Restoring Linux user accounts (just the accounts, not data)

[Robert Heller]

At Wed, 23 Jun 2021 05:03:13 +1000 kauer at biplane.com.au, "Ubuntu user technical support,? not for general discussions" <ubuntu-users at lists.ubuntu.com> wrote:

> 
> On Tue, 2021-06-22 at 14:32 -0400, Robert Heller wrote:
> > Yes, but make sure there are no duplicate UIDs and GIDs.  You will
> > also need to update /etc/group as well.
> 
> I did mention that in my OP. The single necessary group will already
> exist by the time any import happens (but the import process will check
> it's there to make sure). The "-g" option with useradd makes sure that
> all VPN users go into the "openvpn" group and do not get their own
> individual groups. Any admins will always be added manually (or by the
> server creation automation, way ahead of any import).
> 
> > You may also need information from /etc/group.  If each user is in
> > their own group, you will need those lines from /etc/group
> 
> For my purposes, I don't need to worry about groups. However, for the
> general case of restoring Unix accounts this is a very important point.
> And you suggest a neat way of doing it, too :-)

There are a collection of other "common" group memberships, which might not 
matter on a server, but commonly matter on desktops:

cdrom (to mount CDs and DVDs) and plugdev (used for plugable devices)
dialout (user for serial ports).

On little ARM SBCs:

gpio, spi, i2c -- to access the GPIO, SPI, and I2C pins typically available on 
the I/O headers.

Again, for your use case, not something to worry about, but if someone were 
replicating users across a pile of Raspberry Pis or BeagleBones, this is 
something to consider.



> 
> Regards, K.
> 

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