Ubuntu Server + Tarball
Ok to sound like a complete moron for about this whole thread.
I've been working on my final for school and it happens to handle disaster recovery and roll-backs
Well I wanted to do backups using Tarball. However I'm not sure how much strain that would put onto a server.
I remember being told a long time ago that you could continuously tar your server to an External Harddrive. Although from everything I've read that doesn't sound right. It works more like any other back up plan you run it during network down time.
Ok so the question here is how does tarball actually function. Being told one thing and reading another is confusing, a professional's point of view would better assist my dilemma.
And yes I have looked at some guides online even the one within Ubuntu's documentation
P.S. Don't want to write a paragraph on Tarball and end up being completely wrong.
Well, we aren't supposed to help with school assignments. That said, you can use tar. There are several levels of backup. One would be a bit-image of a drive for disaster recovery (I make such, using dd, every couple of weeks). Another would be to capture changed files using rsync to copy the change sets to another system/drive. Tar can also be used for that, but rsync is more commonly used for these purposes.
Oh ok. So I could just do one full backup after completing the network setup and then just use Rsync to backup any files that have changed each day.
I wouldnt mix two programs here.
It adds complexity with little gain, because for a restore you would need to untar first and then rsync, hoping that e.g. rsync is happy with the timestamps.
That said, you can also do incrementals with tar
GNU tar 1.26: 5.2 Using tar to Perform Incremental Dumps
(Slightly OT: )
Or use the extra logic of rsnapshot , which is built on rsync.
Or go old school with dump and restore.
Or implement a full featured backup suite such as Bacula
Thank You Irithori
That link was actually exactly something I was trying to find.
So I can use Tarball to do an entire dump once a week or once a month then use the incremental once a week and be completely set for backups.
I wanted to just use Tar because it's simple and all Linux comes with it...normally lol.
I only have one main concern with Tar however. But as seeing as I do not need a full indepth explanation I should be fine with what I have.
(My other Concern)
Tar can be used to write to anywhere on the network correct?
Or would I have to mount a drive on the Server for it to use Tar to write to that drive? (i.e. A firewall protected computer in a DMZ opposed to say an External hooked directly into the server?)
I just learned, that tar can indeed output to a remote server.
Thank you :)
There is the -f [user@][hostname:]file option.
If user/hostname are given, then tar will try to connect to a rsh server on <hostname>.
rsh is no longer used, because it is in most cases overshadowed by the (much) more secure and versatile ssh.
But if you intend to -and the network is fairly isolated and/or not important- then you could set up a rsh server and utilize this remote feature of tar.
Traditionally, tar is used to write to a tapedrive but can also output to a file.
This file can be on a local filesystem such as ext3/4, xfs, etc but also network filesystems like nfs and even cifs (the latter introduces additional complexity as it is meant as a windows/unix bridge)
Howto: Use tar Command Through Network Over SSH Session
Google......for the win I suppose but according to this you can use it over an SSH session. lol you can drop it on a remote Tape drive or a remote computer.
Imho: All fine and good for a one shot action.
But I wouldnt advise this as a long term solution.
Because this oneliner doesnt do any errorhandling, cant deal with network hickups, there is no guarding against concurrent use from multiple clients, etc.
For a backup of a whole network of clients, you definitely need something more sophisticated like bacula or amanda.
Tar will also happily write to a file on a network share, such as NFS or CIFS/Samba.
Although kind of funny you mentioned that.
A student in my class was referring to an MS backup method and failed to mention that the method no longer wrote to tape drives and to do so you had to mount the tape drive as a shared resource then select it as a file.
Funny part was my teacher nor any of the students say a problem with sharing a tape drive on a network as a storage device. Would raise quite a few concerns if people accidentally write to it.