SirLagz

I hit up /r/sysadmin for some guides for a friend, they suit this sub as well though so maybe we should pin these for those "what should I do with my lab" posts.

Really depends on whether you're more comfortable with a WebUI or Command line.

pfSense CE is still perfectly fine, and a lot of features that are behind the paywall are more for commercial users, less for homelabs/home users.

If you are still worried, then Opnsense is a pfSense alternative that's built from the same base as pfSense as it was forked from pfSense a few years ago.

Also, you won't be able to run Proxmox on the Pi. There is Pimox, but I don't know how that would behave if it was in a cluster with Proxmox.

Look at the system requirements for whatever software you want to use?

Do everything in this post - https://www.reddit.com/r/sysadmin/comments/3z7qd9/comment/cyjynxh/ - with your homelab.

Then you can say you have some experience managing AD etc etc.

I'm using an AMD Turion and running ~6 VMs on that. I used to run pfSense on it as well, but I had to take out the second network card to put in a HBA.

Depends on what functions your pfSense box is currently serving.

yes

If you don't care/want/need new new new stuff, the old X299 chipsets with an i9-7980XE for example would give you 44 lanes with 128GB of RAM

What hypervisor?

If you can do USB passthrough, you could have a VM whos sole role is to share out that USB drive through USB passthrough, and you just shutdown the VM before you unplug the USB drive.

Personally, I would just setup my own private cloud.

I shelved my big rackmount server/NAS in my 550mm rack

So. There are NVMe to U.2 Adapters, like this - https://www.mwave.com.au/product/silverstone-mua01-m2-nvme-ssd-to-u2-ssd-adapter-ac69201

That converts a NVMe SSD to something resembling a 2.5" SAS SSD.

Then there are SAS/NVMe Hotswap bays, like this - https://www.intel.com/content/www/us/en/products/sku/99083/2u-hotswap-8x2-5inch-sasnvme-combo-drive-bay-kit-a2u8x25s3phs/specifications.html

Then there are these cables that connect Occulink (PCIe) to SFF-8643 - like this one - https://www.microsatacables.com/oculink-sff-8611-straight-male-to-sff-8643-cable

Then there are PCIe to 4x SFF expansion cards like this - https://www.amazon.com/Expansion-Adapter-SFF-8643-Indicator-Breakout/dp/B0B7BHM954 - This will require hardware support for PCIe Bifurcation, but will provide you 4x SFF-8643 sockets per each 16x slot.

Do with this information what you will.