I’d like to upgrade my home server from sata to u.2 storage, using a simple PCIe-bifurcation to 4x mini-sas-hd card and the Icydock MB699VP-B.
The problem is that I need hot-swap for the drives, but the server is built around a consumer motherboard which doesn’t officially support PCIe hot-plug.
However, I’m under the impression that linux can actually allow such a thing, by manually powering down the pcie slot and then rescanning the bus and by using the pciehp module with the “pciehp_force” parameter. No firmware support necessary.
I don’t think you can get hot plug on pcie from the motherboard. In order to get hot plug I think that you need a sas card that also does nvme like the LSI 94xx or 95xx series.
There are eBay combos with an 8 bay nvme u.2 cage and a SAS card with 16 channels. I don’t think that they have a pcie switch chip, but instead just give 2 pcie channels to each drive.
You can ignore the cage and just get a cable from the card to the drive if you want to give your drives 4 channels.
I wish there were more choices since the rears of ICY DOCK enclosures are almost always poorly designed afterthoughts. If you need to unplug an OCuLink cable and you’ve got the fans screwed in, good luck getting that cable out; the ports are oriented such that the fans prevent you from depressing the button needed to release the cable or even getting a good grip on the cable if you happen to manage that.
Yet, I would still stick with ICY DOCK. The only other one I’ve found would not answer my questions about whether they were PCIe 4.0 capable. The marketing materials only hinted at PCIe 4.0 “readiness” (whatever that means). A lot of back and forth e-mails and the dude kept giving vague answers to my specific questions. I’m not even going to name them.