Image Processing Reference
way to empty your bank account because it is very expensive. The high-performance
drives can only be connected to computers fitted with a fiber-channel interface. The ubiq-
uity of a FireWire connection is just so much more attractive (and cheaper). Fiber-channel
connection might be used to attach large amounts of storage to a centralized server that
shares the content out across a network.
Network-attached storage (NAS) is disk space that you mount via the network. Network
File System (NFS), Samba, and file transfer protocol (FTP) are all ways to access files
on NAS. Bear in mind that what looks like NAS to you is DAS on another machine that is
serving you. All the arguments about resilience of DAS storage apply back at that home
base. Figure 29-2 shows the basic NAS concept. NAS is a fashionable name for file sharing
that has been around for some time. It has networking bottlenecks, but it is good for 3 to
10 people to share things, provided you put in a fast network, like gigabit Ethernet.
NAS systems commonly use NFS or the Common Internet File Systems (CIFS) to
share the drives. Mac OS systems can also use the AppleTalk protocols, and when inte-
grating systems together with a mixture of operating systems you might use the Samba
Choose whether to install dedicated NAS servers or just serve the space with a spare
CPU. This is a good use for an old machine that is being retired after having been replaced
by a faster machine for your compression work.
NAS is a good solution for a system composed of several nodes. If you have a half-
dozen systems configured optimally for different tasks, then a central shared store is a
good idea. You could do daily backups and also keep archives and project reference infor-
mation there. Don't write compressor output directly to NAS. Write it to DAS and then
copy it across when the job is finished.
Massive storage capacity
Figure 29-2 File server-based network topology.