Restoring backups and effect on GRUB

[Colin Watson]

On Mon, Aug 05, 2019 at 06:00:50PM -0400, Rashkae wrote:
> One important thing to keep in mind, to get a full copy of your root
> filesystem, you must re-mount it somewhere else.  It might seem
> reckless, but in Linux, you *can* mount filesystems twice.  So, for
> example, your rout filesystem is on /dev/sda2
> 
> mkdir /mnt/sda2
> mount /dev/sda2 /mnt/sda2
> 
> Now you can back up the contents of the /mnt/sda2
> 
> The reason for this is that the root filesystem has many files, like
> devices nodes under /dev that will not get backed up from / because they
> are covered by udev mounted at /mnt.  There used to be some stuff in
> /proc or /sys, I forget but that that seems to be gone now.

For the record, none of the stuff that's overmounted in that way can
possibly have been relevant to anything for quite a few years; the
initramfs mounts /dev (etc.) over the top before anything would see
them.

In this case I think you're remembering something that might have once
been necessary a very long time ago, but there's no need to perpetuate
it these days.

-- 
Colin Watson                                       [cjwatson at ubuntu.com]