In our demonstration, we’ll be migrating from a CentOS7 virtual host to a CMK Enterprise Appliance. As with so much of Check_MK, it’s remarkably easy!
Prerequisite
Before you can migrate a Check_MK site, their versions must be compatible. The migration interface is rather robust, however, and will identify this condition if it exists.
If your site versions are incompatible, ensure you complete the needed upgrades to both sides before continuing.
Preparing The Virtual Host
Only one step is actually required on this side of the equation, and that’s stopping the site. To do this, issue the following at the command:
OMD STOP [site name]
Setting Up The Migration
With the original site stopped, next log into the appliance’s WebConf dashboard. Click on Site Management to prepare Check_MK to receive the remote site.
Click on Migrate Site:
At the migration configuration page, choose whether to preserve the original (remote) Site ID, or whether to rename it into a New Site ID during migration:
Then, enter the IP Address, the Site ID, SSH Credentials needed to administratively access the remote site:
Begin Migration
With all the information entered correctly, press Start to begin the migration process. Check_MK will log into the remote host, crosscheck compatibility and dependencies, and will then begin transferring.
This progression happens quickly, and without user interaction, and isn’t always easy to spot.
Once migration is successfully under way, Check_MK will put up a continuous status until complete
Migration Completed
When done, the same page will adjust to display a lengthy detail of conversions and checks performed. Two key locations, at the top and bottom of the page, quickly show the migration was successful.
The whole process involves minimal administrator interaction, and zero guesswork. If your credentials work, the versions are compatible, and the remote site is stopped before you begin, your migrations should run just as smoothly.
Post-Migration
Press the Complete button at the top of the page, and you’ll be returned to the WebConf Sites page. You’ll need to Start your migrated site before it’ll do any work.
If you stopped checks or notifications before migration, be sure to turn them back on!