Messages in this thread | | | Date | Fri, 03 Dec 1999 16:47:40 +0100 | From | Klaus Espenlaub <> | Subject | Re: Can't hardlink in different dirs. (BUG#826) |
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On Fri, 3 Dec 1999, Andrea Arcangeli wrote:
> For what exactly is it an handy feature? I never needed to hardlink to a > file that I don't own, so you would convince me if you would raise good > points.
It's a handy feature to piss off other users when quotas are on the file system: you hard link every single bit they have in their home directory. The users vulnerable to this must have world/group access to their home directory, but most lame users have. A lame user won't notice that all his file have a link count of 2. From time to time he will delete files and create new ones (which you dutifully hard link). After a while he'll end up with an empty directory and still has his quota exceeded.
But don't do this if the system administrator is anyone else than your best buddy.
To be more serious: most of the time hard links between directory exist if users have a low quota and need programs that aren't installed system wide (usually for some reason). This way they share the size (I install program X, and you install program Y, and we add a few hard links here and there...). I know that the same goal can be achieved by using soft links, but they have the fame of having a large overhead. This is a point for NFS filesystems over a single 10Mbit ethernet with 40 diskless machines.
Then there are some ill scenarios where hard linked suid programs can be used if the admin is too lazy to create the desperately needed groups which would allow access to a common directory with the original files.
-- Klaus Espenlaub Email: espenlaub@informatik.uni-ulm.de Universitaet Ulm Phone: +49 731 50-24178 Abteilung Rechnerstrukturen Fax: +49 731 50-24182 D-89069 Ulm Office: Building O27, Room 316
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