Forcing root filesystem read-only during normal operation

["Ross Peachey" <Ross@ttpartners.com.au>]

Hi All,

Can anyone tell me how to force a filesystem read-only from Debian
during normal operation? I need to do this for testing of a failure
mode.

The following doesn't work:

* hdparm -r1 <device>
* mount -o ro,remount /

Also, the host is running as a Xen virtual machine, so I can't do
anything on the hardware side.

Given that the filesystem is set to remount read-only if an error is
detected, one option would be to deliberately generate a filesystem
error, but not sure exactly how to achieve this either.

Any pointers or assistance would be greatly appreciated.


Kind Regards,
Ross.