How do I power SATA drives in my DELL poweredge 2850?

Question

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?

Solution 1

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!

Solution 2

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.

Solution 3

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.

1. 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.

2. 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.

3. 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.

4. 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!

Comments

[Admin]

Wouldn't it be easier to just buy an external sata enclosure? A 1 drive enclosure is ~$40, a 5 drive enclosure i ~$150. The multi-drive enclosures will require a SATA controller that supports port a port multiplier. A 4 drive rack mount enclosure is about $450

[Eric Fossum]

I don't have any power connectors... The SCSI drives get their power through their hotswap bays

[ravi yarlagadda]

What kind of SCSI? If it's SAS (Serial-attached SCSI), then the power and signal connectors are compatible with SATA drives. If it's Ultra-320 or somesuch, then to put SATA drives in your hot-swap bays you would need a different backplane with the correct connectors - for both power and signal.

[Eric Fossum]

Well back to my question; I know I cannot just swap back-planes, can I cut part or all of it out and solder power off the existing connections and run SATA cables for the data?

[ravi yarlagadda]

Depends how much of a do-it-yourself modding project you want. Yeah, that's absolutely doable, but getting the spacing right on the connectors would be tricky.

[Eric Fossum]

I guess that's what I'll have to try, starting with like two of coarse. I wouldn't want to destroy the whole array :) Just to be sure, does the SCSI connector have all the power connectors required?

[ravi yarlagadda]

You'd still be running with no 3.3V feed, but 5V and 12V are definitely used by, and available on, your existing backplane. To isolate and connect to them to make them available to the new drives might be interesting.

[Eric Fossum]

So, I just took the backplane out of my server and I've got a couple of ideas. The board seems to get all it's power from a three wire source at the bottom near a 6x~15pin HDM connector, but there is a source at the top that says tape power. Any ideas as to which is more suitable?

[ravi yarlagadda]

@Eric I'd say break out a voltage meter and check - hopefully each has both a 5v and 12v feed. If so, then either should be ok (as long as one of them isn't on a weaker power rail).

[Eric Fossum]

Already did that, I got 12,5,0 on the HDM_PWR and 0,12,5,0 on the tape_pwr (3 vs. 4 pin). Do you think the tape_pwr comes from the board power?

[Eric Fossum]

crazyperson - If you can add a parts list I'll select this as the correct answer! It sounds just like what I wanted to do in the first place. (Sorry for the huge delay, I've been busy with school and figuring out why my raid has 5MB throughput)