Howto: Backup and restore your system!

[traxtar3]

quick question..

i have my /home on a seperate partition, when i do the backup i want to exclude it. my question is when i restore it, will it screw with anything in the /home dir?

[xfile087]

quick question..

i have my /home on a seperate partition, when i do the backup i want to exclude it. my question is when i restore it, will it screw with anything in the /home dir?

If you exclude /home in your backup then when you restore it, it shouldn't touch it at all. I do this myself and it works a treat, plus it's quicker to backup!

[BassKozz]

Would it be better to use 7z (p7zip) to do this (rather then using tar)?
This "should" create a smaller backup archive file... correct?

[herger]

Hi all!
The advice to use a tar.gz or tar.bz2 to restore your system is WRONG!!!
DON'T TRUST THIS METHOD!!!!
I followed the instructions and obtained a 4 Gb tar.bz2 file.
My laptop crashed when I tried to configure virtualbox (another bad chance) and I tired to restore my system by extracting the backup.tar.bz2 as explained at the beginning of the thread.
Result: it failed in extracting such a huge file and I had to reinstall everything from the beginning.
Pay attention: DON'T TRUST THE "tar" METHOD TO RESTORE YOUR SYSTEM!!!
I think I will do an image of my hd and keep it very carefully on a separate hd.........
Your depserate

H

[erginemr]

Would it be better to use 7z (p7zip) to do this (rather then using tar)?
This "should" create a smaller backup archive file... correct?

As far as I know, 7-zip does not preserve file owner and permissions information, which is crucial for a successful restore, and therefore, cannot be used as a replacement to tar:
http://www.ohloh.net/projects/3769/reviews

[erginemr]

Hi all!
The advice to use a tar.gz or tar.bz2 to restore your system is WRONG!!!
DON'T TRUST THIS METHOD!!!!
I followed the instructions and obtained a 4 Gb tar.bz2 file.
My laptop crashed when I tried to configure virtualbox (another bad chance) and I tired to restore my system by extracting the backup.tar.bz2 as explained at the beginning of the thread.
Result: it failed in extracting such a huge file and I had to reinstall everything from the beginning.
Pay attention: DON'T TRUST THE "tar" METHOD TO RESTORE YOUR SYSTEM!!!
I think I will do an image of my hd and keep it very carefully on a separate hd.........
Your depserate

H

This is a very interesting phenomenon. Thank you very much for pointing out the file size limit problem for the uninformed Ubuntu user.

I have googled for a while on this problem and have found these:

1. http://answers.google.com/answers/threadview?id=25116
This page asserts that, depending on the file system used, there is no limit to the maximum file size in "tar". Note also the last user comment therein.

2. http://www.codecomments.com/archive3...11-691598.html
This page draws the attention to "gzip" (and also possibly "bz2"), which has a size limit of 2 GB, due to the nature of a "zip" file.

3. http://aplawrence.com/Bofcusm/2078.html
This page suggests using "pipes" to extract the tar file from a large-scale gzip / bz2 file, as a promising workaround to the problem.

[El_Belgicano]

Hi all!
The advice to use a tar.gz or tar.bz2 to restore your system is WRONG!!!
DON'T TRUST THIS METHOD!!!!
I followed the instructions and obtained a 4 Gb tar.bz2 file.
My laptop crashed when I tried to configure virtualbox (another bad chance) and I tired to restore my system by extracting the backup.tar.bz2 as explained at the beginning of the thread.
Result: it failed in extracting such a huge file and I had to reinstall everything from the beginning.
Pay attention: DON'T TRUST THE "tar" METHOD TO RESTORE YOUR SYSTEM!!!
I think I will do an image of my hd and keep it very carefully on a separate hd.........
Your depserate

H

Maybe you did something wrong, it work perfectly for me, except some minor problems that were solved within 5 minutes ...

1) tar backup:

sudo tar cvpzf /wheretobackup/backup.tgz --exclude=/etc/fstab --exclude=/tmp --exclude=/boot --exclude=/proc --exclude=/lost+found --exclude=/media --exclude=/mnt --exclude=/sys /

2) bad things happens to my installation making it unusable
3) fresh install with 7.10 CD
4) untar the whole archive
5) fix these minor problems

total time to be back up and running: 90 minutes or something like that.
archive was about 4.5 gigs...

[BassKozz]

As far as I know, 7-zip does not preserve file owner and permissions information, which is crucial for a successful restore, and therefore, cannot be used as a replacement to tar:
http://www.ohloh.net/projects/3769/reviews

Bummer
You think the guys who work on the 7z archive format might add this feature?

[PJL]

Hi,

I've just had an experience similar to Nightwalker07 in post #393 when unpacking a tarred backup of my ubuntu 7.10 server. The responses from tech9 about excluding /boot fixed the problem - hooray! (I figured out that I could save a copy of the /boot from the fresh installation somewhere else before unpacking the tar file and then overwriting the /boot with the saved copy. Using --exclude at the unpacking stage didn't seem to work)

However, my question is: Can someone edit the original post to add the requirement to exclude /boot from the tar file? This could save people like me a lot of hassle - I know I was lazy for not reading all fifty-odd pages of the thread in the first place, and I know that tech9 has subsequently started a new thread on the topic, but *this* is the thread that came up when I searched the topic, and it has the appearance of being definitive so to be hit with a problem at the restoring stage was a bit of a pain (fortunately it happened at a non-critical time though).

I would also just like to say that these forums ROCK! Thanks to everyone for contributing and helping me to learn so much.

[neverliveneverdie]

Ok I think you're right. I'll edit the howto.
But if you just recreate the dev directory after restoring, does the system automatically recreate the device nodes?
Somehow I don't think i've ever had the problem you discribe. My backups have always been somewhat proportional to the amount of data that was actually on the disk; I didn't have it suddenly double in size or anything. But if Linux just recreates the device nodes by itself then I guess it is save to exclude 'dev'.

Hi i checked to see if it recreated the device nodes and it did infact recreate them on the boot.