Configure and Customize Dell PowerFlex v3.6.x

Change the GRUB template for Skylake/Cascade Lake CPUs

For Skylake CPUs or Cascade Lake CPUs throughput on PowerEdge 14G models running RHEL 7.2 or later, change the GRUB template on every node to ensure that the CPUs maintain good performance in terms of latency.

1. Open the GRUB template for editing:

   vim /etc/default/grub
   

2. Find the GRUB_CMDLINE_LINUX configuration option and append the following to the line:

   intel_idle.max_cstate=1 intel_pstate=disable

   Example:

   GRUB_CMDLINE_LINUX="crashkernel=auto rd.lvm.lv=rhel/root 
   rd.lvm.lv=rhel/swap rhgb intel_idle.max_cstate=1
   intel_pstate=disable quiet"

3. Compile the new GRUB:

   grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg

4. Stop and then disable tuned:

   systemctl stop tuned
   systemctl disable tuned

5. Run reboot to reboot the node.
6. Ping the node to ensure that the GRUB change was implemented.
   The ping time should be in the 0.03 ms range.
7. Repeat the procedure on every 14G node with a Skylake/Cascade Lake CPU.