Upgading CentOS 6.6 to 7


OK, so I looked at https://www.virtualmin.com/documentation/system/migrate and read a number of threads that seem to say that document may be incomplete or the tools might be short, although some of those threads seem quite dated.

So, just looking for a sanity check:

I have a virtualmin/cloudmin/webmin system. Platform is CentOS 6.6 (Final). I want to upgrade it to Centos 7. My question is, would this procedure work (for me a couple of hours of downtime is alright, we have hard outage maintenance windows):

  1. Follow the instructions from above link, dumping the backups to a spare hard drive.
  2. Power off system
  3. Install new hard drives (for ease of rollback, drives are pretty cheap comparatively)
  4. Power up system
  5. Install new Centos 7 using minimal install ISO, configure with same primary IPV4 and IPV6 addresses as old system
  6. Install webmin/virtualmin/cloudmin with automated installer script
  7. Restore backups from spare hard drive
    8 Have all servers up with same IPs and settings from Centos 6.6 system on new Centos 7 system?

It seems like it should, however some previous posts seem to indicate it might not be quite that simple?

Thanks in advance,


That migration doc is current and does work well.

However, migrating to a new server is always a big deal, and there can be problems involved when moving to a new distro/server.

With that in mind, we’d highly recommend testing the process first to see what all is involved, and to get an understanding of how long it will take.

For example, you could install CentOS 7 into a VirtualBox instance, install Virtualmin onto that, and then import your domains into it.

Then, access your various websites, and see if there are any problems.

There could be dependencies that need ot be installed, PHP config tweaks that need to be made, or other things that you’d want to be aware of while you’re not under the gun of a maintenance window.

Once you’ve gotten the whole process down, and are confident that it’s working as you need, then you could perform the actual migration.

We normally wouldn’t recommend performing the install onto your existing server, but knowing that you can just install the old drives does make that seem a bit safer :slight_smile: