How to Calculate Disk Busy Time and Disk Queue length in mandriva Linux ?

[vISHaTAN]

Hi, I have subject called Linux in my syllabus and in that we have different queries, among them two are like I have mentioned in the title as how can we calculate the disk busy time and disk queue length in the mandriva Linux OS? I know about the file called /proc/diskstats which will give me the input output statistics, rather than giving that it is returning the raw value only, so is there any way through which we can calculate those values from the this RAW values. Any suggestion?

[DanielV]

The term that you have mentioned that’s disk queue length is more associated with the windows rather than Linux, and this information you can get easily in the windows but for the Linux you have to use some of the third party tools, and I have heard about the iosts, you can download that tool and can get all the useful information, and you can easily get this tools from the internet itself.

[Enriqueta]

The file that you have mentioned in the problem that’s the diskstst in that you’ll get eleven different fields giving different result, and among them all are the important but if you see at the tenth field, the result of that is resulting of the time spent doing the I/O, so that is the time actually that is spent during the operation. And for that particular time you can say that the disk was busy.

[SalVatore]

I would say Average disk Queue Length is one of the major contradict. And you can find the length of any particular application only, but you haven’t mentioned anything about that. and for that you need to calculate the performance like for example if you have an array of 7 disks, and the Average Disk Queue Length is 20 for a each respective array, then the actual Average Disk Queue Length for each drive is 2.85.

[Ekpah]

The disk queue length is the value of a product of Disk Transfers/sec (response X I/O) and Average Disk sec/Transfer. You can use the software called process explorer that you can use to get all this information, and through that we can see which programs have the maximum I/O reads and writes. And If you don’t know about this program you can use another program too called fileMon. Using this software we can simply see every application being right to use on the machine in real-time.