thanks sysdev , but don't accept my root password !!!Wel, enter your root password and it wil drop you in a single-user shell.
Add 'init=/bin/sh' to your kernel boot parameters when booting. That wil give you a shell without asking for a root password.
Even though the system may look read-only after that, you'll still be able to run the fsck commands.
When done, remove the 'init=/bin//sh' from the startup parameters.