Make disk completely read-only?

[Engineering]

On 07/24/12 18:06, Sam Zehr wrote:
>> Hi, this is Sam again, working on making a USB flash drive in FreeBSD 
>> 9.0 _completely_ read-only.
>>
>> Disk is mounted read-only - fstab has ro,noatime
>>
>> Following some advice from the list, I've done some binary compares to 
>> see what is going on. It looks like only a few bytes are changing 
>> every time I reboot, they seem to correspond with the superblock 
>> locations - I would guess a timestamp of mount time?

>Try adding this line to rc.conf:
>
>root_rw_mount="NO"

Thanks! That does the trick.
Sam