In prior versions, you would follow the path that the ES is installed on top of and it would be fine. I don't see that specified on 10 and haven't had one come up yet but I would assume the same is true.
Also just pointing out that 10 needs to run on vmware and can't be upgraded directly on bare metal MCS servers. You need to upgrade to 9, then drs backup/restore to vmware or use PCD to migrate directly from that version to 10/vmware.
These are the paths to get to each CCX logs through CLI. They may be helpful if you are having issues accessing RTMT or downloading logs through it.
If you want to download them you have to prefix "file get " and you can add one of the options (re...