Adding external storage with LFF on a Dell R720 SFF with PCIe passthrough


Feb 5, 2024
I am using a Dell R720 for my homelab (very new to the game) and realized that It's going to be very very very expensive to get storage with 2.5" drives. I'm trying to figure out how to add 3.5" SATA drives to the Dell and not break the bank. I'm running Proxmox and have TrueNAS Scale running on Proxmox with TrueNAS getting access to the LSI on IT mode, so it has full PCIe passthrough and direct access to the drives. I was wondering what I should get to essentially move away from the 2.5" drives and add 3.5" drives that's quiet and not going suck a lot of power. I have the Dell R720 running right next to my bed actually and its torarable. So hoping to not add something thats louder. The goal is to have around 15-20TB of space(currently). So nothing crazy. And should be able get this with around 4 drives with a single drive failover. Love to get some advice.

Thank you kindly.


Jan 26, 2022
Get a used JBOD enclosure that can fit a few drives (frankly you can build one yourself if you got a spare PSU, some confidence with wiring to your main psu, some spare screws, a fan or two, and access to a 3d printer; check your library if you don't own a 3d printer, many have this service). SAS wire quality/length from the HBA to the JBOD as well as flashing the HBA to correct firmware & IT mode are the only pitfalls I can see.

Depending on what you got locally/can scavenge on ebay you can very likely do this for under $100. If you have access for the DIY method you looking at under $50.

Also you mentioned an unspecified LSI; make sure it is flashed to lastest firmware & IT mode. More knowledgeable people than me may provide insight to vendor specific (Dell) HBAs & possible issues/fixes.

Also hard drives like to make noise, so hopefully that doesn't drive you crazy when they scrub or run smart tests. Would recommend not keeping in bedroom if possible unless you love the datacenter flavor of whitenoise.

*Edit// Per the dell whitenotes the R720 should support 3.5" bays? Maybe it'd make more sense to look into swapping the the 2.5" bays for 3.5" than what I listed above.
Drive bays Up to eight 3.5” drives or up to sixteen 2.5” drives
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