Enable CPU frequency performance mode

Enable cpu frequency performance mode: 

# on CentOS
yum install kernel-tools

systemctl start cpupower
systemctl enable cpupower

Other commands

# cpupower set performance mode
cpupower frequency-set -g performance

# check current cpupower mode
cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
performance

Refer to

• CPU frequency performance 
• Linux系统安装之后，如何调节CPU性能策略 
  

KVM on CentOS 7

Refer to 

• How to install KVM on CentOS 7 / RHEL 7 Headless Server 
• Install and Configure KVM (Bridge Net Interface) on CentOS 7 / RHEL 7 (KVM Bridge verified it work)
  

X11 forwarding on Windows with putty

Refer to 

Use Linux Graphical Softwares on Windows via X11 Forwarding 

Expand and Shrink LVM [cautious]

Be really careful and cautious when shrinking a LVM volume.

Refer to 

• How to Extend/Reduce LVM’s (Logical Volume Management) in Linux – Part II