Stress is a workload generator for linux operating systems. It allows the user to configure the amout of CPU , memory, I/O and disk stress to be applied on the linux system. Below example shows you how to create a load of 4 on the linux system.
Note : You need to use this tool wisely, a huge workload created by stress might render the system unusable resulting in force reeboot of the Linux system. You might also need to change the configurations depending on the hardware capability.
The below example puts a load average of 4 on the linux system.
# stress --cpu 2 --io 1 --vm --vm-bytes 128M --timeout 10s --verbose
For downloading and more information on stress, click here