linux stress, impose work on specific disks

Question

Have a server running centos 7.6, and it has 4 ssd's as Raid-0 mounted as /scratch/

I have the linux program stress-1.0.4-16 and I just learned stress-ng existed.

Is there a way with stress to tell it to do I/O operations to stress a specific set of disks such as my 4 disk Raid-0? Or does it only work on whatever the root file system is such as /tmp? And if that's the case I've done systemctl enable tmp.mount which means the /tmp folder is no longer on disk negating the disk i/o function of stress ?

Answer 1

You just need to cd to a directory in the disk drive you want to stress. Using -v option confirms it creates the stress files on the current directory.

# stress -v -d 1 
stress: info: [29736] dispatching hogs: 0 cpu, 0 io, 0 vm, 1 hdd
stress: dbug: [29736] using backoff sleep of 3000us
stress: dbug: [29736] --> hoghdd worker 1 [29737] forked
stress: dbug: [29737] seeding 1048575 byte buffer with random data
stress: dbug: [29737] opened ./stress.yPWMGk for writing 1073741824 bytes
stress: dbug: [29737] unlinking ./stress.yPWMGk
stress: dbug: [29737] fast writing to ./stress.yPWMGk

I also suggest you use fio instead if you need a more accurate tool.