My linode had a 297 day uptime until the migration. After the migration, Apache2 would start, then stop.

Does anyone have the same problem? Any suggestions?

service apache2 status --> Apache NOT running

/etc/init.d/apache2 start --> [OK]

service apache2 status --> Apache NOT running

This is really confusing. I have not made any changes since the migration.

I've created a "test.html" on the www root directory and it's inaccessible from the DNS name and IP address.

Any help would be appreciated.

Take a look at error_log and see if it gives you any details on the problem. It's also possible that Apache is being started but the "status" command fails for some reason. You can check if it's running and listening on port 80 with netstat -lvpnut | grep :80.