Как сделать резервную копию и что именно надо резервировать?

#! /bin/bash
##  Backup script for Gentoo Linux
# Last modification 2008.11.09
# Added check 'qlist' command exist and run saving list of installed packages with your USE-flags
# Added "new" excluded dir - /usr/src, /usr/portage
basename=$(basename $0)
# these are the commands we actually need for the backup
command_list=(cut date dd echo find grep hostname mount mkdir qlist sfdisk sh split tar umount uname which)
# verify that each command we use exists. if one can't be found use $PATH and make a suggestion if possible.
for command in ${command_list[@]}; do
        if [ ! -x "$(which $command 2>&1)" ]; then
                echo -e "\nERROR: $command not found! "
                base=$(basename $command)
                if [ "$(which $base 2>&1 | grep "no $(basename $command) in")" != "" ]; then
                        echo -e "ERROR: $base is not in your \$PATH."
                fi
                exit -1
        fi
done
#
###############################################################################################################
##  This is a script to create a custom stage 4 tarball (System and boot backup)
##  Please check the options and adjust to your specifics.
echo "-=- Starting the Backup Script..."
echo "-=-"
echo "-=- Setting the variables..."
## Where MBR is written.
disk_with_mbr="/dev/sda"
##  The location of the stage 4 tarball.
##  Be sure to include a trailing /
patch_to_backup=/home/users/backup/
stage_for_location=$(date +%F)_system
if [ ! -d ${patch_to_backup}${stage_for_location} ];
    then
        if mkdir -p ${patch_to_backup}${stage_for_location};
            then
                backup_dir=${patch_to_backup}${stage_for_location}/
                ##  The name of the stage 4 tarball.
                archive=${backup_dir}$(hostname)-stage4.tar.bz2
                echo "-=- Backup directory ${backup_dir} created..."
            else
                echo "-=- Can't create ${backup_dir}. Please check ..."
                exit 1
        fi
    else
        if [ -f ${archive} ];
            then
                echo "-=- Backup file ${archive} exist, nothing to do..."
                exit 1
        fi
fi    
##  The name of the stage 4 tarball.
##archive=${backup_dir}$(hostname)-stage4.tar.bz2
##  Directories/files that will be exluded from the stage 4 tarball.
##
##  Add directories that will be recursively excluded, delimited by a space.
##  Be sure to omit the trailing /
dir_excludes="
/mnt/*
/dev
/lost+found
/proc
/sys
/tmp
/home
/usr/src
/var/tmp
/var/run"
##
##  Add files that will be excluded, delimited by a space.
##  You can use the * wildcard for multiple matches.
##  There should always be $archive listed or bad things will happen.
file_excludes="${archive}"
##
##  Combine the two *-excludes variables into the $excludes variable
excludes="$(for i in ${dir_excludes}; do if [ -d $i ]; then \
    echo -n " --exclude=$i/*"; fi; done) $(for i in ${file_excludes}; do \
    echo -n " --exclude=$i"; done)"
##  The options for the stage 4 tarball.
tar_options="${excludes} --create --absolute-names --preserve-permissions --bzip2 --verbose --totals --file"
echo "-=- Done!"
echo "-=-"
##  Mounting the boot partition
echo "-=- Mounting boot partition, then sleeping for 5 seconds..."
mount /boot
sleep 5
echo "-=- Done!"
echo "-=-"
##  Creating a copy of the boot partition (copy /boot to /bootcpy).
##  This will allow the archiving of /boot without /boot needing to be mounted.
##  This will aid in restoring the system.
echo "-=- Copying /boot to /bootcpy ..."
cp -R /boot /bootcpy
echo "-=- Done!"
echo "-=-"
echo "-=- Copying kernel config to /bootcpy ..."
zcat /proc/config.gz > /bootcpy/config_$(uname -r)
echo -=- Done!
echo -=-
echo "-=- Write list of installed packages ..."
qlist -CU > ${backup_dir}installed_packages.txt
echo "-=- Done!"
