behavior of "df" under root and regular user

Justin Walker justin at Apple.COM
Wed Aug 8 02:05:53 AEST 1990


In article <3022 at dftsrv.gsfc.nasa.gov> jim at jagmac2.gsfc.nasa.gov (Jim Jagielski) writes:
> ...
>When run by root, df prints out the WRONG amount of free blocks... when run
>by a regular-dude, then the free block count os correct. When root runs, df
>adds back in the 10% that is used by the BSD file-system. This gives erroneous
>information, since (as far as I know) this space is NOT available for file
>storage...
	I believe that for BSD file systems, the kernel reserves 10% of the
	total block count for "root usage", so that regular-dudes cannot snarf
	up all the file system for their own nefarious uses (e.g., cat * > foo)
	and fowl up the system.  The space is available for file storage,
	but only for root's use.  This is not the case for SVFS types, where
	you regular-dudes can gobble to your hearts' content.

>           Jim Jagielski                    NASA/GSFC, Code 711.1
>     jim at jagmac2.gsfc.nasa.gov               Greenbelt, MD 20771

Regards,

Justin

Justin C. Walker, Curmudgeon-At-Large   (justin at apple.com) *
A/UX Group                              *------------------|
Apple Computer, Inc.                    |  When meetings are outlawed,
10440 Bubb Rd,                          |    Only outlaws will have meetings
Cupertino, CA 95014                     *
-- 
Justin C. Walker, Curmudgeon-At-Large   (justin at apple.com) *
A/UX Group                              *------------------|
Apple Computer, Inc.                    |  When meetings are outlawed,
10440 Bubb Rd,                          |    Only outlaws will have meetings
Cupertino, CA 95014                     *



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