Avamar: Unable to change users to root, su command fails with "su: /bin/ksh: No such file or directory"

When attempting to elevate from the admin user to the root user via 'su -' the command does not work and returns the following message:

"su: /bin/ksh: No such file or directory"

This is caused by the korn shell not being present in v7.3 of Avamar, and the root account being set to use it by default in /etc/passwd.

To confirm, check the shell that is currently being used by root.

We can do this with the getent command from the admin account (which works when run from any account).

Unexpected response (indicates an issue):
Expected response (normal output):
As we can see in the outputs above, avamar2 reports that the root user is set to use the korn shell. This is a problem, as the korn shell is not present in version 7.3.

The root cause of the issue appears to have been that the /etc/passwd entry for the root user was modified by someone after Avamar was installed

As we are unable to edit any root preferences using sudo in v7.3, we need to log into the root account to make changes. So we need to use the --shell=/bin/bash flag with the su command to override the default shell specified by /etc/passwd and use the bash shell instead.

The following two commands when run will accomplish this, first accessing the root account and then changing the default shell for the root account back to /bin/bash.