move users and groups from one linux box to another

I just typed pwunconv and grpunconv to move my users from my one sendmail server to another, but it has now blocked my root user from assiging passwords to any users. Root can still access the box, but cannot chage passowrds and gives message " passwd: User not known to the underlying authentication module" Please help me reseeting root previliges and please tell me ow do I migrate users and groups from one box to another. thanks.Sadiq
msl110Asked:
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liddlerCommented:
Sadiq,
I have seen similar problems when using a much stricter /etc/pam.conf.  Can you compare the pam.conf on the two machines?
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msl110Author Commented:
i have not made the other machine ready yet , but tell me how do i allow root on the first machine to have its old rights back, its now saying User not known to the underlying authentication module" for root, please how do I reset  pwunconv and grpunconv

thanks
Sadiq
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jlevieCommented:
It may be the missing shadow file that's the problem. I'd try running pwconv & grpconv to convert back to standard forms and see if that fixes it.

FYI: You don't need to convert from passwd/shadow, group/gshadow to move users to another Linux system. You can merge data from the existing files into their corresponding file on the new server with an editor.
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msl110Author Commented:
thanks guys, i searched and typed pwconv and grpconv and I was back on defualt and root was fine again. thanks. Now I just need to know how do I migrate my users fomr RedHat 7.3 server , users groups and home directories to RedHat 9 Server. Is there a migration tool. I copied the passwd file and the shadow file but when i log on with the nes username it goes to the bash login. Can anoyone please help, I have more than 100 sendmail users and now I need to go on to RedHat9. thanks

Sadiq
 
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msl110Author Commented:
<You can merge data from the existing files into their corresponding file on the new server with an editor.>

Please advise me which files to edit and merge, if I want all users , home directories and groups too. thanks

 
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jlevieCommented:
The files that need to be merged are (all in /etc) passwd, shadow, group, and gshadow. By merging I mean that you'll copy the files from the 7.3 server to your 9 system, changing the names to, say passwd.old, shadow.old, etc. Then with a text editor you'll paste the user lines from the old files into the corresponding RH 9 file, skipping the system accounts. Be careful with passwd & shadow. There needs to be a line for line correspondence between usernames in passwd and in shadow. Don't copy the files from 7.3 over the RH 9 files. There are differences in the system accounts.

You'll also have to copy, preserving ownership and permissions, the user directories from your 7.3 system to the new server. This most easily done by tar'ing /home on 7.3 and unpacking it on 9. If NFS is enabled on the 7.3 system and /home is exported the process would look like:

--on the RH 9 server--
mkdir /mnt/nfs
mount 7.3-server:/home /mnt/nfs
cd /mnt/nfs
tar cf - . | (cd /home; tar xvpf -)
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msl110Author Commented:
thanks jlevie,

Brilliant , absolutely brilliant. thanks!!!! Sadiq
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