AMDGPU-PRO 17.40 install

[mccuerc]

I have installed the driver by adding LinuxMint to the install script. Then that followed the support page script perfectly. See: support.amd.com/en-us/kb-articles/Pages/AMDGPU-Pro-Beta-Mining-Driver-for-Linux-Release-Notes.aspx

The issue I now have is enabling "Large Page Support". It requires the following per AMD support page:

Ubuntu 16.04 LTS
a. Edit /etc/default/grub as root and modify GRUB_CMDLINE_LINUX_DEFAULT in order to add "amdgpu.vm_fragment_size=9" (without the quotes). The line may look something like this after the change:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash amdgpu.vm_fragment_size=9"

I can find Grub and I can modify it in text editor but I can not save the file. I receive

You do not have the permissions necessary to save the file. Please check that you typed the location correctly and try again

Suggestions as to how to proceed are requested. I am not an expert. Many thanks in advance.

LinuxMint 18.2
kernel 4.8.0-53 generic
celeron CPU G3930
8 GB ram
120 gb ssd
2x XFX RX570

[WharfRat]

Hello mccuerc

Welcome to Linux Mint and the Linux Mint forum

In order to edit that file and save it you need escalated privileges so just use gksudo xed /etc/default/grub

[mccuerc]

Double Plus Thanks for the solution.