Timothy
Parker Consulting Incorporated
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Turnkey Web Servers Part 3: Cobalt NASRaQ In the last column we looked at Cobalt Network’s RaQ system for providing Web hosting and other Internet services. The RaQ is designed primarily for ISPs and organizations that need to provide virtual hosting services, and as you read last time, I am mightily impressed by the capabilities of this inexpensive appliance. To finish off the RaQ subject, there’s a spin-off product from Cobalt worthy of mention, too. It’s called the NASRaQ and it’s designed to be a network attached storage (that’s NAS for those not keeping up with the acronym soup) device. NAS units are essentially stripped down computers that are attached directly to a network, such as a LAN. They are dedicated to providing hard disk storage, and usually have from several dozen to several hundred gigabytes of disks all managed by a small computer in the NAS unit itself. The advantage to a NAS is that it is usually not much more expensive than a small computer (you don’t need the fastest Pentium CPU to manage a bunch of disks) and you have a dedicated disk drive location ideal for network-wide delivery. Everyone on the network accesses the NAS as though it was a local disk drive using drive redirection (mapping the network drive to a local drive letter in Windows, for example). When the NAS has been properly set up, corporate-wide access to data is enhanced. The problem with NASs, though, is that they are network attached and hence limited to the network bandwidth. To give you an example of a NAS, I recently need to add about 200GB to my internal network. The drives had to be accessed by three different workstations, all multiple-processor units involved in crunching video information all the time. Putting all that data on one device would have imposed a slow-down while the device handled requests from the other workstations. Splitting the data storage into three separate boxes wouldn’t work well because we would run into boundary effects when one workstation’s drives got near capacity and the others were not. Adding a separate box with the hard drives all controlled by a RAID SCSI controller, all accessed through the network, seemed logical. There are many vendors of NAS units on the market, with many different solutions. Most are SCSI setups in RAID arrays, although there are a few IDE NAS towers available (and the IDE versions tend to be a lot cheaper than SCSI arrays). Most, though, are SCSI, primarily because SCSI drives are faster, more versatile, and much more flexible when it comes to daisy-chaining devices. I installed a NAS on my network (controlled by a Linux kernel) and tried it out for a few days. It was easy to map the 200GB to each of the three workstations, and they all worked over the network fine until it came time to have all three workstations stream video at the same time. Then the network bogged down. A typical Ethernet 10Mbps network runs anywhere from 1 to 4 Mbps typically, seldom peaking above that. With streaming video from multiple sources, the network wasn’t fast enough. When I bumped the Ethernet system to 100Mbps (which really runs around a peak of 40Mbps in most installations) the problem was solved. The NAS unit was fast enough, cheaper than buying a dedicated Windows NT drive setup, and provides a single point for backups. Back to the NASRaQ. Physically it looks like the RaQ, a thin, rack mount box with front display panels and a few buttons. There’s not a huge amount of capacity in the NASRaQ, which is its only real shortcoming. You can have up to 32GB of disk space in the unit. The 32GB is usually composed of two different drives, and can be stripped (RAID 0) for better performance. Where the NASRaQ comes on strong is the ability to stack these units. Need more storage? Add another NASRaQ. The unit is simple to install, requiring about ten minutes, and the Linux operating system is preconfigured to allow the NASRaQ to basically plug-and-play with Windows, UNIX, Macintosh and NetWare networks. A setup wizard makes installing and configuring access a quick job, and then the NASRaQ gets out of the way, allowing users to access its disk storage over the network. The possibilities for the NASRaQ are interesting. Although I’ve treated these NAS units as network-wide storage devices, you could easily install NASRaQs for specific purposes, such as for a single point of access for a particular project or workgroup. The NASRaQ software lets you control access any way you want quite easily. The cost of the NASRaQ is a little higher than just buying hard drives, but not by much. The Linux operating system and included software make it a snap to install and configure, so there’s no experience with NASs or Linux needed. It’s an impressive, easy way to expand network disk storage. Now, if only they would make 200GB units! Next column, we get back to the Cobalt Qube, one of the more interesting approaches to adding a standalone Internet server. |
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