I'd like to add a couple SATA drives (1TB+ each) as RAID 10 to my PE 2950.
Dell's website lists some 1TB drives that are quite expensive. Are there any advantages of using those over a HDD purchased on newegg or similar retailer? Or does Dell pretty much take a Seagate drive, rebrand it as a Dell, and mark it up?
The hard drives that you purchase from Dell are no different from those purchased from Newegg/CDW/etc. The only difference is that if you purchase from Dell, your likelihood of being able to make a warranty claim on the drive is much higher than if purchased elsewhere.
Physically they are the same. They have a custom firmware that ensure 100% compatibility with both the RAID controllers and other disks from the same manufacturer. Consumer grade disk firmwares often change many times in the same model line and mixing different firmwares in the same array might lead to problems (though today the controllers are more tolerant than they used to be).
Also note that the PERC6 is as SAS controller; while it can tunnel SATA commands the signaling at physical level is a bit different: SATA uses a lower voltage. You should use an interposer for plugging in SATA disks on the SAS backplane (AFAIK direct use of SATA drives on the PERC6 is unsupported according to DELL); that said, the disks will probably work just fine - but in case of troubles you're on your own.
I used some unsupported SATA drives in a RAID enclosure and while they work, we have issues booting the server sometimes. When the server boots, the RAID initializes and sometimes not all of the drives turn on. It usually requires a cold boot and then a warm reboot (or two) to get it going. Which drive(s) don't turn on is pretty random. Has been as many as 3 that don't turn on initially.
With the supported drives (that were smaller) everything worked fine. We contacted the server/raid manufacturer and the issue may be addressed in a future firmware update to the RAID, but we aren't sure.
For the application we used these drives for this was acceptable, but there are definitely applications and data that we would not be comfortable with a similar situation.
So really it depends on how important the service and data is that are relying on those drives. What kind of compatibility and support requirements do you have?
I modified my 2950 as follows. I pulled the SAS controller, Backplane, all cables associated with. Then added 4 port SATA controller in PCIe riser. Ran sata cables to front and attached to drives. ( have to move drives to sata position to get room for cables from fans) Tapped power from old backplane board connector (20 pin molex connector) which has +3,+5 and +12. Made my own Sata power harnes out of sata connectors. The system screams. Using NOVABENCH it scored 1106 without the Graphics check. NOTE: my system has 32gb ram and 2 3ghz CPUs.
With the 2950 getting to be old hardware, there are quite a few becoming available at very low prices. I have one running on Linux Mint 17.3, with a SATA RAID array, and it's working. There are the usual problems, such as fan noise from so many small fans moving a lot of air
1: You don't need an interposer card. The caddy has two sets of screw holes, one marked for SAS. The SATA set is displaced to give room for the interposer card. Use the SAS position.
2: The interposer card does allow higher-speed operation. It seems pretty obvious that any RAID array should have consistent speed, so using interposer cards would be all or nothing.
3: The drives I am using are rather old (I am trying not to spend money) but are the same model, with the same firmware. And I have spares.
4: There are two SATA connectors on the motherboard, and it would be possible to connect an eSATA backplate, though clearances for the connector look tight if you need to have an expansion card fitted.
5: There are some old SAS drives about, relatively low capacity but sometimes a cost-effective way of getting a drive caddy. Do you want to rely on one? A set of new SATA drives in a RAID array does look a better bet. The safest option may be mirroring, rather than doing anything more complicated with the data. Just how long will the hardware controller last?
