Problem with k3b in 18.04 releases " cdrecord has no permission to open the device"

Question

I have this problem with k3b in 18.04 releases (Ubuntu, Kubuntu, KDE Neon...) In oldest releases I do not have this problem:

cdrecord has no permission to open the device
You may use K3bbsetup to solve this problem. 

I've searched online but I have not found any solution.

Can anybody help me?

Solution

Try attempting the following commands:

sudo chmod 4711 /usr/bin/wodim; sudo chmod 4711 /usr/bin/cdrdao

This will set the UID bit on the necessary binaries. It is illustrated in Settings -> Configure k3b -> programs -> Permissions "tab".

Comments

[louiesanchezdj]

Now I use Ubuntu 18.04, but I have the same error. I could record with k3b running it as superuser, (sudo k3b), but I do not like to run programs like root, because it can generate various problems. In my Linux Mint 18.3 or in my Debian 9 I do not have this problem.

[NicolasSmith]

Works fine with Ubuntu Mate 18.04, I can now erase disc-rw with k3b. Could you more explain the commands chmod and 4711 ?

[Nico R]

chmod controls the permissions of the file. The four numbers (in this case of an executable file) mean: 4: If a user executes the file, it will be run in in root's context instead of the current user's, since only root can access /dev files writing, which is needed for CD/DVD recording 7: the user who owns the file (in /usr/bin usually root) is allowed to execute, modify and read the file 1: the file's assigned group (in this case root as well) is only allowed to execute it 1: all other users are only allowed to execute See also en.wikipedia.org/wiki/Chmod#Numerical_permissions

[Admin]

This applies to other Linux distorto too.