RHCSA Rapid Track

From workstation, open an SSH session to serverb as student user. The systems are configured to use SSH keys for authentication, so a password is not required.

[student@workstation ~]$ ssh student@serverb
...output omitted...
[student@serverb ~]$ 

Use yum to confirm that the tuned package is installed.

[student@serverb ~]$ yum list tuned
...output omitted...
Installed Packages
tuned.noarch                    2.10.0-15.el8                    @anaconda

Use the systemctl is-active tuned command to display the tuned service state.

[student@serverb ~]$ systemctl is-active tuned
active

List all available tuning profiles and their descriptions. Note that the current active profile is virtual-guest.

[student@serverb ~]$ sudo tuned-adm list
[sudo] password for student: student
Available profiles:
- balanced               - General non-specialized tuned profile
- desktop                - Optimize for the desktop use-case
- latency-performance    - Optimize for deterministic performance at the cost of
                           increased power consumption
- network-latency        - Optimize for deterministic performance at the cost of
                           increased power consumption, focused on low latency
                           network performance
- network-throughput     - Optimize for streaming network throughput, generally
                           only necessary on older CPUs or 40G+ networks
- powersave              - Optimize for low power consumption
- throughput-performance - Broadly applicable tuning that provides excellent
                           performance across a variety of common server workloads
- virtual-guest          - Optimize for running inside a virtual guest
- virtual-host           - Optimize for running KVM guests
Current active profile: virtual-guest

Change the current active tuning profile to the balanced profile.

[student@serverb ~]$ sudo tuned-adm profile balanced

List summary information of the current active tuned profile.

Use the tuned-adm profile_info command to confirm that the active profile is the balanced profile.

[student@serverb ~]$ sudo tuned-adm profile_info
Profile name:
balanced

Profile summary:
General non-specialized tuned profile
...output omitted...

Determine the top two CPU consumers on serverb. The top CPU consumers are listed last in the command output. CPU percentage values will vary.

[student@serverb ~]$ ps aux --sort=pcpu
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
...output omitted...
root      2983  100  0.0 228360  1744 ?        R<   21:08   0:23 md5sum /dev/zero
root      2967  101  0.0 228360  1732 ?        RN   21:08   0:23 sha1sum /dev/zero
[student@serverb ~]$

Identify the current nice level for each of the top two CPU consumers.

[student@serverb ~]$ ps -o pid,pcpu,nice,comm \
$(pgrep sha1sum;pgrep md5sum)
  PID %CPU  NI COMMAND
 2967 99.6   2 sha1sum
 2983 99.7  -2 md5sum

Use the sudo renice -n 10 2967 2983 command to adjust the nice level for each process to 10. Use PID values identified in the previous command output.

[student@serverb ~]$ sudo renice -n 10 2967 2983
[sudo] password for student: student
2967 (process ID) old priority 2, new priority 10
2983 (process ID) old priority -2, new priority 10

Verify that the current nice level for each process is 10.

[student@serverb ~]$ ps -o pid,pcpu,nice,comm \
$(pgrep sha1sum;pgrep md5sum)
  PID %CPU  NI COMMAND
 2967 99.6  10 sha1sum
 2983 99.7  10 md5sum

Exit from serverb.

[student@serverb ~]$ exit
logout
Connection to serverb closed.
[student@workstation ~]$