Everything you need to know about Hot-swappable hard drives

First of all let me point out that I haven't the foggiest notion about that Banana Pi device. I suppose it's some sort of system board that's used for special purposes that interest you. I can proceed on the basis that you're interested in effectively transferring (from time-to-time) the data from a HDD/SSD from your desktop PC to the Banana Pi, temporarily installing the drive in that device, and then (as needed) returning the disk to your PC. And all during this time the data on the disk will remain inviolate.

Also that you don't want to shut down your PC when you remove the drive from the PC. In order to accomplish this are you willing to work with at least two drives - one your boot drive, the other the drive you will be removing from the PC for temporary transfer to the Banana Pi device? Or were you just thinking of a single drive that contained both your OS and the data you want to transfer? If you're thinking along the latter lines I don't know of any practical system you could use in terms of a hot-swappable removable hard drives system.

In any event provide a bit more info re the above and we can go on from there if you choose.

Easy to do. Buy hot swap bay (I have the 4-drive Rosewill at the office for a RAID10 data setup). Make sure BIOS has hotswap enabled for that drive. Might need to disable write caching in Windows for that drive. Have at it.

as long as you get one that's USB 3.0 (and not USB 2.x), it would be fast enough, and faster than any current HDD could manage anyways.

I've been working with removable hard drives (mobile racks) for about 15 years now and I highly recommend this hardware configuration for a desktop PC. The installation of such is quite simple - not any more complicated than installing a CD/DVD optical drive in one's system.

The beauty of this type of hardware configuration is that you can work with multiple HDDs and/or SSDs, each disk effectively isolated from one another (when desired) containing different operating systems, different storage types, different disks. Through a simple turn of a keylock or power switch on the mobile rack, you can thus boot to this drive or that drive without the need for any "bootloader" or any other multi-booting software, as well as no need (in most cases) to access the motherboard's BIOS to change the boot priority order in order to boot to this or that particular HDD.

In your situation you'll have a simple & effective way to remove (and later reinsert) the HDD from & into your system, all the while on a hot-swappable basis. Also, you'll have SATA connectivity. The docking station recommended by giantbucket is another option, however it's a USB device and I think you would be better served by equipping your PC with the Orico (or similar) device having SATA connectivity and the added advantage that it's integrated in your system rather than needing an external device such as a USB docking station or other USB external enclosure.

The only downside I can see with the Orico device is that it's strictly designed to house 3 1/2" HDDs. So you won't be able to use a SSD with that device should you later decide to go that route. But you've indicated you'll be working with a HDD so I guess that isn't a deal-breaker. The mobile rack we've pretty much exclusively worked with over the years is this one...
http://www.newegg.com/Product/Product.aspx?Item=N82E16817993031
It too is designed for 3 1/2" HDDs however it's easily modified to accommodate SSDs. Unfortunately Newegg no longer carries this model and I haven't been able to locate any on the net at reasonable prices. (We used to pay about $12 per unit for them.)

Anyway, pursue Newegg's mobile rack offerings. You may find one or more that appeals to you more than the Orico model. Many of those racks are designed for installation in a 3 1/2" bay and are designed to house 2 1/2" (SSD) drives. One aspect of the Orico particularly appeals to me - it has an ON-OFF power switch. Many of these devices do not have such - they either have a keylock mechanism or simply a lever arrangement to remove the disk. It's not a crucial factor but I prefer a power switch in addition to the release disk mechanism.

This is the model I use ,will take a 3.5+2.5 drive ,fits in a 5.25 inch bay.
Non obtrusive ,has spring loaded flaps for if a drive isn't inserted to combat dust entry & power & eject buttons.
http://www.amazon.com/gp/aw/d/B007Q4EZEA/ref=mp_s_a_1_4?qid=1424445586&sr=8-4&pi=AC_SX110_SY165_QL70&keywords=icy+dock&dpPl=1&dpID=41A%2BLVHj8fL&ref=plSrch

Thanks for the info on this model. We have worked with Icy Dock mobile racks in the past but for one reason or another weren't thrilled with them. But haven't had any experience with this DuoSwap model.
The specs seem to infer that the device will accommodate 2 1/2" disks from 9.5 mm - 12.5 mm. As I'm sure you know virtually every recent SSD is 7mm thick. And I noticed some negative comments on Newegg about the eject mechanism with respect to the SSDs although it wasn't clear whether the issue involved 7 mm SSDs in particular. Could you comment on this?

I take it your completely satisfied with this device?

Absolutely satisfied - its fitted to my main desktop & mainly gets used for the 3.5inch drive as my htpc is a Silverstone with 2 hot swap bays fitted as default.
The eject buttons were stiff for the first few weeks but loosen up considerably after some use.
Standard 9mm upwards 2.5inch drives are fine but I have a suspicion that the eject lever mechanism may miss slightly on a 7mm ssd & the drive would require some manual help to slide out.
I don't have a loose ssd to test but looking at the lever mechanism it 'just' hits the top of a 9.5mm drive so you are probably correct.
The drive can be manually slid out though as there is no actual locking mechanism on insertion.
Its certainly very well made & has stood some abuse ,at least for home use - my only qualm is it obviously requires 2x sata cables (1 for each drive) but also requires 2 x sata power cables which could have easily been avoided.

Thanks again for the info. The possible problem with 7mm SSDs could be a serious one for me. For one reason or another we're involved in situations involving removing/re:inserting these disks in our mobile racks so problems in this area could be a deal-breaker for me.

It's interesting that you consider the need for 2 data & 2 power cables with this device a negative. Frankly we prefer that kind of arrangement because of the resultant absolute isolation of the disks from the system when needed. (My understanding is that the device as separate power switches for the 2 1/2" & 3 1/2" disks. If I'm wrong about that please let me know.

ASIDE TO MOOSEMAN...
I forgot to mention that if you do go the route of installing a mobile rack (removable HDD) ensure that your BIOS setting reflects hot swapping for the SATA connector the removable HDD will be connected to. Ordinarily (in most BIOS settings) the default is Disabled.

^ the minor annoyance would not affect most people.
My PSU has a non standard cable layout ,a 4 cable sata ,& a 3 cable sata with a floppy connector - running 8 drives meant I had to use a molex to sata adapter.
Yes the drive bays are independently switched/powered - they could easily have been run from 1 sata power cable is all.
I wouldn't recommend the dock for professional use really ,I'm not sure it would stand up in those kind of uses.
For home use its solid IMO though,although most people would rarely use the 2.5inch tray I wouldn't have thought.