Occasionally you may forget your vCenter login password. If you are using the VirtualCenter Server Appliance (5.0 in my case) and fail three times (by default) then you’ll get locked out

 

To check this is the case. SSH (via root) to your appliance

Then examine /var/log/messages . I found this line:

Jul 11 14:49:50 jord-vcenter vpxd: pam_tally(vmware-authd:auth): user jordansphere (1005) tally 4, deny 3 

 

I then used the following command to double check it had been locked out:

# pam_tally –user jordansphere

 User jordansphere (1005)  has 4

 

To reset the counter:

# pam_tally –user jordansphere –reset

User jordanpshere (1005)  had 4

 

I’d also forgotten my password so had to reset it anyway!

jord-vcenter:~ # passwd jordansphere
Changing password for jordansphere.
New UNIX password:
Retype new UNIX password:

 

Edit: To alter the amount of deny attempts then edit the /etc/pam.d/common-auth file and change the value (3) to whatever you want.

auth      requiste    pam_tally.so deny=3