[comp.sys.apollo] DN1000 vs DN3500 file size

roode@hydra.cf.uci.edu (Dana Roode) (08/23/89)

We have a DN10000 running SR10.0 and a DN3500 running SR10.1.  Why does a
file occupying 992 blocks (according to ls -s) on the DN1000 take only
247 blocks (also according to ls -s) when copied to the DN3500? 

 Dana Roode
 UCI

krowitz@RICHTER.MIT.EDU (David Krowitz) (08/23/89)

Hard to say why, but ... what does ls -l say the sizes are? 
If the sizes reported by ls -l match, and the number of blocks
used reported by ls -s is less than you would expect given
the size, then I would guess that the file is probably being
stored as a "sparse" file. I don't have a lot of info on
these files offhand, but when we write a data file that has
a lot of zeros in it the file system seems to be able to
compact the file quite a bit. Try doing a diff on the two
files. If they come out the same, my guess would be that
the file system compacted the file when it copied it.


 -- David Krowitz

krowitz@richter.mit.edu   (18.83.0.109)
krowitz%richter@eddie.mit.edu
krowitz%richter@athena.mit.edu
krowitz%richter.mit.edu@mitvma.bitnet
(in order of decreasing preference)

zeleznik%cs.utah.edu@wasatch.utah.edu (Mike Zeleznik) (08/24/89)

In article <2535@orion.cf.uci.edu> roode@hydra.cf.uci.edu (Dana Roode) writes:
>We have a DN10000 running SR10.0 and a DN3500 running SR10.1.  Why does a
>file occupying 992 blocks (according to ls -s) on the DN1000 take only
>247 blocks (also according to ls -s) when copied to the DN3500? 
>
> Dana Roode
> UCI

Our 10K bsd4.3 du returns 4X the space that either /com/lst or /com/ld -a
(and adding them up) do.  I think ls -s returns the same as du (4X).  

I was told this was a problem in 10.0, but was fixed in 10.1, but we have
10.1 and still see it.  Our 10.1 is dated May 8, 1989 (bldt).

The version of du (from ts) which works CORRECTLY (our local office has it)
seems to be Feb 6 1989, 14:00:33. The version WE have is something like
10/5/88.  

Mike

  Michael Zeleznik              Computer Science Dept.
                                University of Utah
  zeleznik@cs.utah.edu          Salt Lake City, UT  84112
                                (801) 581-5617

stealth@caen.engin.umich.edu (Mike Peltier) (08/27/89)

In article <2535@orion.cf.uci.edu> roode@hydra.cf.uci.edu (Dana Roode) writes:
>We have a DN10000 running SR10.0 and a DN3500 running SR10.1.  Why does a
>file occupying 992 blocks (according to ls -s) on the DN1000 take only
>247 blocks (also according to ls -s) when copied to the DN3500? 
>
> Dana Roode
> UCI

The manual page for 'ls' indicates that the -s option prints the size
of the file in kilobytes.  A file containing "This is a test." showed
up as " 16 -rw-r--r--" on our DN10k, but as "  1 -rw-r--r--" on a DN3.5k.
I think I recall this having something to do with bigger block sizes
on the 10k -- 16kbyte blocks rather than 1kbyte blocks?  That would be
the natural conclusion given the above information...

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Michael V. Peltier         | Computer Aided Engineering Network      
1420 King George Blvd.     | University of Michigan,  Ann Arbor       
Ann Arbor, MI  48104-6924  |    stealth@caen.engin.umich.edu          
-- 
-	-	-	-	-	-	-	-	-
Michael V. Peltier         | Computer Aided Engineering Network      
1420 King George Blvd.     | University of Michigan,  Ann Arbor       
Ann Arbor, MI  48104-6924  |    stealth@caen.engin.umich.edu