Most of Debian's infra is elsewhere, but OSU does host a backup server, logs server, a bugs.d.o frontend, POWER/MIPS/HPPA/RISC-V build/porting servers.

https://db.debian.org/machines.cgi

Similarly, I assume RedHat hosts most of Fedora's infra and OSU does POWER/IBM Z stuff for them.

I would've assumed that Red Hat/Fedora are well-catered for now in terms of POWER and Z, considering who now owns Red Hat.

You'd be surprised, this is one of the ways in which Red Hat stays independent from their mothership. IBM prefers to donate to OSUOSL and Red Hat uses it for Fedora.

Then there are private labs, internal to Red Hats, that are used by developers especially for testing, but they're not stocked particularly better than they were prior to the acquisition.

They need university budget for items that aren’t donated in-kind rather than as cash by sponsors. Build servers can be donated by granting OSU access and paying the bill. But someone has to manage those donated services, and none of the existing donation agreements apparently include cash on table to pay for that headcount (since they did not until this year).

Bandwidth is donated by TDS Telecom. I suspect that physical hosting is provided by the University and servers seem to be provided by IBM.

My understanding is that a lot of ISPs use linux mirrors as an offset for asymmetric bandwidth, which can lead to one-sided network charges. As such, they're happy to donate bandwidth to the degree it benefits their negotiations elsewhere.