Are all SAS drives hot-swappable?
Can get a 300GB Cheetah 15K SAS 3.5 disk for quite a bit cheaper through another supplier vs. Dell's out-of-warranty depot (for an aging PowerEdge server). Specs are identical, wondering if there's any difference that I'm not seeing as far as hot-swappability (<-- just made that up).
Assuming it's more of the controller/connector vs. the drive?
Solution 1:
Yes, they're hot-swappable...
The drives are usually compatible and the hot-swap ability is built into the SAS specification. The SFF-8482 connector on the drives is a standard and there's nothing physically unique to Dell drives versus the OEM.
I'd still prefer to use the manufacturer drive part number before going OEM, though. If you dig a bit harder (eBay, refurbished, liquidators), you'll be able to find the Dell-specific drive you need at or below the cost of the OEM.
Solution 2:
In theory, the standard says that SAS handles hot swap gracefully. In practice... well, you're taking a bit of a chance. Dell will kick up a royal stink if there's even the slightest chance you might have used a non-Dell drive in the machine (we're having terrible troubles with them at the moment -- they suggested that because the machine had previously had a non-Dell drive in the machine, all warranties were void!). If you're out of warranty anyway, it's not really much of an issue (Dell will tell you to get bent either way), but you are taking the interoperability risk by using a non-Dell drive.
Solution 3:
Dell (among others) asks a lot more for some components than other sources do. Some of this is because they actually do extra testing and will guarantee that their components work fine in their machines. A large part seems to be extra profit for Dell though.
This is why I always buy Dell servers with minimal memory and the smallest drive you can get. When the server arrives test it, set aside the official Dell drives and replace them with your own. This way you get the best price/performance.
Do your research though. E.g. just swapping Dell branded 160GB SATA drives with 2TB SATA drives might work, until one fails and you discover it has the wrong TLER or that its firmware is not fully compatible with a HW RAID card. I spent days peering at specifications and I never had any problems with my cheap solution. Having said that. I spent a lot of time checking specifications and compatibility. If time is money for you, and it is just one server then buying directly from Dell might be best.