Hard disks and network attached storage
Originally published in GP magazine .
Written for GP magazine around 2005. This is the version I submitted - the published article may have been edited.
Most people are familiar with the fact that a computer has a hard disk in it that stores information. Standard computers usually have one hard disk, though there are several reasons for wanting more than one. If you are running out of space, adding another disk can give you extra room to store information.
There are also a couple of clever things that can be done with a system called RAID, which is a means of linking disks together. In one type of RAID the same information is stored on two disks so that they mirror each other, and if one fails the other is available for use. This is costly, as you don’t get any more storage space for the cost of the second disk. There is another level that uses three disks; the third disk keeps tabs on the first two and helps recreate any missing data should there be a crash. Another RAID system speeds up disk accessing, as data being saved to the disk is split between two so it can get stored twice as fast. This method gives a doubling in speed and size; however, if one disk crashes both are lost, so it can be risky. RAID, however, isn’t that easy to set up if you don’t know what you are doing.
If your PC only has one disk and you are worried about losing information, there are several ways of keeping the data safe. At a practice you may have a tape drive that backs up all data overnight; however, these are expensive for personal use and can be a pain to use. The easiest option is to have an extra hard disk and some backup software that copies all your important files onto it at regular intervals.
You could fit the disk internally if the box is big enough, and while it isn’t that difficult it does involve screwdrivers and looking for jumpers (little electrical switches) to change. To make life easier, external hard drives are available that run off separate power supplies and connect direct into the computer using either a USB, FireWire or SATA port.
All PCs less than five years old will have a USB port. If you use a video camera or similar you may have a FireWire port, as they were originally designed to be faster than USB for large amounts of data. SATA is a much newer type of port that is specifically for hard disks, and I haven’t actually seen a machine with one yet.
A lot of companies have USB hard disks available in different sizes with different software, and pricing is very reasonable. Unless you have real reasons I would go with that rather than the others, particularly as should anything go wrong with the machine you can then simply plug it into another PC and read the data.
In a home network you may want to get more advanced. My house, unsurprisingly, is full of computers. Both my sons have computers, I have two and a laptop, and we are even thinking of giving Zedder our dog a computer so he can email us when he wants to go for a walk. We all want to share our music files and back up our computers. It would be wasteful to have a USB hard disk each. Using Windows file and printer sharing, if I have a USB hard disk connected to my computer all the others can see and use it. However, it slows my computer down and it has to be left on at all times.
This is where a special type of hard disk called a network attached storage device comes in. Traditionally networks have used a server for storing central information. However, for a home network this isn’t necessary, as the router/modem will handle access to the internet and many people don’t need the advanced features a server gives. One option is to use an old machine that is lying around as a cheap server. However, old machines can be liable to break and they don’t necessarily have a big fast disk in them, and though you could upgrade, there are other options for the same price.
A NAS is a hard disk that will plug directly into your network, usually via the router or switch. It doesn’t need to be connected to a computer, or have a computer on, to work. It is capable of being seen and accessed by all the computers on the network and can be used to share files and for backing them up.
Prices range from £100 upwards. Some use security to allow/deny access to different users, and some makes go one step further and allow access to the hard disk from the internet. This means you can access your data at work if needed, though when I have looked into this it can be difficult to set up.
Business-sized network disks are available, and some even run a custom version of Windows and are effectively a mini server. More recently, home products have become available that have both USB and Ethernet ports on them and can be used as a personal disk or as a network disk.
Netgear has a router with a port that allows normal USB hard disks to be used as a network disk, and if you already have a USB device and a router, Linksys has a box that allows you to connect your USB disks to the network.
How does all of this relate to my surgery? Although you should leave your clinical server to the supplier or PCT, many people have a second server to store intranets or shared data on, and NAS machines can be a lot cheaper than new servers and much easier to install.