Server cloning question
Cloning a Linode involves copying the Linode's disk, so during the clone there will be more disk I/O than normal. However in most cases this won't be enough to affect the normal operation of a Linode.
That being said, we recommend shutting down your Linode before cloning it if there's any chance of a database transaction taking place or new files being created during the cloning process, as otherwise the new Linode won't be an exact copy.
If you do need to clone a Linode while it's running, I'd recommend making a separate copy of any database with a tool such as mysqldump to ensure the database is accurate.