARERR}

if [ $ARCHSIZE -eq 0 ]; then echo "Nothing to backup?"; clean_up; fi

(( ARCHK=ARCHSIZE/1000 )) # want kB
(( ARCHSIZEK = ARCHK + 1 )) # round upwards

FREESPACE=$(df -k $MOUNTPOINT | awk '/dev/{print $4}')

echo "Max upper bound on backup size = $ARCHSIZEK kB"
echo "Available space on $MOUNTPOINT = $FREESPACE kB"

if [ $ARCHSIZEK -ge $FREESPACE ]; then
a=$(runlevel)
if [ ${a#*[ ]} -eq 5 ]; then
# Backing up from gui
:
# ------- eg flua GUI goes here which just exits script if user aborts backup -------------
else
# We are in shutdown/reboot
echo "WARNING: there may be insufficient space on $MOUNTPOINT for backup."
while true; do
echo -n "Proceed anyway? (y/n) "
read ANS
case $ANS in
n|N|n*|N*) echo "Aborting backup/shutdown .."
if [ $MOUNTED == "no" ]; then
sudo umount $MOUNTPOINT
fi
sudo touch /etc/sysconfig/abortedbackup
exec >/dev/null # prevents trapped "failed" message when init kills this script
sudo telinit ${a%[ ]*};; # back to previous runlevel (normally 5 )
y|Y|y*|Y*) break;;
*) echo "Invalid response.";;
esac
done
fi
fi
}

If anyone feels like testing the above that might be useful.

Another method (if switching runlevels about turns out to have problems) might be to move backup/restore out of the shutdown scripts altogether, and instead run filetool.sh from exitcheck.sh, before shutdown is called. However this means that (for eg) if a shutdown is initiated by some means other than the menu (eg CNTRL-ALT-DEL), a backup will not occur at all, so imho this is not preferable.

original here.