If It's Not Backed Up, Did It Even Exist?

dd if=/dev/sda | gzip -c > /media/user/SYS_BK/backup.img

#!/bin/bash
# ----------------------------------------------------------------------
# makes handy rotating-filesystem-snapshot utility
# ----------------------------------------------------------------------
# slightly variation of http://www.mikerubel.org/computers/rsync_snapshots
# ----------------------------------------------------------------------
unset PATH;

# ------------- system commands used by this script --------------------
ID=/usr/bin/id;
ECHO=/bin/echo;
RM=/bin/rm;
MV=/bin/mv;
CP=/bin/cp;
TOUCH=/usr/bin/touch;
RSYNC=/usr/bin/rsync;
LS=/bin/ls;
GREP=/usr/bin/grep;
WC=/usr/bin/wc;
MKDIR=/bin/mkdir;
TR=/usr/bin/tr;
HEAD=/usr/bin/head;
TAIL=/usr/bin/tail;
CURL=/usr/bin/curl;
DU=/usr/bin/du;
CUT=/usr/bin/cut;
FIND=/usr/bin/find;
DATE=/usr/bin/date;
DF=/usr/bin/df;
FINDMNT=/usr/bin/findmnt

# ------------- script setup ---------------------------------------------
MOUNT_DEVICE=/media/user/HDD_2;
SOURCE=/media/user/SSD/data/;
SNAPSHOT_RW=/media/user/HDD_2/snapshot;
EXCLUDES=/home/user/server-config/backup_exclude;
BACKUPS_NUM=4;
NTFY_ADDR="192.168.1.108:19492/backup";

# ------------- script parameters ----------------------------------------
VERBOSITY="";
BACKUP_NAME="backup";
NOTIFY_TIME="DELAY: 10s";
while [ $# -gt 0 ]; do
  case "$1" in
    -v|--verbosity)
      VERBOSITY="v";
      ;;
    -n=*|--name=*)
      BACKUP_NAME="${1#*=}";
      ;;
    -t=*|--time=*)
      NOTIFY_TIME="${1#*=}";
      ;;
    *)
      $ECHO "Error: Invalid argument";
      exit 1;
  esac
  shift
done

# ------------- functions ------------------------------------------------
function notify() {
    if [[ $2 -eq 0 ]]; then
      TAG="tada";
    else
      TAG="rotating_light";
    fi;
    $CURL -s \
      -H "Title: Backup report" \
      -H "Tags: $TAG" \
      -H "$NOTIFY_TIME" \
      -d "$1" \
      $NTFY_ADDR & 
}

function handle_rsync_error() {
    case $1 in
        1)
            ERRORMESSAGE="Syntax or usage error"
        ;;
        2)
            ERRORMESSAGE="Protocol incompatibility"
        ;;
        3)
            ERRORMESSAGE="Errors selecting input/output files, dirs"
        ;;
        4)
            ERRORMESSAGE="Requested action not supported: an attempt was made to manipulate 64-bit files on a platform that cannot support them; or  an option  was specified that is supported by the client and not by the server."
        ;;
        5)
            ERRORMESSAGE="Error starting client-server protocol"
        ;;
        6)
            ERRORMESSAGE="Daemon unable to append to log-file"
        ;;
        10)
            ERRORMESSAGE="Error in socket I/O"
        ;;
        11)
            ERRORMESSAGE="Error in file I/O"
        ;;
        12)
            ERRORMESSAGE="Error in rsync protocol data stream"
        ;;
        13)
            ERRORMESSAGE="Errors with program diagnostics"
        ;;
        14)
            ERRORMESSAGE="Error in IPC code"
        ;;
        20)
            ERRORMESSAGE="Received SIGUSR1 or SIGINT"
        ;;
        21)
            ERRORMESSAGE="Some error returned by waitpid()"
        ;;
        22)
            ERRORMESSAGE="Error allocating core memory buffers"
        ;;
        23)
            ERRORMESSAGE="Partial transfer due to error"
        ;;
        24)
            ERRORMESSAGE="Partial transfer due to vanished source files"
        ;;
        25)
            ERRORMESSAGE="The --max-delete limit stopped deletions"
        ;;
        30)
            ERRORMESSAGE="Timeout in data send/receive"
        ;;
        137)
            ERRORMESSAGE="Fehlercode 137 :: No clear errorcode. Possible reason: The Rsync process might have crashed."
        ;;
        *)
            ERRORMESSAGE="An unidentifed error occured - maybe a new errorcode due to a new version of rsync"
        ;;
    esac

    if [[ $1 -ne 0 ]]; then
        $ECHO "Error while performing the backup. Error: $ERRORMESSAGE";
        notify "Error while performing the backup. Error: $ERRORMESSAGE" 1;
        exit 2;
    fi;
}

