You will often hear people quote that their network, service or server has an uptime of a certain percentage. However what does this actually mean?
Uptime is the amount of time that a particular service is available to the users. Most of the time you will have over 90% uptime - i.e. the service is available 90% of the time that the user actually needs it. However you should be aiming for closer to 99% uptime. While this may seem high, it is easily achievable. The table below shows how uptime percentages equate in to downtime allowed for routine maintenance.
The times shown are all the same, so 7 hours is equivalent to 420 minutes, which is 25200 seconds
| Downtime Per Month | Downtime Per Year | |||||
| Hours | Minutes | Seconds | Hours | Minutes | Seconds | |
| 99 | 7 | 420 | 25200 | 84 | 5040 | 302400 |
| 99.9 | 43 | 2580 | 8.6 | 516 | 30960 | |
| 99.99 | 4.4 | 265 | 52.8 | 3168 | ||
| 99.999 | 25 | 5 | 300 | |||
Collecting the Statistics
Some systems will have the uptime statistics built in, allowing you to just copy them off. For others you will need to use a utility.
For Windows servers you need to download a utility from Microsoft called uptime.exe .
Once you have this utility you can view a brief status of the current uptime, or run more thorough information which gives you the percentage uptime to 4 decimal places.
You can read more about the the uptime utility and download it from here: http://support.microsoft.com/default.aspx?kbid=232243.
While this tool was originally written for NT4 servers, it is fully compatible with the later servers including Windows 2003.
Web Page of Uptime Statistics using Windows Uptime Tool
You can make a web page with the uptime statistics of your servers, or embed the information in to another page.
The web page is made up of two parts
- A batch file to collect the statistics
- An ASP page holding the results.
Batch File
The batch file calls uptime.exe and drops the result in to a location where it can be picked up by the web server.
uptime.exe \\servername >F:\Web\status\servername.txt
(where F:\web\ is the location of the web site)
This batch file is scheduled to run every 10 minutes.
ASP Web Page
ASP file has lots of these:
<!--#include virtual="/status/servername.txt"-->
Where "servername.txt" is the result file from the batch file