Disk Jockey Functions

Of the 8 modes available, 3 are designed to operate in conjunction with you computer, and 5 can take place stand-alone, with the Disk Jockey being the only thing powering the drive(s). First, lets talk about the computer-based functions:

1. Standard Mode. This is the mode used to mount a hard disk. To mount a hard disk means to hook it up and set it so that it can be used by your computer. This mode, thus, allows you to hook up to two drives to the Disk Jockey, plug the unit into your PC using either USB or Firewire, and then use the drives as external storage devices. In my testing, it took a little time to figure out how to do this. The first drive I plugged in simply would not be detected by Windows. I then found in the manual that the drive has to be set to Master to work correctly. I made this change then found out that I had to push the power button a second time to actually mount the drives. Once I figured it all out, the drive was correctly detected by Windows and, sure enough, I was able to access the drive as I usually do. Very cool.


2. Mirror Mode. Basically, this mode sets up a simple RAID-1 array, but externally. You set up just like Standard Mode, but when you connect up to the computer, instead of seeing 2 drives, it sees only one. However, whenever you perform an operation to that drive, it is simultaneously mirrored to the second drive. This is good for keeping a real-time backup of your data. Unlike real RAID-1, though, Disk Jockey will not automatically rebuild the mirror should one drive fail, and is not hot-swappable. Also, you must ensure that the drives are identical before using in Mirror Mode. Either erase or copy the disks using the other modes of the Jockey.


3. Combine Mode. Basically, this mode will mount two hard drives together as one drive, thereby using the capacity of both drives as if they are one larger one. The data is not striped as in RAID-0, though. Instead, it will write everything to Disk 1, then simply start using Disk 2 when 1 is full. This mode will lock the two drives together if you intend to still use the data. If you remove one of the disks, the data on both is inaccessible.

The other functions of the Jockey can be performed stand-alone, meaning without a PC. They are:

1. Copy Mode. This mode will perform a sector-by-sector copy of Disk 1 onto Disk 2. There is no selectivity to this copy. It will copy every track, sector and byte. So, if you need to select only certain partitions to be copied, you will need another solution. This can be good and bad. On one hand, the Jockey will make perfect copies and can do so very quickly, but at the same time, because it copies everything (including empty space), it means that it cannot copy data from a larger drive to a smaller one, even if the larger drive is holding barely anything.
   
   Doing a copy is a bit interesting due to the simplistic nature of the Jockey. Once you comply with all the rules for the disks and finally get a copy going, the feedback is so little that its hard to know what is going on. The only feedback available is the single little LED light on the top. And to know the progress of the copy, you have to count the number of blinks of the light and use the manual to decipher what it means. Once the unit is done copying, it will let off a buzzer then power down automatically.


2. Compare Mode. Usually used after a disk copy, this mode will verify that the copy is an exact sector-by-sector duplication of the original. This is also useful in order to prepare a set of drives for mirror mode.


3. Disk Check. This mode will perform a full check of the drive, checking drive electronics and performing a full scan of the disk for errors. The usefulness of this mode is severely limited, again, due to the simplistic nature of the device. Progress indicators are, again, blinking LED lights. If there is a problem found on one of the disks, it simply emits either a series of long beeps or short beeps, the length of the beep only telling you which drive the error is on. So, basically, you know there is a problem, but that’s it. No telling you what the problem is or how to fix it. So, its effective at telling you whether a problem is there or not, but don’t expect anymore from it.


4. Disk Erase. There are two modes (6 and 7) on the Jockey for disk erasure, and the only difference is that one mode does one pass over the drive, and the other one does three passes. At the technical level, mode 6 will write a long string of zeros across the whole disk. This is a kind of “quick erase”, but higher-end data recovery experts may still be able to recover data from the disk. Mode 7 will perform 3 passes over the disk. It is more thorough and will make the data unrecoverable.