Unlike the Kurobox's cousin, the LinkStation, the Kurobox does not come packed with a hard drive. The Kurobox uses an IDE Host Controller and currently only supports IDE devices, not Serial ATA (SATA) devices. Any 3.5" IDE/PATA hard drive is ideal for use in the Kurobox. It may be better, however, to use a slower 5400rpm hard drive instead of a faster 7200rpm or 10000rpm hard drive, especially if your Kurobox will be in a warm-hot climate. The cooling fan may not provide adequate cooling for the hard drive, and the higher temperature of a faster hard drive may cause catastrophic hard drive failure. When installing your hard drive, it should be set to Master or Cable Select by the jumpers.
Hard Drive Management
There are LEDs on the front of the case which can be used for hard drive diagnostics. These include showing when the disk is full, or when the disk has failed.
IDE Ribbon Cable
The Kurobox's ribbon cable is soldered onto the main board and is just long enough to attach to the hard drive when mounted. You can remove this ribbon cable, and replace it with a longer cable with a slave connector, or a socket which will allow you to easily replace different cables.
Second Hard Drive
A second hard drive or other IDE storage device can be connected to the Kurobox, but you will need to replace the standard IDE ribbon cable with one that has a slave connector on it. The Kurobox power supply may not be able to handle the increased power drain of a second storage device, so you may need to route power from somewhere else. A second 3.5" IDE hard drive will not fit inside the Kurobox case, so you will also need to find a location to store the extra device. Some people have put their second hard drive in an external case while other's have modified the housing and turned their Kurobox into a "Kurocube".
Software RAID is possible on the Kurobox
Hard Drive Alternatives
Instead of a standard 3.5" IDE hard drive, you can use a different storage medium. These require you to purchase special adapters to connect to the Kurobox's IDE ribbon cable. The ribbon cable is very short and the hard drive mounting options are limited, so please take note of the size, shape, and connector positions when making your adapter selection. Note that flash memory based storage solutions have a limited number of erase-write cycles and write access may be slow due to the way that they operate.
2.5" IDE Hard Drive
These hard drives are usually found in laptops because of their small form factor and light weight. This should lower the overall temperature and noise vibrations of your Kurobox. You will need a 40-pin to 44-pin adapter to make this work. It may be possible to have two 2.5" IDE Hard Drives side by side inside the Kurobox without any case modifications, however this has not been confirmed.
Using an IDE to Compact Flash adapter, you can use this solid state device to store your data. There are no special drivers required, and the CompactFlash will be seen by the Kurobox as a regular hard drive. This device, however, will not be hot swappable like a memory card in a USB memory card reader, due to the limitations of IDE. A Microdrive, or 1" hard drive will work the same way, but unlike Compact Flash is more fragile and sensitive to temperature changes like a normal hard drive.
IDE Flash Module
These offer the most compact solution for your Kurobox, but are limited in storage size and are rather expensive. With this alternative, however, you do not have to deal with any special connection adapters.