I have bought a nice little disk to store my backups that require a lot of diskspace (smaller stuff I backup with tarsnap).
It is a Seagate 4 TB Backup Plus Portable, and I bought it here
I have not yet unsealed the package, because I noticed the text "Use between Windows and Mac". This seemed unlikely to me. Just to be sure, I called Alternate to ask if I can repartion it, put any filesystem on it and just use it on OpenBSD or GNU/Linux. They told me that only Windows and Mac is supported, and they said it was very unlikely it would work on anything else.
I still find it unlikely, but just to be sure: do you have any experience with drives like this that actually give problems on the better operating systems?