Image Processing Reference
very few moving parts, which improves the reliability. The same memory sticks are used
to deliver video to Sony CLIÉ PDA devices and currently store up to 8 hours of video
using the MPEG-4 Part 2 codec.
External FireWire Drive
This is rapidly becoming very popular as a way to move large video projects around the
workplace. A big selling point is that FireWire devices are hot-swappable. Not all oper-
ating system drivers allow this, however. Mac OS supports hot swapping by default
and you should check the device manufacturer's guidelines for any caveats on other
The video could be ingested on a machine that has high-quality digitizing hardware
attached and then taken off to a more modest desktop editing system for further work.
A range of disk sizes is available. The largest is the LaCie terabyte-sized disk. This is actu-
ally a quad array of 250-MB drives presented as a single device via a FireWire connector.
Pocket drives come in sizes from 10 GB to 80 GB, and bigger sizes are on the way. The
pocket drives are excellent for storing client projects and keeping the entire thing not only
intact but filed away offline in the fire safe until you need to work on it again. This is
cheaper than backing up to DVD or CD-ROM disks, and much more convenient. Clone the
drives if you want a safety copy.
Dual FireWire Connectivity
Apple has continuously upgraded the FireWire capabilities, and you can now connect its
enterprise-level systems together using dual FireWire 800 interfaces. This allows transfer
rates of 1.6 Gbps. This technique is sometimes referred to as Gigawire, which is a trade-
marked name. You might go down this route if you are configuring a cluster of XServe
boxes to share a FireWire RAID unit.
RAID Storage and Firewire
FireWire is a convenient interface for all sorts of video-related activities. It is quite good
for attaching a RAID storage system to a domestic or semi-professional system. A RAID
set is managed from within the standard Mac OS disk utility. Just attach 6 drives and
assemble them into a RAID set. Whenever the Mac boots, the RAID set will mount as a sin-
gle volume on the desktop. This is very robust and will mount automatically if you power
up the FireWire drives after booting the computer. Figure 29-13 shows a screen shot of the
disk utility in the process of setting up a 6-disk RAID set.
In this case the striped option was selected. A mirrored alternative could have been
chosen, which would have halved the capacity and improved the redundancy factor.
There are two caveats with FireWire drives that are important to keep in mind:
Dismount the disks before disconnecting or powering them off to avoid getting
errors from the operating system about drives having failed.