automated backup of mysql and web site content to dropbox under text mode

I used to run a personal web site on a linux VPS, below is how I backup my sites and database content to dropbox.
(please note, not all these ideas came from me, I came across a few sources from internet and just put it together and make it work for me)

1. install dropbox on linux, see http://www.dropboxwiki.com/Text_Based_Linux_Install#Post-installation, I use folder /var/backup/Dropbox as dropbox folder.
2. use crontab to backup mysql and web content to dropbox folder, use compression to reduce bandwidth usage.
3. you can also you crontab to remove old backup files automatically.

purgeDropbox.sh:

#!/bin/bash

# limit on the size (in KB) of the directory

limit=1572864

adminmail=webmaster@yourdomain.com

# if directory exists, find out it's size

if [ -d /var/backup/Dropbox ]

then

  size=$(/usr/bin/du -sk /var/backup/Dropbox | cut -f1)

else

  echo "/var/backup/Dropbox is invalid !!!" | /bin/mail -s "Invalid directory" $adminmail

  exit

fi

# if directory size is greater than limit, alert the user

if [ $size -gt $limit ]

then

  echo "Data volume in your user home dir /var/backup/Dropbox with a total size of  ${size} kB exceeds the maximum limit of $limit kB (1.5 GB) ! Please take action!" |

 /bin/mail -s "user home dir exceeds max limit" $adminmail

   find /var/backup/Dropbox/redmine -name "*.gz" -mtime +30 -exec rm {} \; >> /root/purge.log 2>&1

fi

crontab entries:

30 20 * * *  mysqldump -u root -pPASSWORD --databases db1 db2 |gzip >/var/backup/Dropbox/database_$(date +\%Y\%m\%d__\%H:\%M:\%S\%z).sql.gz
00 19 * * * /root/purgeDropbox.sh

00 22 * * *  /bin/tar czfv /var/backup/Dropbox/web_$(date  +\%Y\%m\%d__\%H:\%M:\%S\%z).tar.gz /var/www