I have a Dell 2850 which I've been fairly happy with. It runs RAID 5 to 6 Hot-swap SCSI drives, but I'd like to add some cheap storage. So I bought an Intel PCI-X SATA raid card and tried to install it.
Problem is that my 2U server doesn't have any SATA power connectors(Doh!!). I have two options I'd like to try.
1) Can I cut out 2 or all of the SCSI drives and swap them for hotswap SATA?
2) Can I add SATA power connectors to my board/power supply or a external SATA power?
Adapters are available to convert from a molex power connector to the SATA connector, with the caveat that the molex connectors don't have the 3.3 volt feed that's technically part of the SATA power spec.
I haven't personally run across any drives that actually need the 3.3V connection, but you'll want to check with your specific drives.
This is absolutely do-able and not too hard, just a little patience. I've done it myself on a few 2850's that we have.
I modified slots 0-3 to accept SATA drives. I have 1TB drives in them with ZFS, raidz2.
Slots 4-5 were kept as is so I could RAID1 them with Nexenta.
The cost is under $40, not including stock trays or SATA card. You will have to do a little soldering to get the power to the drives, a little trimming on the alignment post of the SCSI connectors, and a little epoxy for the SATA+Power connector. Power is taken from each SCSI connector. With this mod, you can even hot swap the SATA drives without any problems whatsoever.
Note, you don't need the 3.3V feeds.
EDIT:
I'll see if I can put together a how-to. Meanwhile, here's the parts list.
Left-angle sata adapter, 1/2 meter, from estore.circuitassembly.com, P/N SKU:U709090. One each for each SATA drive. The depth of this connector is very important. Do not buy them from other vendors unless they look exactly like the one shown on the website. If you convert slots 4 and 5, then you will need a SATA extension cable for them.
Epoxy. Use any available that will harden and is resistance to some heat. Do not use conductive epoxy. I use a two part epoxy, but can't recall the exact type off-hand.
Drive trays. Use any available except P/N 0D988. This specific tray does not have the required alternate drive mounting holes. This is important to make the tray fit perfectly in the slot.
SATA interface card. I use AOC-SAT2-MV8. Works great.
When and if I have time, I'll figure out how to get the power and activity LEDs to light up too!
To power your drives just cut off a cpu power connector from a old power supply and cut off a molex connector and wire them like this Power Diagram:
Then in the front drive tray part of your 2850 you will see a little rail and under it the is where the SCSI cables connect to, directly right from that there should be a little cpu power connector
Just plug in your modified power cable in and it should power up!
Also just a note, i have checked the voltages and this is indeed correct, i tried it with 2 different 2850 models and it works. also checked the voltages on each pin. Also make sure that the connector lock is on the left when your looking at the unit from the front. I currently don't know how to make it hotswapable so i'll leave that up to you to figure out!
