Last week, I gave 5 tips to help you migrate your server. One of those tips was creating a plan. Planning is the only way to assure a successful migration.
So what goes into a server migration plan? In this multi-part blog post, I will highlight some things we consider when handling server migrations as part of our server support work. The details of the plan largely depend on the complexity of your environment and goals, but here are a few helpful tips for migrating your dedicated server.
Before you even consider migration, do some housecleaning. Look at your current server and identify any old sites, email accounts, backups or other assets that are no longer required. If you think you will need the data, archive it off of your production server. You want your server to be as lean as possible when you do the migration. By cleaning up your server first, you will have:
- less data to migrate.
- fewer post-migration issues
- faster migration window
Many migration tools built into control panels like Plesk and cPanel allow you to do full server migrations with a few clicks. This is much easier than selecting accounts one at a time.
Inventory Your Server
Once you’ve cleaned up your server, inventorying the contents is easier. If you are running a single site, you may simply know what email accounts and sites are on your system. However, if you are hosting multiple sites and let end users add sub-domains, email accounts or databases, you may not know what exactly is on your system.
Before migrating, take inventory of your server’s domains, email accounts, and databases. Don’t for forget about sub-domains, aliases and other add-on type information. By inventorying your contents, you can:
- confirm that the new server has all of the data
- avoid accounts getting skipped
- assure that DNS is handled properly on all domains
With your inventory in hand, you can then begin to dig into the details of the server migration itself.
DNS Migration Strategy
In my experience, DNS accounts for the majority of migration failures. This is especially true if you are running a shared hosting service or hosting client’s sites. You may not be in control of the registrar information.
If you do not plan for DNS changes, your migration will fail. Before migrating the server, you will need to know:
- the registrar for every site
- the nameserver for every site
- the old and new IP addresses for every site
I recommend making a spreadsheet with this information. If you are using your own nameservers, then flipping their IP address at the registrar is an easy process. However, I’ve seen many failures where server managers have domains registered in different places or their client’s have control of the domain registration information.
Be certain, you can update DNS as required at the right time. Failure to plan for the DNS changes often causes migration delays, service interruptions or even lost data as traffic is split between two systems. I cannot overstress the importance of having a DNS plan when migrating a server.
This is a simple but often overlooked issue. On your new server be sure that you have:
- ample disk space, likely a 30-40% overhead due to how some migration tools work
- sufficient IP addresses
- control panel license to match your domain count
- fast network (100 or 1000Mbit/sec)
I’ve seen many migrations come to a grinding halt due to insufficient IP addresses, lack of disk space or a control panel license issue. These are simple things to check off before you start. You don’t want to hit them in the middle of a migration and have to start over. Also, if you only have a 10Mbit network connection and are trying to move gigabytes of data, it will take hours. A 10Mbit network is only ~ 4GB/hr of data transfer, so even just 20GB of data can take 5 hours or more to transfer.
Well, I am running out of time, so I will need to wrap this up in the next series in the next installment. In my next post on server migration planning, I will cover incorporating testing into your plan, how to deal with clients, and strategies to deal with downtime. If all of this sounds too challenging, then you can also hire a server migration service to help you out.
Your Migration Tips
If you have some migration planning tips, be sure to share them. Server migrations are a unpleasant but necessary part of running an IT business. Fortunately, with good planning you can ease the pain.