[K12OSN] restore backup with chroot + grub-install
Robert Arkiletian
robark at telus.net
Tue Dec 14 04:10:14 UTC 2004
Les Mikesell wrote:
>On Sat, 2004-12-11 at 22:12, Robert Arkiletian wrote:
>
>
>>
>>dd if=/dev/sda1 of=/dev/hdb1
>>
>>
>
>If you don't take the whole disk image to preserve the boot,
>partition, and label info, you might as well use a file
>based copy technique. 'cp -a' will work, or if you are
>doing it repeatedly to stay up to date you can do:
> rysnc --delete --one-file-system -avH source_dir dest_dir
>where the source/dest are the mount points of the partitions.
>
>
>
I agree the file based copy is more versatile but would it not be
possible to just copy the partition, as above, and then copy the first
446 bytes of the MBR to the backup drive MBR.
So during restore you could fdisk the new drive EXACTLY like the source
then dd over the / partition and also the first 446 bytes of the backup
drive. I haven't tried it but it sounds logical to me. So fdisk would
write bytes 446-512. You would also have to mkswap, as you mentioned
earlier, on any swap partitions.
------------
Also, any difference between tar and cp -a? I looked at man cp and it says
-a, --archive
Preserve as much as possible of the structure and
attributes of the original files in the copy (but
do not preserve directory structure). Equivalent
to -dpPR.
Apart from the fact that tar can compress. I'm guessing tar is better at
rebuilding the "structure" of the filesystem. Whatever that means.
As for rsync. I don't think I will use it. I know it's faster but since
I have a huge backup drive I don't mind taking snapshots with tar. That
way if I do a backup without noticing that the drive has begun to die, I
can always restore a previous (known good) backup.
--
Robert Arkiletian
C++ GUI tutorial http://fltk.org/links.php?V219
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