Backup Theory - newbie guidance request
Short-term Objective: make it so that I can thrash about on Linode while I learn LAMP - firewalls - ssh tunnels etc… safe in the knowledge I can fix screw ups in a couple of minutes
Shortly After Short-term Objective: put some production sites on the regularly backed up Linode
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Questions -
1) I seem to be able to create multiple Configuration Profiles in my Linode - is it a) possible - b) advisable - to create 2 Configuration Profiles with 1 regularly backing up to the other? (what happens to IP addresses etc if there are 2 instances running at the same time? Can you specify which Configuration Profile the Ajax console logs in to if there's more than one Configuration running at the same time?
1.1) I see there is a way to create a duplicate disk image in the Linode console - would it make sense or even be possible to create regular duplicates of this in production? (I suspect not - but I just don't know)
1.1.1) How do you restore from a disk image? I'm scared to delete my current working Configuration Profile to find out!
2) Is Rdiff-Backup the tool to do this? If what I understand from other posts is correct - this tool is widely used and a step higher than Rsync in complexity allowing scheduled incremental change backups etc. How does this option compare with the Bacula module that comes pre-packed in Webmin? I'm asking this becasue I don't want to become a backup expert that understands lots of tools - I'd like just one useful one (& preferably easy) to learn and move forward with.
3) Restore theory - if something goes pear-shaped with an install and I have a backup - from Rdiff-backup (for example) - would I then completely wipe the Configuration Profile and create a new one with a brand new Linux distro install and then import the backup into it? Or is the backup something you send to a completely blank Configuration Profile?
Thanks in advance for any guidance here
Duncan
3 Replies
1.1) If you have space to spare, duplicating a disk image might be the easiest way to back up your whole server. But you must shut down your server before duplicating, otherwise you might get a corrupt copy because some files get changed halfway through the duplication process.
1.1.1) You don't "restore" a disk image; you just detach the ones you don't need and attach the ones you want. You can choose which disk image(s) to attach by editing the appropriate configuration profile.
2) Not if you're thinking about doing this using duplicate disk images. In order to use rsync/rdiff-backup you need to have both the production server and the backup server online at the same time, which is only possible if you have two linodes or else you back up to your home computer.
Rdiff-backup is more featureful than bare rsync. But if you want simplicity, rsnapshot is also a very useful tool. Don't know about Bacula, never used it
3) The method of restoration depends on the method of backup. If you backup using duplicate disk images, you just attach the right image and reboot. If you use an rsync derivative, yes you'll need to copy everything back to where they were.
Personally I don't backup "everything" on the server; I just backup my data (/home), server logs (/var/log), and some important configuration files here and there (mostly under /etc). Because I keep a list of all the packages that are installed on my production box (php5, mysql, etc), I can start with a new distro, install all the necessary packages in one go, and then only restore the necessary files. Only takes 20 minutes to have everything ready to go!
But there are other threads that discuss exactly what is necessary, so be sure to look them up.
OK - the disk image option looks good for the short term while I'm messing around and maybe rsnapshot for the next stage..
Cheers
