Having been bitten a few times by not backing data up, I’m now pretty anal about making sure my servers are backed up.
First, a little bit of background. My network consists of a large number of linux boxes (mostly debian and ubuntu), and various windows servers running anything from XP, to 2000 and 2003. I have one dedicated linux machine which is a backup server running debian. Some backups are ‘put’ onto the backup server at predefined intervals over samba, nfs, and ftp, and others are ‘retrieved’ by scripts on the backup server. Every day these backups are copied to 2 usb drives (both encrypted with truecrypt) and taken off site.
As rebuilding a server is a fairly quick task (especially ubuntu, which can be installed and configured from scratch in under 20 minutes), I only back up the necessary configuration files and data, as doing full images of every server would need a huge amount of storage.
Firstly, the backup server itself needs to be configured to run samba, nfs, and ftpd. Setting these up is fairly trivial and won’t be covered here but I will write guides to setting these up in the very near future. As a side note, we have recently switched from a backup ‘server’ to a QNAS network storage device. As this runs linux it’s more than capable of running the necessary cron jobs for the ‘get’ server backups. Plus it also comes preconfigured with samba, nfs, timecapsule, and ftp.
So, on to the backing up. All of my windows machines are part of the ‘get’ backups, where the backup server itself connects to the client and fetches the backup. To achieve this, I simply create network shares on the client machines, then do something similar to the following:
mount -t smbfs //svr2/share /mnt/backup
tar -zcvf /home/backups/svr2.tgz /mnt/backup/* -R
umount /mnt/backup
I have this saved as a shell script which runs every night to fetch a backup of the necessary data from the windows machine. Note that this method can be used for any windows server where the necessary data is shared on the network, or any linux server where the data is shared over samba. I have a number of these shell scripts, all of which connect to different servers and save their vital data.
Second, onto backing up our client machines which are all running windows XP. We’ve ‘trained’ all our users to store their important documents inside the ‘My Documents’ folder. I then have samba shares on the backup server for each user, and re-map their ‘My Documents’ folder to the network drive. To achieve this, I map the drive on their machine, and then right click on ‘My Documents’, and change the location it points to.
To backup these folders, all I need to do is create a tar archive of each of the samba shares.
Finally, backing up the linux servers. As I said above, some of these are backed up by just making a tar archive of their samba shares. For servers which don’t have samba shares, I run cron jobs on each machine which creates a local backup and then copies it to the backup server through ftp.
An example of how to back up a standard debian/ubuntu apache install:
tar -zcvf /home/backups/apache_configs.tgz /etc/apache2/* -R
tar -zcvf /home/backups/website_data.tgz /var/www/* -R
An example of how to back up a MySQL server. There are 2 ways to do this. The simple way to back up all data is to make a tar archive of the entire MySQL data directory. This is fine for many small sites but may not be suitable for sites where the data is constantly changing, or the tables are using innodb (innodb doesn’t always backup 100% successfully by simply copying the data files). For a standard debian/ubuntu install, this can be achieved by:
tar -zcvf /home/backups/mysql_data.tgz /var/lib/mysql/* -R
Another method of backing up mysql is to use the ‘mysqldump’ command line utility, which will create a dump of the database as a .sql file, and can be re imported at a later date. This is seen as a more secure backup because the sql files can usually be imported across mysql versions easily, but has the downside of a slower backup, slower restore, and occasionally you will need to manually edit the dump files to get them to reimport properly. A mysqldump can be created by running a command similar to the following:
mysqldump -uUSER -pPASSWORD -hHOST DB_NAME > /home/backups/file.sql
mysqldump -uUSER -pPASSWORD -hHOST ANOTHER_DB_NAME > /home/backups/file2.sql
tar -zcvf /home/backups/databases.tgz /home/backups/*.sql
Backing up a DNS server is also very simple, and can be done in much the same way as the apache backup above, making sure that the directory including the configs, and zonefiles are included in the archive.
Mail servers can be a bit more tricky since they rely on configs for different services which are usually found in different locations. Also, all user email must be backed up. The way I achieve this is to have the shell script create a tar file for all user email, and then manually copy the important configs into a directory before creating a tar file containing them all.
Once you’ve backed up the data for the servers, you will need to move it to the backup server for safe keeping. I usually do this over FTP, by adding something similar to the following to the bottom of the backup shell script:
# FTP to backup server
HOST=’backup_ip’
USER=’backup’
PASS=’password’
cd /home/backups/ftp -n $HOST <<END_SCRIPT
quote USER $USER
quote PASS $PASS
binary
quote CWD backup/SERVER_NAME/
put backup_file.tgz
quit
END_SCRIPT
That’s about all there is to know. It’s all fairly simple to do, but ensures that you have backups of all your important data. If you wish to perform incremental backups then it’s advisable to look into rsync.
Once all of the servers have been backed up, I have a script on the ‘backup server’, which does some tidying up, and copies all of the daily backups to a directory with todays date. This means I can store backups for as long as I wish without accidently overwriting them.