##
echo "-=- Write README.txt ..."
echo "For fix "Warning: unable to open an initial console."" >> ${backup_dir}Readme.txt
echo "run /usr/local/sbin/fix_console.sh" >> ${backup_dir}Readme.txt
echo "-=- Done!"
##  Unmounting /boot
echo "-=- Unmounting /boot then sleeping for 5 seconds..."
umount /boot
sleep 5
echo "-=- Done!"
echo "-=-"
##  Creating the stage 4 tarball.
echo "-=- Creating custom stage 4 tarball \=\=\> ${archive}"
echo "-=-"
echo "-=- Running the following command:"
echo "-=- tar ${tar_options} ${archive} /"
tar ${tar_options} ${archive} /;
echo "-=- Done!"
##  Uncomment this portion to encrypt the stage4 using asymmetric encryption with GnuPG
##  To get a list of available ciphers on your machine do #gpg --version
##  Note: only aes aes192 aes256 and twofish should be used for large files (~1Gig & larger)
##  To Restore: (cat together if split) and #gpg stage4.tar.bz2.gpg
#echo -=- Starting Encryption Process usung asymmetric encryption with a public key  -=-
#cd $stage4Location
#gpg --encrypt --batch --recipient [MY_PUB_KEY] --cipher-algo twofish --output $archive.gpg $archive
#rm $archive
#archive=$stage4Location$(hostname)-stage4.tar.bz2.gpg
##  Uncomment this portion to encrypt the stage4 using symmetric encryption with GnuPG
##  ##  To get a list of ciphers on your machine do #gpg --version
##  Note: only aes aes192 aes256 and Twofish should be used for large files (~1 gig & larger)
##  To Restore: (cat together if split) and #gpg stage4.tar.bz2.gpg
#echo -=- Starting Encryption Process usung symmetric encryption with a password  -=-
#cd $stage4Location
#pass=PLEASE_CHANGE_ME_I_BEG_YOU!
#echo $pass | gpg --batch --cipher-algo twofish --passphrase-fd 0 --symmetric $archive
#rm $archive
#archive=$stage4Location$(hostname)-stage4.tar.bz2.gpg
##  Split the stage 4 tarball in cd size tar files.
##  To combine the tar files after copying them to your
##  chroot do the following: "cat *.tar.bz2 >> stage4.tar.bz2".
##  or if encrypted do the following: "cat *.tar.bz2.gpg >> stage4.tar.bz2.gpg".
##  Uncomment the following lines to enable this feature.
#echo -=- Splitting the stage 4 tarball into CD size tar files...
#split --bytes=700000000 ${archive} ${archive}.
#echo -=- Done!
##  Removing the directory /bootcpy.
##  You may safely uncomment this if you wish to keep /bootcpy.
echo "-=- Removing the directory /bootcpy ..."
rm -rf /bootcpy
echo "-=- Done!"
echo "-=-"
##
## To store partition table info:
## The first of those saves the mbr and the second will store all partition info (including logical partitions,
## which aren't part of the mbr).
echo "-=- Store MBR and partition table info ..."
dd if=${disk_with_mbr} of=${backup_dir}mbr.save count=1 bs=512
sfdisk -d ${disk_with_mbr} > ${backup_dir}partitions.save
echo "-=- Done!"
echo "-=-"
##  This is the end of the line.
echo "-=- The Backup Script has completed!"

#!/bin/sh
# Если в консоли появилась такая запись 
# Warning: unable to open an initial console.
mkdir /mnt/fixit
mount --bind / /mnt/fixit 
rm -fr /mnt/fixit/dev/* #насчёт этого не уверен, что обязательно надо делать
cd /mnt/fixit/dev
mknod -m 600 console c 5 1 && chown root:tty console
mknod -m 600 initctl p
mknod -m 666 null c 1 3 
mv -f /etc/issue.devfix /etc/issue 
cd /
umount /mnt/fixit
rmdir /mnt/fixit
reboot