Ask Dan: SATA controllers and trayless baysDate: 11 February 2008 Last modified 03-Dec-2011.
It's HTPC-building season in my neck of the woods, and my question is this:
The Antec Fusion V2 MicroATX case looks like a product of years of careful industrial design.
It looks like it belongs in any discerning audiophile's equipment cabinet. To keep things cool and manageable, I wanted to use removable drives to move data in when I want it, and keep the rest offline since I'm only likely to be watching one movie at once. Kind of like tape cartridges, but this-millennium.
So, is there an enclosure for SATA 3.5 inch disk trays that doesn't look like it's been attacked with a hacksaw?
My Google-fu appears to have failed me despite much searching. I came pretty close when I found the IcyDock MB663UR-15. It's pretty sleek, push drive in, use data, pull drive out.
The problems are that it's for 2.5" drives, and it converts to USB. 2.5" drives are horribly expensive, and I'm pretty sure that Vista chokes when watching DVDs off a hard drive over USB (Protected Video Path grumble grumble).
I don't want glaring bright LCD displays, or a flimsy lock, or some honking big grille that you could bulldoze something with. I just want it to look like it fits in around all the other AV gear.
Does my mythical swappable hard-drive-cartridge system exist?
SATA hard drives have made this easier, because the standard SATA power and data connectors are well suited to being connected and disconnected directly.
So you can have "trayless" 3.5-inch drive trays that fit in a 5.25 inch bay, into which you just plug bare drives. When you open the front door of the rack, a lever doodad pops the drive out so you can grab it.
This is a cheap and simple solution, and you can add more drives without buying anything but those extra drives. The old kind of hard drive rack, like the one I reviewed many years ago here, required you to buy a new caddy for each new drive you wanted to be able to swap.
If you want hot swap - the ability to swap drives while the computer's on - then you're going to need to connect the back of your trayless drive bay doodad to a SATA controller that can handle hot swap.
Many - probably still most - normal motherboard SATA controllers can't do this, though the controllers built into some server boards can. Nvidia nForce-chipset motherboards in current versions of Windows are apparently hot-swap-capable, as are many chipsets under Linux, but don't assume that your motherboard will be.
If you have to buy a separate controller that can do hot-swap, you should expect to pay at least a few hundred dollars. That's because hot-swap usually comes along with lots of ports and fancy RAID modes, in controllers like this four-port or this eight-port 3Ware. Cheap hot-swap-capable controller boards show up on eBay from time to time, but they're often PCI-X or 64-bit PCI boards pulled from servers, which aren't any use if you've got a normal PC.
If you're only swapping drives once in a while, though - which is likely to be the case for HTPCs or even many video editing boxes, where you keep a whole project on one drive - hot-swap's no big deal. You can just turn the computer off when you need to swap drives.
Naked hard drives are also, of course, not particularly durable. You'll need somewhere to store them safely when they're not in use, and you should also take basic anti-static precautions when handling them. Realistically, a nice solid wooden drawer with a few layers of newspaper in the bottom (into which you only put a single layer of hard drives...) will do fine for storage, and just handling the drives by the edges should prevent them from getting zapped. You'll be sorry if you drop one, though.
Still, you can't beat that price.
Aus PC Market have one model of "trayless mobile rack", which sells for $AU57.20 including delivery anywhere in the country. It's available in black or beige; Australian shoppers can click here to order the black model or here for the beige one.
I don't think it looks too bad. The black one'd fit a black HTPC case well enough. There may be a super-sleek looking trayless rack somewhere, but this particular model seems to be quite popular; you can find the exact same thing under many different names from many different companies (including IcyBox, again).
Here it is, for instance, from drive-adapter specialists Wiebetech. They call it the "RTX100-INT", and sell it for a pretty reasonable $US29.95 plus delivery. Delivery is cheap for US customers, acceptable for Canadians, and too expensive for everyone else to not just buy the same thing somewhere else.
Umpteen dealers stock what looks like the same item. I think some versions have power and activity LEDs and others don't, but that's about it for the differences.
I see repeated references to separate channels, but the instructions go on about settings for RAID 1 or RAID 0, but nothing about the settings for JBOD.
The only advantage of JBOD over RAID 0 (which is a striped set without redundancy, so it's not really a type of "RAID" at all) is that you can expand JBOD volumes by adding more drives to the end. Since the card you're looking at can only accept a maximum of two hard drives, I think you'll find that JBOD wouldn't be a big selling point for it.
JBOD support matters more for controller cards that can support four or more drives, and they're more likely to offer it. But there's very little reason to bother doing JBOD in hardware (cheap RAID cards are hybrid hardware/software solutions; most of the RAID calculation work is actually done by the driver software), since JBOD is computationally completely trivial. You might as well just do it in software through your operating system.
In Windows, this is very easy. Microsoft calls JBOD a "spanned volume", but the principle is exactly the same, and mainstream versions of Windows have been able to make spanned volumes out of "Dynamic Disks" through the Disk Management interface since Windows 2000.
You need the more expensive "Server" versions of Windows (or any remotely recent version of Linux or Mac OS, or, as a reader just pointed out to me, one or another Media Center Edition of Windows...) if you want to make RAID 5 volumes. But if all you want is JBOD, you can set it up - and expand volumes onto new drives, too - with the ordinary flavours of Windows.
If any drive in the spanned volume dies or is removed, the whole volume will of course be broken and probably unrecoverable. Cheap RAID controllers are much the same, though; you have to pay for a proper hardware-based 3Ware or similar controller before you can count on RAID recovery (or, sometimes, even repair...) actually working.
Australian shoppers can buy all sorts of storage hardware from Aus PC Market.
Click here to order!