I have Linux Virtual machine (ubuntu 12.04) installed on my Mac OS.
On my terminal,
user@192.78.0.1:~$ su
password:
su : Authentication failure
user@192.78.0.1:~$ ls -lth /bin/su
-rwsr-sr-x 1 root root 36K Sep 12 2012 /bin/su
But the following works:
user@192.78.0.1:~$ sudo ls
[sudo] password for user:
(....lists the directories)
user@192.78.0.1:~$ sudo -s
[sudo] password for user:
root@192.78.0.1:~#
Hence the question is,
why sudo -s
works and logs in as root, while su
results in authentication failure.
I typed the passwords correctly each time.
Also sudo ls
works