A FAQ regarding defrag and permissions of nonadmin files?

[Brian Dessent]

Gmane User wrote:

> Let's make sure we're comparing the same situation.  I've used bash to
> explicitly change permissions to go-rwx for most of my files.  This is

To be pedantic, you used chmod (or some other utility); bash is just a
shell, it does not set permissions.

> on a nonadmin account.  This is what chokes the defragger.  Do you
> have the same circumstance?

Yes, I just ran the series of commands in the previous mail as a
non-administrator user, creating a file in 2 fragments.  I then switched
to a user in the administrators group and ran O&O defrag (though the
user that launches the job shouldn't matter as O&O runs decoupled as a
service anyway) and the file was defragmented.

Note that Win32 has a backup API which allows any user with the 'backup'
privilege in their token to open any file, regardless of its ACL. 
Cygwin uses this to simulate the unix semantics of "root" (i.e. total
access to anything regardless of permissions) and so for example the
file I created with mode 600 as a regular user was completely readable
from Cygwin when logged in as a user in the administrators group, even
though the permissions/ACL deny it.  I suspect that O&O and most other
defrag programs use this same technique. 

Brian

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