On 05/01/2014 01:31, Chris Stankevitz wrote: > On Thu, Jan 2, 2014 at 10:45 PM, Alan McKinnon <alan.mckin...@gmail.com> > wrote: >> You don't need chown/chmod at all. FAT has no concept of owner and >> permissions, so the kernel fudges these. Basically, when mounting the >> stick it pretends every file on it is owned by the user that mounted it >> and everything has permissions 777, regardless of who plugged it in. >> Considering the nature of a USB stick, this is almost always what you want. > > Alan, > > Thank you very much this is exactly what I needed to understand. It > sounds like trying to manage a shared disk/stick with ext* would be a > PITA.
yes, it is, very much so FAT was designed for MS-DOS where you put a floppy in the drive and you had full access to everything on it. There was no need to implement security. And usually this is exactly what you want for USB sticks. ext* and all the other Unix filesystems were designed to cope well with multi-user, multi-process environments where the disk is fixed and a permanent part of the computer infrastructure. Security was very much part of the design. (OK, to be truthful in the early days it wasn't security, the idea was just to let everyone keep their stuff separate and not have everyone clobber everyone else's files, but that translates directly to a security model). In almost all cases this is not what you want for USB sticks. If you DO need security like eg sharing top-secret marketing strategy docs with the CEO :-) then you just encrypt the drive with a shared secret. There are many such packages out there, pick one that encrypts the entire disk without needing to know the fs structure underneath. But somehow I don't think *that* is what you are looking for :-) -- Alan McKinnon alan.mckin...@gmail.com
