I'm trying to debug a strange problem that is causing a Mac to unpredictably switch off instantly without warning. Looking at logs, the entries most recent before this last happened were to do with
ubiquity, which I gather is to do with iCloud syncing (specifically,
mmcs_engine_create, which I can't find any relevant info about), and
TALagent, which I think might have been monitoring the live-ness of ubiquity.
The user doesn't use iCloud, so I'd like to completely disable it and related services to see if that stops the issue recurring. I've found guides on how to disable iCloud in Lion but the steps don't apply to Mavericks or above, and I'm struggling to find steps (it seems like Apple don't want to encourage users to disable iCloud, presumably because they hope to encourage its adoption).
Looking at answers to How to completely uninstall iCloud?, it suggests simply signing out of iCloud to "disable" it, but the user in question has never signed in to iCloud, so there's nothing to sign out of (yet the logs show Ubiquity still periodically runs).
(Mavericks answers would be ideal, but upgrading the OS might be an option, though I'd have to work around other compatibility issues, so Yosemite answers would be better than nothing)