Chapter 3 - Lab: cgroup

Robson Esteves

Hi,

i'm running the chapter 3 Labs and in the CGROUPS Lab section, I can't find the package cgroup-tools. The message received indicates that was unable to locate the cgroup-tools after apt install cgroup-tools. Could you help me?

 

BR,

Robson

  

nkhare

Hi Robson, 

As mentioned in earlier comment sometimes you might need to update the package index with following command to refresh the package list :-

$ apt update 

Please run the above command and then try just installing "cgroups-tools" package. 

Thanks for reporting the issues. May be we should to add "apt update" instruction before installing any packages on Ubuntu 16.04. 

 

Thanks. 

Neependra

 

Robson Esteves

Done and solved! Thanks Neependra!

Robson

AlexeyBY

Hi all,

I'm doing the cgroups part of the labs.

Come back to the previous terminal and, in the tasks file, append the PID which we got in previous step:
$ pwd
/sys/fs/cgroup/freezer/mycgroup

$ echo 6664 >> tasks

The result of the "echo" is -->> "-bash: tasks: Permission denied". I tried with and without sudo.
I'm using my own Ubunty (not DigitalOcean) 16.04.6 LTS (Xenial Xerus) and 18.04.4 LTS (Bionic Beaver).

It's Ok to freeze the process on my CentOS7 !

Probably the root of the issue is Ubuntu where it's impossible to work under root....

Could you help me to solve the issue.
Alexey

chrispokorni

Hi @AlexeyBY,

Here is a link which explains how to use sudo to run commands as root, and how to use sudo -i to become root:
https://help.ubuntu.com/community/RootSudo
Once you become root, you should be able to run the echo ... command.

Another resource explains again how to run echo as root and with sudo:
https://askubuntu.com/questions/230476/how-to-solve-permission-denied-when-using-sudo-with-redirection-in-bash

Good luck!
-Chris

RachelChan

for the command 'apt install -y cgroup-tools', what does the -y flag do?

RachelChan

Nevermind- found it. The -y option assumes yes to all prompts.
http://manpages.ubuntu.com/manpages/bionic/man8/apt-get.8.html