Linux Server Overloading

Key Factors to Find Resource BottleNeck in Linux Server Overloading
By Asad Niazi

It's very common, despite of the affordable hardware, to have load issues on the server. There can be a number of reasons for high load on the server such as, inadequate RAM/CPU, slower hard disk drives, or just unoptimized software. This article will help you identify what's the bottleneck and where do you need to invest on. Please, however, do not take it as a replacement of professional advice/service. You should always seek professional service if you can afford the costs associated.

I) First of all, are you really in trouble?

Usually people look for load in control panels, using "uptime" or "top" command. You can probably execute the "uptime" command in your root shell to find out what's the load, but I would like you to use "top" for the moment (pretty please). This will help you identify how many CPUs are being reported*. You should be able to see something like cpu00, cpu01, etc. A load of ~1 for each cpu is reasonable. For example, you're fine if the load's 3.50 and you have 4 CPUs.

Another thing to consider while looking at the load via uptime or top, is to understand what it shows. For instance: (on a 2HT cpus server, reported as 4)

18:30:55 up 17 days, 5:17, 2 users, load average: 4.76, 2.97, 2.62

The first part (3.76) shows the load average in the last 5 mins, while the second (2.97) and third (2.62) shows averages of 10 and 15 mins respectively. It's probably a spike here which I wouldn't be too worried about (a bit carefree?), but if you are, then just read on!

Pretty happy about how you were able to identify that your server is really overloaded? Sorry to hear that, but you never know because sometimes servers are able to handle much more load than the load shown. The load averages aren't so accurate afterall and cannot always be the ultimate deciding factor. Confused? It was just some technical information you don't need to be so bothered about. Move ahead if your loads are something to worry over.