root user can do everything on a linux based system, if you can't change dir...

root user can do everything on a linux based system, if you can't change dir perms you're probably trying to do one of these things:
- change a dir located somewhere else in your network (an NFS network drive, CODA, or something like that)
- a virtual dir or a special part of the filesystem, you can see some dirs like /dev /proc and so on, these dir are special purpouse dirs and you can find hw related device names and memory mapping (like /proc)

Whan kind of file you're talking about ?

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