Could not open a session

[Robert Legatie]

$ su -
Password:
could not open session.

$ uname -a
Linux XXXXXXXX 2.6.18-128.el5

I am getting an error when I try to su to root or other users. I did check the /etc /etc/passwd /etc/shadow and /etc/pam.d file permissions.
$ ls -ld /etc /etc/passwd /etc/shadow /etc/pam.d
drwxr-xr-x 82 root sys 9216 May 17 09:29 /etc
drwxr-xr-x 2 root security 3072 May 13 13:07 /etc/pam.d
-rw-r--r-- 1 root root 24135 May 12 09:55 /etc/passwd
-r-------- 1 root root 13384 May 12 09:55 /etc/shadow

Can someone please help/advise??

Thanks.

[John Guster]

your "su - " means to root by default, is root account in the /etc/passwd?
the error suggests that the user account you try to become does not exist on the system, here is in the /etc/passwd.

[Ivan Ferreira]

You should post the content of your /etc/pam.d/su and /etc/pam.d/system-auth files. Also, what you get in /var/log/messages and /var/log/secure when you try to "su" to root.

Maybe you need to be member of the wheel group.

[Gerardo Arceri]

Check for resource exhaustion conditions, you might be running out of file descriptors and/or allowed processes.
Use ulimit to determine the current limits.