I tried this, but it didn’t work at all on my Thinkpad X230. I then tried changing some other options in the aforementioned file, but none worked, and surprisingly, Ubuntu even reported errors.

So, I reinstalled the more preferred Debian. Tried again, and it still didn’t work. Finally, I found a more brutal method.

systemctl mask sleep.target suspend.target hibernate.target hybrid-sleep.target

This directly points these units to /dev/null…

To revert, simply use:

systemctl unmask sleep.target suspend.target hibernate.target hybrid-sleep.target

It’s simple and effective.

Update:

If you only mask them, the CPU usage of systemd-logind will be very high because it continuously attempts to sleep. Therefore, you also need to change HandleLidSwitch and others to ignore. As follows:

HandleSuspendKey=ignore
HandleHibernateKey=ignore
HandleLidSwitch=ignore
HandleLidSwitchExternalPower=ignore
HandleLidSwitchDocked=ignore

Then, execute systemctl restart systemd-logind. For more details, refer to this: SystemD-LoginD High CPU Usage.

1. Disable SeLinux
   Edit the configuration file:

   vi /etc/selinux/config
   

   Modify as follows:

   #SELINUX=enforcing    # Comment out
   #SELINUXTYPE=targeted # Comment out
   SELINUX=disabled      # Add this line
   

   Then reboot the system:

   reboot  # Restart the system
   

2. Create a Directory
   Using the root user, create a directory named /nfs. Note: It’s best to check which partition has the most space by running df, as the root (/) partition may not have the most space. In some automatic partitioning setups, the /home partition may have the most space.

3. Install NFS Utilities and RPC Bind

   yum -y install nfs-utils rpcbind
   

4. Enable Services at Boot

   chkconfig nfs on
   chkconfig rpcbind on
   chkconfig nfslock on
   

5. Configure Exports
   Edit the NFS exports file:

   vi /etc/exports
   

   Add the following line:

   /home/nfs 192.168.1.0/24(rw,sync,no_all_squash)
   

6. Start NFS Services

   service rpcbind start
   service nfs start
   service nfslock start
   exportfs -a
   

7. Configure NFS Ports
   Edit the NFS configuration file:

   vi /etc/sysconfig/nfs
   

   Uncomment the following lines:

   LOCKD_TCPPORT=32803
   LOCKD_UDPPORT=32769
   MOUNTD_PORT=892
   

8. Restart NFS Services

   service rpcbind restart
   service nfs restart
   service nfslock restart
   

9. Verify RPC Services

   rpcinfo -p localhost
   

   Note down the ports and their types.

10. Configure Firewall Rules
    Adjust the IP range according to your network:

    iptables -I INPUT -m state --state NEW -p tcp -m multiport --dport 111,892,2049,32803 -s 192.168.0.0/24 -j ACCEPT
    iptables -I INPUT -m state --state NEW -p udp -m multiport --dport 111,892,2049,32769 -s 192.168.0.0/24 -j ACCEPT
    

11. Save Firewall Rules
    Test from the client side. If successful, save the iptables configuration:

    service iptables save
    

Client Side

1. Create Mount Point

   mkdir /nfs
   

2. Check RPC Services on Server

   rpcinfo -p [server_ip]
   

3. Show NFS Exports

   showmount -e [server_ip]
   

4. Mount NFS Share

   mount -t nfs -o soft,intr,bg,rw [server_ip]:/home/nfs /nfs
   

5. Unmount NFS Share

   umount /nfs
   

6. Configure Automatic Mounting
   Edit the fstab file:

   vi /etc/fstab
   

   Add the following line:

   [server_ip]:/home/nfs /nfs nfs soft,intr,bg,rw 0 0
   

Installed Version: CentOS 6.3

1. Using Win32DiskImager to create a USB flash drive image was unsuccessful; installing from an external USB optical drive was successful.
2. During the installation process, make sure to select the “Virtual Host” installation mode.
3. The rest can be set to default or slightly modified, such as choosing the time zone.
4. After installation, it will include the KVM suite and SSH.

Installation Notes

• No internet connection is needed throughout the process, which is much better than Debian and Ubuntu.
• You’re not forced to set up a non-root user.
• Before installation, be sure to check whether your CPU supports virtualization and enable the motherboard’s virtualization setting. If the motherboard supports virtualization but doesn’t have a virtualization option, you can still use virtualization as it’s definitely enabled by default. There’s a saying that Intel CPUs with a ‘K’ cannot perform virtualization. ‘K’ means Intel CPUs that can be overclocked. It seems that faster and newer CPUs are not necessarily better.