Cannot open module /usr/lib/security

Dear All
After powering on my Netra120 Solaris server and waiting for all of the installed processes to be started , when trying for login I am getting :
"can not open module /usr/lib/security/pam_authtok_get.so.1"
Can you please let me know what has happened to my server and how can I reach the admin prompt to continue further to use the installed application server?
Thank you in advance

If pam isn't working you will have a hard time logging in the usual way. It's hard to tell what has happened, but any sort of disk or mounting problem which would prevent access to /usr/lib/ would cause it.

You may need to boot your system into single user mode.

Thank you very much for your reply . When I try to power off the server through its power on key the LOM prompt is available . Can you please let me know how to switch to single user mode on my Netra120 server while I cannot login to server to issue any command but just the LOM commands ?
Thank you for your time and attention in the matter

Single user mode:

Use DVD install media and

 
 ok> boot cd -s
 

In single user you should be able to mount your hard disk root filesystem and examine it.