tar backup ignore files

[Colin Watson]

On Sat, Jun 27, 2020 at 10:32:23PM -0600, Gary Aitken wrote:
> On 6/26/20 10:47 AM, Colin Watson wrote:
> > I'd suggest using --one-file-system rather than most of these, and
> > then backing up each file system that you actually want to back up
> > separately.
> 
> Thanks, I was wondering about that...
> This system has only one file system listed in /etc/fstab, but it's unclear to
> me if that constitutes "one file system" when there are entries in /var/lib/lxcfs.

/etc/fstab is not where you want to be looking for this, because virtual
file systems generally aren't listed there.  Try "df" or "mount"
instead.

> On 6/26/20 12:12 PM, Sheemon Lists wrote:
> > /dev:  I did
> > have an opportunity to count my blessings for backing up /dev.  Yes,
> > there is little there [aside from mirror backup of filesystems -
> > another subject], but if a crash is bad enough, /dev will contain the
> > actual map of your devices at the time of the crash. MAKEDEV, which
> > used to be the first object "put" in /dev contains what some
> > programmers meant to be in /dev, not what should be there, definitely
> > not what was there. But I am just an old paranoid, who knows very
> > little.
> 
> Can I ask how you restored that system if /dev was hosed?  Were there
> just things missing that are not "core" devs, so restoring them was only
> needed for some apps to work?

I can perhaps see the utility in having a reference copy of /dev in some
cases, but since /dev is maintained automatically by udev you really
shouldn't ever attempt to restore from such a backup: if you're lucky it
will have no effect, and if not it could cause things to go very badly
wrong.  At most, a reference copy of /dev might be something that you
could use to track down certain kinds of problems after a full system
restore.

-- 
Colin Watson (he/him)                              [cjwatson at ubuntu.com]