3.2. Optimizing Virtual Machines Running On Red Hat Gluster Storage Volumes

The readahead mechanism is essential for sequential read performance on virtual machines. For virtual machines that run on Red Hat Gluster Storage, the virtual-guest profile does not provide sufficient readahead by default. You can improve virtual machine performance by editing the virtual-guest profile to provide a more suitable readahead value.
  1. Install the Tune daemon

    Install the tuned daemon that tunes the system settings dynamically.
    # yum install tuned
  2. On the virtual machine, edit the virtual-guest profile

    In the /etc/tune-profiles/virtual-guest/ktune.sh file, change the value of the multiply_disk_readahead option to 16.
  3. Apply the modified virtual-guest profile on the virtual machines

    Activate the modified profile with the command:
    # tuned-adm profile virtual-guest