Upgrade CentOS 7 to 8 Webmin Server

Hi Everyone,
sorry if this has been asked before… I could not find much so wanted to ask here. I have a 2 years old AWS EC2 sever running Webmin/Virtualmin on CentOS 7. It is having a lot of email accounts for a domain as well as PostgresSQL.

CentOS7 is quite old now and installing everything/anything required hacking into custom repos and stuff if you want a relatively newer version of it. So I was thinking if it is fine to upgrade a CentOS7 webmin server to CentOS8

I would like to have a real use case experience and not just hypothetical one from someone who had hand on with this, what pitfalls they faced so that I can have my heads up before hand.

Disclaimer… I’m a Debian guy from 10+ years (Slackware before it) and never really touched CentOS/Redhat. This is one of my new client’s server who recently contracted me.

Please pour in your reviews and ideas.
Many thanks

I have a similar situation - moving from Ubuntu 16 to 18.

My thoughts are to

  • bring up a new server,
  • install\configure what I need
  • recreate the Virtual Servers\Domains,
  • copy the public_html folders,
  • recreate email accounts etc.,
  • use a command line program (can’t remember the name but it’s on my laptop) which copies IMAP mailboxes from one server to another
  • switch the DNS records to point all Virtual Server domains to the new server’s IP.

HIH

Dibs

I agree, thus far…

Virtualmin’s restore offers you the option of enabling specific configuration options from a full backup. You could get the web content and user accounts with passwords migrated over to the new server selectively, keeping away from the restore process other stuff you don’t want copied over.

Imapsync is your friend.

Didn’t realise the restore process could be selective. Many thanks on that info - good to know.

I used IMAPCopy previously.

Many Thanks

Dibs

I need to do this with a debian 9 system.
Trouble is, i dont host dns for domains on my server…so i need to keep same static ipaddress.

Is it possible to do a virtualmin migration for web and mail from debian 9 to debian 10 and after a little downtime, shut down the old server and swap its ip address to the new one?

You are a man with a plan. Go for it.

So you think my idea is a workable idea calport?
Will the virtualmin migration also move all my client domains IMAP and pop3 emails across too?
Email is my biggest worry already had one catastrophe with email a few weeks back…client lost 1 days worth of email amd they were not happy Cant run that risk again.

Indeed, it is.

The selective restore method that I discussed with @Dibs is one way to upgrade / migrate where @Dibs is aware of downtime that his particular approach entails. If you want just ‘a little’ downtime @adamjedgar (while IPs swap) then the workflow must be different from @Dibs’.

The migration must be planned accordingly. I suggest you start a new topic as this one deals with CentOS upgrade.

Over all I think Virtualmin is doing well on CentOS 8. But easy for me to say since I usually start from scratch, not to mention I’m not responsible for anyone’s email but my own. For a production situation definitely follow the migration advice you’re getting. My only advice is to consider your comfort zone before upgrading. CentOS 7 may be showing its age but I doubt you’ll see a lot of difference with CentOS 8 in quality of service. I read that Red Hat tried to make the transition from RHEL 7 to 8 less traumatic than 6 to 7 turned out.

Me and CentOS go way back but I’m new to Webmin/Virtualmin and I’m mostly trial running. My first CentOS 8 installation had a lot of problems. For my second attempt the following post was very informative, particularly in regard to suexec, and especially how to avert a few common problems.

With CentOS 8 you’re likely to run into obstacles that evolve into delays that wouldn’t occur on a refined distro like CentOS 7. For example, because of some Red Hat bureaucracy, installing something as innocuous as whois on CentOS 8 involved extra time and effort when normally it comes straight from the EPEL repo using ‘yum install whois’. Here’s the lowdown on that:

https://forums.centos.org/viewtopic.php?f=54&p=313836

Webmin offers a way to install packages but I installed whois this way (install both packages):

dnf install https://archive.fedoraproject.org/pub/archive/epel/8.1/Everything/x86_64/Packages/w/whois-nls-5.5.1-1.el8.noarch.rpm

dnf install https://archive.fedoraproject.org/pub/archive/epel/8.1/Everything/x86_64/Packages/w/whois-5.5.1-1.el8.x86_64.rpm

I’m seeing other unusual issues with package installations that I’m still learning about. For instance, with CentOS 8 I’m noticing more source src.rpm packages in addition to binary rpm packages, and certain source packages don’t seem to build correctly or are incomplete in some way. One example I experienced is the Redis 5 package from the AppSream repo, which ultimately worked out but only because of manual intervention that was never necessary on CentOS 7.

There were other installation headaches that I’ll probably bring up in separate posts. So far everything came out in the wash and Webmin/Virtualmin seems happy on CentOS 8.

Hope this offers some perspective.

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when using virtualmin to migrate, the o/s is irrelevant…virtualmin is performing the task itself. I am already familiar with moving domains, however, my questions are related to whether or not virtualmin can also move emails in the migration process? Some of what i have seen in the backend thus far give me the impression it may not move emails too?

Is it really?

Yes, Virtialmin can ‘move email’ as part of the full restore process. And also selectively restore only users / email accounts, passwords and all email in each account, if just the following options are enabled:

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