Path: utzoo!attcan!uunet!mcsun!mcvax!dik
From: dik@cwi.nl (Dik T. Winter)
Newsgroups: comp.os.aos
Subject: Re: How to find *real* file sizes in AOS/VS...?
Message-ID: <8416@boring.cwi.nl>
Date: 22 Sep 89 00:09:10 GMT
References: <1702@murdu.oz> <116@harald.UUCP>
Organization: CWI, Amsterdam
Lines: 22

About getting the disk space used by a specific file.

In article <116@harald.UUCP> jba@harald.ruc.dk (Jan B. Andersen) writes:
 > I think it's impossible, but you can get pretty close by DUMP'ing the
 > files to disk and then check the size of the dumpfile. The overhead is
 > only for the filename, the ACL, time and date etc.
I would think that a dumped file might use more space than a file that is
not dumped!  The previous poster alluded to compression techniques where
large blocks of 0's were not written to disk.  They might very well expand
when dumping in AOS (I do not know).

Anyhow, there are many OSes were it is impossible to obtain the number of
disk blocks used by a specific file.  E.g. under Unix (is this heresy?)
it is possible to create a file were ls (list files) gives a size of
several hundreds of megabytes and du (disk usage) on the directory reveals
that only 2 blocks are used.  (And of course under Unix it is possible that
the file that uses most space on the system is invisible because, although
it is still open, it is already unlinked!)
-- 
dik t. winter, cwi, amsterdam, nederland
INTERNET   : dik@cwi.nl
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