VxFlex OS performance fine-tuning
Change the GRUB template for Skylake CPUs
Dell EMC VxFlex Ready Node AMS User Guide
122
Fine Granularity is being used and more performance per node is required, type the
following:
scli --set_performance_parameters --all_sds --tech --
sds_number_os_threads 12
Note:
To make these changes persistent after reboot, either create a script that
runs on boot, or change the kernel default scheduler via kernel command line.
For Skylake GPUs 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.
Procedure
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 CPU.