How to backup debian system?

Question

I have VPS hosting with debian operating system.

I would like to backup whole system time by time.

Here is a lot of questions how to backup OS on local machine, but it's not what I need. I have just ssh and superuser account.

Answer 1

If you need to backup just the system configuration (which at the end of the day usually is about third of the content of a system), all you should need is a list of packages installed + their configuration. The list of installed packages you can get with your packaging utility, the system-wide configuration lives in /etc (in /usr/local/etc and /opt/<vendor>/etc if you have some really non-standard stuff installed) and you might also want to throw in /root. Hence you can just backup the configuration directories and the list of installed packages and you should have everything needed (for the first third).

The other two thirds would be:

• private user data (home directories), and

• public user data: data accessed by various services running on the system - usually mail queues, data served by http daemon. In some sense virtual machines or change-roots could fall into this category as well.

Regarding the system-wide back-up, apart from options mentioned in the other answers, if your installation (be it a virtualised guest or the VPS host) lives on a separate filesystem, you can either use the filesystem's native backup/snapshot capability (e.g. XFS has this feature) or mount it read-only and dump its containing device (which might be dangerous though). Plain ssh would be more enough to do this.

As with any other low-level system operation, running any the operation in terminal multiplexer, which protects the backup process from possible connection drops, and having a spare ssh connection (preferably served by a different process) is recommendable.

Answer 2

I'm using rsync for file backup. In the /etc/cron.daily put a script like:

EXCLUDES=/etc/rsync/excludes.txt
TARGETDIR=root@::backup-target
BACKUPDIR=/`date +%Y%m%d-%H%M%S`
export RSYNC_PASSWORD="veryverysecret"

rsync --force --ignore-errors --delete-excluded --exclude-from=${EXCLUDES} --delete --backup --backup-dir=${BACKUPDIR} -a -H -X -A / ${TARGETDIR}/current

Of course you have to configure the host-where-to-store-backup. Have a look in the rsyncd.conf man page.

Answer 3

I personally use Dirvish.org It is a disk based file backup that uses rsync over ssh and it is in Ubuntu repositories (so quite likely in Debian's too).

It is easy to configure, does incremental backups to disk, uses encryption to communicate accross the network, expiring old images is simple, only copies changed files, ...