# ------------- the script itself ----------------------------------------
START=$($DATE +%s);

# make sure we're running as root
if (( `$ID -u` != 0 )); then { $ECHO "Sorry, must be root. Exiting..."; exit 3; } fi

# exit if the backup directory is not available or it's not a mount point
if [[ ! -d $MOUNT_DEVICE ]]; then
  $ECHO "Error: $MOUNT_DEVICE does not exist.";
  notify "Error: $MOUNT_DEVICE does not exist." 1;
  exit 4;
fi;

if [[ $($FINDMNT -o TARGET --noheadings --first-only --evaluate $MOUNT_DEVICE) != $MOUNT_DEVICE ]]; then
  $ECHO "ERROR: $MOUNT_DEVICE is not a mount point.";
  notify "ERROR: $MOUNT_DEVICE is not a mount point." 1;
  exit 5;
fi

# if the snapshot directory does not exists, create it
if [[ ! -d $SNAPSHOT_RW ]]; then
    $MKDIR -p $SNAPSHOT_RW;
fi;

# rotating snapshots

# step 1: delete the oldest snapshot, if it exists and maximum number of backup reached:
if [[ -d $SNAPSHOT_RW/$BACKUP_NAME.$BACKUPS_NUM && -d $SNAPSHOT_RW/$BACKUP_NAME.1 ]]; then
    $RM -rf $SNAPSHOT_RW/$BACKUP_NAME.1;
fi;

# step 2: if maximum number of backup reached then
# shift the middle snapshot(s) back by one, if they exist
if [[ -d $SNAPSHOT_RW/$BACKUP_NAME.$BACKUPS_NUM ]]; then
    for (( i=2; i<=$BACKUPS_NUM; i++ )); do
        if [[ -d $SNAPSHOT_RW/$BACKUP_NAME.$i ]]; then
            $MV $SNAPSHOT_RW/$BACKUP_NAME.$i $SNAPSHOT_RW/$BACKUP_NAME.$(($i-1));
        fi;
    done;
fi;

ACTUAL_BACKUPS_NUM=$($LS $SNAPSHOT_RW | $GREP "^$BACKUP_NAME" | $WC -l | $TR -d " ");
if [[ ! -d $SNAPSHOT_RW/$BACKUP_NAME.$(($ACTUAL_BACKUPS_NUM + 1)) ]]; then
    $MKDIR -p $SNAPSHOT_RW/$BACKUP_NAME.$(($ACTUAL_BACKUPS_NUM + 1))$SOURCE;
fi;

# step 4: rsync from the system into the latest snapshot (notice that
# rsync behaves like cp --remove-destination by default, so the destination
# is unlinked first.  If it were not so, this would copy over the other
# snapshot(s) too!
$RSYNC -a$VERBOSITY \
    --delete \
    --delete-excluded \
    --exclude-from="$EXCLUDES" \
    --link-dest="$SNAPSHOT_RW/$BACKUP_NAME.$(($ACTUAL_BACKUPS_NUM))$SOURCE" \
    $SOURCE $SNAPSHOT_RW/$BACKUP_NAME.$(($ACTUAL_BACKUPS_NUM + 1))$SOURCE;

handle_rsync_error $?;

# step 5: update the mtime of latest backup to reflect the snapshot time
$TOUCH $SNAPSHOT_RW/$BACKUP_NAME.$(($ACTUAL_BACKUPS_NUM + 1));

TOTAL_SIZE_BACKUP_NAME_ONLY=$($DU -sch $SNAPSHOT_RW/$BACKUP_NAME* | $TAIL -n 1 | $CUT -f 1);
TOTAL_BACKUPS_BACKUP_NAME_ONLY=$($LS $SNAPSHOT_RW | $GREP "^$BACKUP_NAME" | $WC -l | $TR -d " ");
TOTAL_FILES_BACKUP_NAME_ONLY=$($FIND $SNAPSHOT_RW/$BACKUP_NAME* -type f | $WC -l | $TR -d " ");

TOTAL_SIZE=$($DU -sh $SNAPSHOT_RW | $CUT -f 1);
TOTAL_BACKUPS=$($LS $SNAPSHOT_RW | $WC -l | $TR -d " ");
TOTAL_FILES=$($FIND $SNAPSHOT_RW -type f | $WC -l | $TR -d " ");

USAGE_PERCENTAGE=$($DF $SNAPSHOT_RW | $GREP $MOUNT_DEVICE | $TR -s " " | $CUT -d " " -f 5);
END=$($DATE +%s);
ELAPSED=$(($END-$START));

notify "Backup done successfully in $ELAPSED seconds.

Total size of $TOTAL_BACKUPS_BACKUP_NAME_ONLY $BACKUP_NAME $BACKUP_NAME_BACKUP_NAME_ONLY backups: $TOTAL_SIZE_BACKUP_NAME_ONLY ($TOTAL_FILES_BACKUP_NAME_ONLY files).

Total size of $TOTAL_BACKUPS backups: $TOTAL_SIZE ($TOTAL_FILES files).

Percentage of disk usage: $USAGE_PERCENTAGE" 0;