dump and restore

I’ve heard many people talk about backups via dump and restore. I’ve never really tried it, although it looks like I should have been using it all along.

I am rebuilding my firewall, which is based on a WRAP 1C-2 [sbc]{tag/sbc}. I want to use two such boxes, one to connect to my two ISPs (both cheap) and the other to create a DMZ network.

I just finished building one of them (similar as the steps in [this article]{sbc-bootstrap-with-debian}). Now I want to clone the image, because the systems will be almost identical. So I stick in the CF card into my card reader, and run

    # sudo mount /dev/sdc1 /mnt/flash1
    # sudo dump -0f - /mnt/flash1/ | pv -Wbr | bzip2 -9 > /tmp/wrap2-`ymd-hms`.dump.bz2

This creates a wrap2-20061228-220157.dump.bz2 file. I noticed that it was much smaller then the bzip2’ed dd-dump I usually would have ran. That’s a plus.

Now to restore, I remove the original, put in a new CF card, and run:

    # sudo mount /dev/sdc1 /mnt/flash1
    # cd /mnt/flash1
    # bunzip2 < /tmp/wrap2-20061228-220157.dump.bz2 | pv -Wbr | sudo restore rf -

Note that this is potentially dangerous. Make sure you switch to the right directory first, and that it contains the file-system you want to overwrite. Look at the restore man page.

I’ve used this page as reference. It happens to show how to clone a disk using various methods.