On Sun, 29 Nov 2009, Subodh Nijsure wrote: > I am experimenting with making USB parition true read-only partition. > I am mounting the device, with ext2 filesystem, as read-only. > > I am also marking the block device as read-only using the blockdev > utility from util-linux-ng, by using command blockdev --setro > path-to-block-device That should work. But it won't help if the writes already took place. > What I am finding is, if I use block device as raw input device, and > compute md5 checksum on the data read. The checksum's don't match from > mount to mount. > > I see that block #2, corresponding to super-block is getting updated, > but there is also one block on the device that gets updated within the > device. > > Is there a way to mark USB partition as true read-only partition? Only the ways you have already tried. Some USB devices have a switch you can use to make them read-only, but most do not. If you collect a usbmon trace, you'll be able to see when the writes occurred. That might help you to figure out what caused them. See Documentation/usb/usbmon.txt for instructions. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
