Notes: Migrate Linux users to another Linux server
The Problem
I have a Debian 5.0.4 virtual machine that's no longer supported and my shop is pretty much a CentOS ecosystem. The server is primary use for sFTP with over 250 user accounts.
The PLAN: Migrate from Debain 5 to CentOS7, and avoid manually recreating user accounts or generating new passwords. Sounds easy right? Actually, it was and wasn’t as time consuming as I anticipated or took a lot effort to get all the user accounts including the host directory over to the new server.
I outlined the steps in gist below:
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| #Setup UID filter limit | |
| export UGIDLIMIT=500 | |
| #copy /etc/passwd accounts to /opt/move/passwd.mig using awk to filter out system account | |
| awk -v LIMIT=$UGIDLIMIT -F: '($3>=LIMIT) && ($3!=65534)' /etc/passwd > /opt/move/passwd.mig | |
| awk -v LIMIT=$UGIDLIMIT -F: '($3>=LIMIT) && ($3!=65534)' /etc/group > /opt/move/group.mig | |
| awk -v LIMIT=$UGIDLIMIT -F: '($3>=LIMIT) && ($3!=65534) {print $1}' /etc/passwd \ | |
| | tee - |egrep -f - /etc/shadow > /opt/move/shadow.mig | |
| cp /etc/gshadow /opt/move/gshadow.mig | |
| # | |
| scp -r /opt/move/* [email protected]:/path/to/location | |
| mkdir /root/newsusers.bak | |
| cp /etc/passwd /etc/shadow /etc/group /etc/gshadow /root/newsusers.bak | |
| cd /path/to/location | |
| cat passwd.mig >> /etc/passwd | |
| cat group.mig >> /etc/group | |
| cat shadow.mig >> /etc/shadow | |
| /bin/cp gshadow.mig /etc/gshadow | |
| #move home directory over ssh (tar to preserve ownership and permissions) | |
| ssh [email protected] "tar czvpf - /home" | tar xzpf - -C / | |
FYI: Linux is awesome! :D