Building a file server

First decision: what manufacturer to choose. Computer hardware can be divided into "tiers" or levels of quality, with "Tier 1" being the top and "Tier 3" being the lower end of the market. With a file server, because it is so important to a network, it is wise to choose a "Tier 1" machine, such as Hewlett-Packard/Compaq or IBM. The quality of the design, the ruggedness of the components, and the reliability of the manufacturer are all vital factors in choosing such a vital piece of equipment.

Notice that the CPU is not exactly "state of the art" - many home machines now have Pentium 4 chips running at 2GHz. I think server manufacturers tend to be a little conservative when choosing CPUs for their servers - they may wait to be absolutely sure that a CPU has no problems before putting it into a mission-critical server.

Also notice the price: it is about 3 times the cost of a home PC, and does not include a hard disk! The extra cost can be explained by its high quality components and special design to allow for maximum expandability. The last things you want in a file server are cheap components or an inability to expand its abilities when necessary. Our current file server has been running constantly for three years: it has never been turned off. Try doing that with a "Green Guide" cheap PC!

The "base unit" server, with no optional extras, comes with 256M RAM. This is plenty for a home PC, but a server works very hard and needs as much RAM as you can throw into it. Here, I am opting to add 1G of extra RAM to take it up to 1,256 megabytes.

Another reason for the extra cost of servers is that they usually use motherboards that can accept a second CPU. Using a Windows Network Operating System (like Windows 2000 Server) puts quite a processing strain on a server. The second CPU lets the server split its workload over two chips. To use the second CPU, the server's operating system must be able to support multiple CPUs. Some can, some can't. Make sure yours can before you spend nearly $2000 on a second CPU that might sit there uselessly!

Obviously, you need a power supply, but servers can be fitted with a second, redundant power supply. If one fails, as they sometimes do, the other takes over.

"Hot Swap" is a feature that lets you remove and insert devices like hard disk drives and tape drives without turning off the server. Sure, it would only take a few minutes to "down" the server, pull out a defective drive and install a new one, but servers can rarely afford to be "down". Hotswap lets you add or remove components without disrupting the network.

Naturally, you need a CD-ROM drive to install software onto the server.

This is the network card that a server needs to communicate with the network. The 10/100 means it is possible for the card to run at 10 or 100 megabits per second. You can optionally add on another network card to double this communication speed: the server can use both cards to shunt data in and out. An option is to go for a "gigabit" network card, which can communicate at a maximum of 1,000 megabits per second. Of course, it helps if the rest of the central network components are also high speed.

At McKinnon, all our switches are rated at 100Mbps. The servers are all plugged into one switch, which then feeds other switches that are either connected directly to workstations or feed another switch (which leads to workstations.)

Every server needs a tape backup drive. This one can store 40G. If you have more hard disk space than that, and it needs to be backed up, you may need to use more than one tape to complete a backup. Fortunately, if you are usually doing incremental backups - just saving data that has changed since the last backup - you are not likely to need more than one 40G tape.

RAID (Redundant Array of Inexpensive Disks) offers much improved data security. You can read more about it here. The controller can offer RAID0 to RAID5, depending on how many hard disks are installed in the server.

Notice two things: these hard disks are expensive, and there are 3 of them. The expense is due to their high performance (they spin at 10,000 RPM, which is a fair bit faster than the average home HDD). They are also hot-swappable, so they can be pulled out or inserted without disturbing the server's normal operation. There are three of them so I can use RAID5 for maximum data safety. Having multiple hard disks also offers greater speed, because if one disk is busy, one of the others can do the work.

Not having a UPS (Uninterruptible Power Supply) on a server is just plain silly. The UPS not only keeps the server working during blackouts, but also filters the current to reduce the chances of the system being damaged by power spikes or brownouts.

You look at the total price tag and you stagger backwards a bit, thinking "What the...??", but then you remember that this computer is the most important one in the whole network. If it dies, the network dies. If it's slow, the whole network is slow. If you need to save money, do it elsewhere on the network: don't scrimp and save on the file server. If you needed a heart transplant, would you choose one from a 98 year old chainsmoking alcoholic just to save a few dollars?