Simulate System Load

We often need to discover how the performance of an application is affected when the system is under certain types of loads. This means artificial load must be re-created.

Before that, I need to address the difference between /dev/zero and /dev/null, /dev/zero produces a continuous stream of NULL(zero value) bytes while /dev/null produces no output. So, we could say we use /dev/zero to create dummy files or swap.

Disk

We will create disk I/O by firstly creating a file, and then use a for loop to repeatedly copy it.

1. Generate a 1GB of file

   dd if=/dev/zero of=file bs=1M count=1024
   

2. a loop that runs 10 times

   for i in {1..10}; do cp file file1; done
   

The orginal post also mention how to drain CPU and RAM. link