Add in additional OS optimizations

[drikster80]

Based on the Nvidia Grace Performance Tuning Guide, implement optimizations.

Optimizations:

1. MTU to 9216 on interfaces
2. Disable irqbalance service: systemctl disable irqbalance
3. IOMMU

vim  /etc/default/grub.d/iommu_passthrough.cfg 
GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX iommu.passthrough=0 init_on_alloc=0"
update-grub
reboot

4. NUMA balancing setting (echo "kernel.numa_balancing = 0" >> /etc/sysctl.conf)
5. Set swap file size of 24GB - 48GB
6. cpupower frequency-set -g performance

[drikster80]

1,2, & 4 have been completed in 4589e2.

Need to test updating the cmdline and power frequency.