Moving my linux server to the cloud

After more than 10 years and after a thorough re-calculation of my family’s TCO on internet and server infrastructure, we came to the conclusion that it would be more economic to move the physical server and the associated leased line and IP subnet to a more modern cloud based infrastructure. (OK, I admit… It was actually way more spontaneous than it sounds… But I always wanted to say “TCO” in a blog post. 😉 )

Anyway – I had to

  1. find a cloud provider I trust
  2. relocate the server, services and data with as little downtime as possible

Luckily, my internet provider (iWay.ch) also offers virtual machines on a cloud based infrastructure entirely hosted in Switzerland – hello NSA – for a reasonable price. After going through all the contractual negotiations (i.e. click on ‘Agree’ on a web page) I got my cloud console login – like the one you get from Amazon.

I’ve set up an openSuSE 12.2 server from the provided template, ran a distro upgrade to 12.3 and my primary infrastructure was basically up-and-running within less than an hour.

A couple days before the actual migration, I did set the default TTL and refresh values for all my DNS zones to a very low value. This was to compensate the IP address change I had to undertake for my hosted domains. I did the change and pushed the updated zones out in the wild.

The first service I migrated was the DNS server. I “rsync” the relevant directories and then I went to the registrar of my domains and updated my name server IP address. The A records in the zone files still pointing to he old server, obviously. Shortly after I did the IP change, I began to see DNS requests to appear in my new server’s log files.

The next step was to replicate all the customer data (home directories, mail boxes and mysql data files) to the new server. I also chose to do this using rsync over ssh. After I set up the necessary sync jobs, I let it run over night to copy the initial set of data.

The next day I replicated the configuration settings of Apache, Postfix, dovecot and mysql to the new server the same way using rsync.
After some initial testing and tweaking on the new server, I ran the rsync jobs again and then I was finally able to make the switch on my DNS server by altering only 3 lines (A record for MX, A record for www and serial number). I shutdown the services on the old server and bounced the DNS on the new one and less than a minute later the HTTP requests and mail messages began to hit the new server.

At the end, I was a bit surprised how easy the migration went.
I realized that with only little planning and the right set of basic tools, you can get things done quickly – unlike some recent experiences I made at other places…

 

Rolf Klemenz

 

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