[Grml] /dev, udev and backup

[Michael Prokop]

* T o n g <mlist4suntong at yahoo.com> [20080712 07:05]:
> On Fri, 11 Jul 2008 22:15:57 +0200, Michael Prokop wrote:

> > Well, static devices can be found in /dev/.static/dev
> > and if configured/used also in /lib/udev/devices.

> > What's really important are the null, zero, console and tty[0-9]
> > devices which are all easy to generate/restore using MAKEDEV in case
> > you lose them.

> Thanks for the explanation mika. I was hoping that I can just backup those
> static devices, but I found both my /dev/.static/dev/ & /lib/udev/devices/
> are empty. If I duplicate null, zero, console and tty[0-9] devices into
> /dev/.static/dev/ and back them up, would it works?

Just executing MAKEDEV will provide null, zero & CO for you.
No need to copy them to /dev/.static/dev, though I'm wondering why
your /dev/.static/dev/ is empty. Are you listing the content of the
directory as user root ("ls -la /dev/.static/dev/")?

> > So basically it's not necessary to backup /dev as long as you know
> > how to recover it ;) - but as /dev is usually less than 1MB size it
> > won't hurt to place it in your backups as well. ;)

> Yeah, 1MB is not that big. My worry was the portability. If I backup all
> devices in PC A, then restore them on PC B, what would happen?

Relevant are the core devices (as mentioned above) and the device
for your rootfs ("mount | grep 'on / '"), the rest will be handled
by udev and its tmpfs. If you just backup whole /dev you should be
on the safe side.

regards,
-mika-
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