[CentOS] Managing users and passwords

Thu Mar 24 16:16:36 UTC 2011
Todd Cary <todd at aristesoftware.com>

On 3/24/2011 8:04 AM, Les Mikesell wrote:
> On 3/23/2011 10:45 PM, Todd Cary wrote:
>> I plan to make my current Centos 4 HD a slave and install Centos
>> 5.5 on a new HD (master).  Then comes the challenge of of moving
>> all of my /home/"user" data to the new master.  I have some
>> preliminary questions:
>> Is this a good strategy for installing Centos 5.5: keep the
>> Centos 4 on a slave disk?
> It's a reasonable approach if you only have one computer.  Just pick the
> new 1st drive only (and remember your old one is already on the 2nd
> controller) in the installer.
>> Will the Centos 5.5 detect the slave disk (Centos 4)?
> It will see it at the hardware level but not do anything with it. You'll
> need to figure out the device name or label for the partition (and
> Centos5 will probably call it /dev/sd? instead of hd) and mount it
> somewhere.  You should also be able to configure a dual boot if you wanted.
For now, the Centos 4 disk is disconnected...playing it safe.  
Later I'll activate the HD as a slave.
>> Is there a way to move the users, groups and passwords from one
>> disk to the new Centos 5.5?
> The files /etc/passwd, /etc/shadow, /etc/group, and /etc/gshadow have
> this information.  But don't just copy them over.  The accounts below
> uid 500 belong to the system and may be different between versions or
> depending on the installed software.  You can edit your old entries that
> you have added into the new corresponding files.  Or, for a small number
> of users, just 'adduser -u uid login_name', then 'passwd login_name' to
> set the password.

Actually, there are less than 12 users, as I recall, so manually 
setting them up will be the easiest.

>> IT departments must have servers go down or want to install a new
>> version of Linux and have the same challenges.
> Normally if there are enough machines/users for this to be a problem,
> there would be a central authentication mechanism like LDAP or active
> directory set up.  Servers for things other than direct login or file
> mapping often don't have many real users, though.

Yes, that makes sense.  Of course, what happens if there is a 
need to bring up a new box for the authentication?



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