backup.sh

#!/bin/sh
SERVER=backup@squee.decafninja.com
CLIENT=`hostname`
NAME=`hostname -s`

. /var/backups/backup.conf

SERVER_ROOT="/var/backups/systems/$NAME"
SSH_OPT="-i /var/backups/.ssh/id_rsa"

DATE=`date "+%Y-%m-%dT%H%M%S"`

EXCLUDE_OPTS=""
for excludepath in $EXCLUDE; do
    EXCLUDE_OPTS="$EXCLUDE_OPTS --exclude=$excludepath"
done

set -x
for FS in $FILESYSTEMS; do
    PREV_BACKUP=`ssh $SSH_OPT $SERVER "ls -atd $SERVER_ROOT/backup* | head -1"`
    RSYNC_OPTS="$EXCLUDE_OPTS"
    if [ "x$PREV_BACKUP" != "x" ]; then
        RSYNC_OPTS="$RSYNC_OPTS --link-dest=$PREV_BACKUP"
    fi

    TARGET_FS=$FS
    if [ "x$FS"x == "x/x" ] ; then
        TARGET_FS=/root
    fi

    BACKUP_ROOT=$SERVER_ROOT/backup-$DATE
    COMPLETE=$BACKUP_ROOT/$TARGET_FS
    INCOMPLETE=$COMPLETE-incomplete
    CURRENT=$SERVER_ROOT/current$TARGET_FS

    ssh $SSH_OPT $SERVER "mkdir -p $BACKUP_ROOT $SERVER_ROOT/current" \
        && rsync --archive --one-file-system --hard-links \
            --human-readable --inplace --numeric-ids --delete \
            --compress -e "ssh $SSH_OPT" \
            $RSYNC_OPTS \
            $FS/ \
            $SERVER:$INCOMPLETE \
        && ssh $SSH_OPT $SERVER "mv $INCOMPLETE $COMPLETE && rm -f $CURRENT && ln -s $COMPLETE $CURRENT"
done