[LUNI] Where is my data hiding??

[Gerald Guglielmo]

Hi,
  I am no expert in these matters but I have run into problems in the
past where "du" apparently under-reported the actual usage. At least
that was what the experts told me. In my case I was using an area in afs
space and "du" and "fs listquota" reported very different usage results.
The claim was that the "fs" was more accurate. Here is an idea of how
large that difference was:
> du -k -s .
  161576       .
> fs lq
  Volume Name                   Quota      Used %Used   Partition
  room.gug                     300000    270938   90%<<       56% 
<<WARNING
So the difference between "du" saying 7 and "df" saying 8 seems small in
comparison. I don't know what du is failing to take into account, but I
think that lots of very small files enhances the difference.

Martin Maney wrote:
> 
> On Fri, Mar 22, 2002 at 12:18:23PM -0600, Jay Strauss wrote:
> > I don't get this, I have an 80Gb drive, df shows its almost filled, but du
> > only says I'm using ~7Gb
> >
> > [root at meir /]# df
> > Filesystem           1k-blocks      Used Available Use% Mounted on
> > /dev/hda2              8475600   7917584    127476  99% /
> > /dev/hda1                46636      6077     38151  14% /boot
> 
> It's all right there: df says you have about 8G in them there partitions.
> 
> This may be a case of running into the 8GB limit, one of many breakwaters
> above the 512MB line where the traditional BIOS and IDE controller
> addressing fields don't have enough bits in common to directly address all
> the blocks.  8GB is usually the size all drives larger than that size report
> to the BIOS, but Linux is usually capable of seeing the drive's real size.
> So perhaps you're hitting a side effect of the 32GB truncation - 80 modulo
> 32 isn't quite 8, but then the count isn't in binary KB anyway, so that
> could be it.
> 
> OTOH, you just might have one of those self-consuming disk drives.  taht
> would be very bad, and you wouldn't want to have it in the system with any
> other drives; after it has consumed all of its own free space, it will start
> in on any other drives in the system.  Perhaps it would be best if you sent
> it to me for investigation and safe disposal, eh?  :-)
> 
> --
> The people who are serious in the open source world
> don't really think that making money is an evil process.
> Not even Richard Stallman.  Where you get that from is your
> cliche 12-year old on Slashdot who doesn't understand it. -- Bruce Perens
> 
> ______________________________________________________________________
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-- 
-Jerry->
gug at fnal.gov
Pepe's Theory of everything: "Under the right circumstances, things
happen."