USB Booting vs Readonly FileSystem ?
 

Hi ,
Which of the live linux distro can boot from USB and mount its own usb files and folders as readonly file system ( ro ) ?

all live OSs are ro. that is why they are LIVE. now they will allow you to make "temporary" changes to those files, but when you reboot, those changes are gone. The reason they let you make temporary changes is if you wish to install from the LiveCD/DVD/USB those customizations will show in the now installed OS.

No , i tested more than 10 distro (knoppix,slitaz,zorin,slax,...)and when i boot them from USB they mounted my USB storage as RW ( Read & Write ) !
your reply will be right if these booted from CDROM not USB .

then im not following what you are asking, if you create a LiveUSB drive, that drive is exactly as I stated above. It is a Live OS. Nothing changes with a Live OS due to its media.

Now if you have additional USB devices connected to the computer running off of the LiveUSB, well then yes those will automagically mount rw. Same thing will go if you partition your USB drive to have the LiveOS boot from one partition and use persistent data for the rest of the drive, the other partition. that will be mounted rw.

I don't tell about additional USB drive !
All of Live Linux ( That i tested such as knoppix , slitaz , slax , ... ) When booted from pendrive USB , Mount its USB media as RW .
You could create an USB bootable Linux ( such as with unetbootin or pendrivelinux or ... ) and see that it mount its media file & folders ( /dev/sda1 ) as RW !
I wish i explained good my problem .