Using Linux, I have several backup levels. One of them is a periodical sector by sector copy (using dd) of my laptop harddisk to an external USB disk. Yes, I have other backups too, like remote rsync.

This approach (the disk dd) is OK when cloning a HDD with no LVM volumes, since I can plug the external disk anytime and mount the partitions simply mounting /dev/sdb* instead of /dev/sda*. Trivial and handy.

Today I moved ALL my harddisk (including the /boot) to LVM. Everything works fine. I will stress it for a couple of days, and then I will do a sector by sector copy to my external harddisk.

Now I have a problem, I guess.

If in the future I plug the external USB HDD to recover any file, the OS will detect a duplicate LVM configuration, with the same name and the same UUID. Even doing a vgrename (which LVM would be renamed, the internal HDD or the external HDD?), the cloned UUID will not change. Is there any command to change name and UUID? Ideally I would clone the HDD and then change the LVM group name and its UUID, but I don't know how to do it.

Another related issue would be...

In the past I have booted my laptop using the external disk, using the BIOS boot menu and changing GRUB entries manually to boot from /dev/sdb instead of /dev/sda. But now my current GRUB configuration boots directly from a LVM logical volume, something like: set root='(LVM-root)' in my grub.cfg. So... What is going to happen with duplicated volumes?

Any suggestion?

I guess I could repartition my external harddisk and change backup strategy from dd to rsync, but this disk has windows installed too, and I really would like to have a physical "real" copy.