Images, operating systems and headaches: The realities of security systems running on PCs

Security project designer and consultant Sean Ahrens examines the hang-ups of PCs that can give you IP video headaches

Computer Environment

You would not want to work in a dusty, dingy, hot environment, so what makes you think a computer will want to work there? Out of all of the technical surveys I conduct, you know what I write about 90 percent of the time? Dust! This is a big concern; dust causes problems, it insulates equipment, it restricts airflow by reducing the amount of airflow a fan can produce and more importantly it can create an opportunity for a ground fault or short. In the most literal term, a ground fault or short is an unexpected path of electricity. This, as you can imagine, is not good thing, and will most likely trash your whole computer. There's no BSOD; there's nothing. The computer will just turn off, and you will be left with a blinking cursor at best. The best option is to place the computer in an environmentally controlled location. Cleaning and maintenance will minimize the potential for an unnecessary failure.

Computer Maintenance

There are two type of maintenance that needs to be regularly conducted, one is hard-drive maintenance and the second type of maintenance is physical maintenance, such as dusting. I also regularly eliminate the computer's temporary cache and cookies. I also clean the computer 'registry'. The registry within Windows is essentially the traffic cop for the computer; it tells the computer what has been installed and how everything fits together. However, when you uninstall programs, remnants or links to those programs may still reside on the computer. The program is no longer functional, but still may draw processing functionality from the computer. A clean registry helps this.

Disk maintenance is also a must for non-RAID hard drives. Drives are used to store and access data, and are logically formatted. However, after time, data can become fragmented or disorganized on the drive in a way that may make the computer work harder to find files or programs. Disk maintenance in the form of "defragging" is highly recommended. In addition to defragging, I recommend you utilize software to identify a hard-drive failure prior to its occurrence. Over time, as the moving parts on hard-drive wear, there are subtle changes in the performance of the hard drive. There is software, usually free, which will help you identify a potential drive failure before it occurs. These maintenance tasks aren't always the easiest, so it's best to reach out to your IT department for direction and assistance in performing these tasks.


We have discussed precautions to preventing a failure, but unfortunately failures will inevitably occur. Organizations that rely heavily on surveillance systems need to develop continuity planning policies and procedures which address the loss of the surveillance system either in part or wholly as a result of a network or computer failure. The organization, as part of this continuity planning, should establish when back-up computers are required and how many spare computers could be needed. This will all be affected by the manufacturer and their software capabilities, or their lack thereof.

Ideally, an organization will identify how they will deal with a failure. The response will differ depending on the value and importance of the video system. One solution might be the use of a "hot" back-up computer; this is a back-up computer that is constantly running. The hot back-up takes over upon the failure of the primary computer. This computer is fully equipped and from a software perspective, it is a complete mirror copy of the primary computer.

Outside of a hot-back-up, organizations may rely on "cold" back-up computers or disk images. The data on a cold back-up computer or image may not be as current, but could be used in the interim, while the primary computer is repaired. One type of a cold back-up is the "imaging" of a computer. Imaging requires specialized software and takes a "snapshot or "image" of how the computer was configured at a specific time. This image is complete; it contains everything on the computer when the image was taken. This allows someone to restore a computer very quickly with everything that was on the computer at the time of the image.