Mounting a protected directory.

I am trying to recover a lost password for a BIG-IP HA Load Balancer (D45), but when I try the "/sbin/mount -auw" I get this... "/dev/wd0g on /var: Specified device does not match mounted device." Is this because the machine has a protected file system? I have tried the "/usr/bin/passwd root" already but when I reboot the device, the Root password is not correct. Can anyone help here?