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LFS201 Lab 15.1 Comparing I/O Schedulers.

MarkHeathcote Posts: 1
edited August 2020 in LFS201 Class Forum

Hi, I'm not sure of the workflow for getting the lab.iosched.sh script to run for this lab.

Im using Ubuntu 20.4 and the command to use was;

$ sudo ./lab_iosched.sh [# reads/writes (NMAX)] [file size in MB (NMEGS)]

How do I get the file into a place where Linux knows where to find it and run it?


  • heiko_s
    heiko_s Posts: 99

    Probably chmod +x lab_iosched.sh will do.

  • Note: we worked this in the Office Hours session. Need to do just 'sudo ./lab_iosched.sh' for starting. doing 'less lab_iosched.sh' will provide more information about the parameters.


  • coop
    coop Posts: 843

    Yes, you will have to make it executable probably if you downloaded in place. If you got from the "SOLUTIONS" tar ball it already is executable. Your results will depend on distro and kernel. For example I just ran it on Ubuntu 20.04 and the only IO schedulers were "mq-deadline" and "none". On RHEL 8 you have also "bfq" which is actually the default, at least for a vanilla kernel.

  • heiko_s
    heiko_s Posts: 99

    Mark: You mentioned during the office hour that you didn't manage to set sudo permissions for your default user. I sent you a private message with examples for /etc/sudoers and /etc/group configurations.


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