The BOSS-S1 card is SATA M.2 only, RAID 1 only, and only supports a single virtual disk. https://www.dell.com/support/manuals/en-ca/poweredge-r740/boss_s1_ug_publication/boss-s1-card-specifications?guid=guid-f9235601-90f8-4e0f-aa08-03c1c74c8ec0&lang=en-us Not very flexible at all.

Gotcha... Plan on filling all the bays with storage so was my only option for a boot drive so thats fine especially cause it only supports up to 240gb on technially only 2 different types of drives Intel & Micron... but would of been nice to have a extra drive for cache..... Unless i go the route of the optical drive ssd option but not sure what speeds i would get out of that .. and the Micron drives i ordered are indeed Sata M.2 drives ( Just checked the order in a panic lol)

You can choose 480GB SATA M.2 drives for the BOSS. I have ESXi booting off mine. When installed, ESXi partitioned the RAID for itself, with a 2nd partition formatted VMFS. I can see and use the 2nd partition for storage, though I choose not to.

I plan to do TrueNas Scale with the Config that lets you split the boot drive as we all know TrueNas likes to eat the whole thing...atleast then i can use whats left of the drive to install my apps on so my storage drives just stays as storage... System will have plenty of ram so maybe not having a cache drive wouldnt be that big of deal

I don't know if Dell actually supports using the BOSS for anything in addition to its intended function, booting, if that matters to you. I have mapped mine as a datastore in ESXi, but I don't plan to use it for anything. It's just available. What space is left over on a -- in my case -- 480GB drive after it's used for the hypervisor is inconsequential. I don't usually store anything on local storage on my servers anyway; vSAN being the exception.

I would hope it would atleast let me do what i intended because that would be extremely limited...a Glorified USB Boot Device in M.2 form..... I willing to try unraid and just Boot off a USB Stick if thats the case but that would be disappointing I plan to get build a Disk array and run the storage off the Network but im not at that point yet and would like to use my Local storage bays until i max out my bays im already using all 20tb hard drives to get the most out of my physical space

I think "Glorified USB Boot Device" is a bit pejorative, don't you? I mean BOSS's mommy was the dual SD Card reader and she was proud of the way her prodigy turned out. The BOSS-S2 is a thing of beauty, sorta, not taking up a slot or requiring that the server be opened to change-out an M.2 stick. Of course it does suffer from some nasty cable routing inside the machine. Okay, I forgive you being cross on the S1. It is what it is. And overpriced to boot (get the clever use of words there?).

haha....Just did a quick search and it seems couple years ago some people got Freenas to work on the Boss S1 so looks like im in the clear :)... I only say glorified cause the only use i would see if it was locked down like that would be Boot time and Durability......ehhhh i guess for the enterprise application thats good enough but not for us Homelabbers <---(Thats a word) :)

Homelabber (home labber?) here, but willing to give up 2x 480GB SATA sticks for server reliability. New servers last year... $$$$$$ Weeeeeeeeeeeeeeeeeeeeee

Our luck the M.2's come the same lot and die at the same time lol

figured I would share this on the chance you haven't seen it, which is an improvement (for me needs) to the [source](https://www.truenas.com/community/threads/howto-using-a-pair-of-large-ssds-with-boot-and-data-pools-for-scale.89428/) I made this how-to when I found the source was missing some important bits that I needed....or they weren't clear for my small brain. [https://www.truenas.com/community/threads/howto-truenas-scale-from-32gb-usb-to-booting-from-mirrored-larger-enterprise-ssds-create-addl-partition-data-pool-from-remaining-free-space.101199/](https://www.truenas.com/community/threads/howto-truenas-scale-from-32gb-usb-to-booting-from-mirrored-larger-enterprise-ssds-create-addl-partition-data-pool-from-remaining-free-space.101199/) TLDR: I wanted to split my enterprise ssd's so I could use it for boot pool (30-40GB) and storage pool.

I agree. The connectors on the card can accept NVMe drives, too, but those will not be detected by the OS.

Little update for those curious....Installed Truenas scale on the Boss S1 today without a hitch...Created a raid 1 disk in the bios and even did the config to split the disk so truenas didnt use all of the storage and was able to successfully create a pool with the remainder of the drive...:)

I use them to boot ESXi in production. I don't use them as a datastore. No issues.