[net.micro.pc] Hard disk overhead?

forbus@uiucdcsp.UUCP (01/21/85)

When counting up the files used in the various directories on my
Compaq-plus, I found that a little over 3MB were accounted for.
Yet the checkdisk program claims that just over 7MB are in use,
with 28KB in "hidden files".  One might expect a little bit of
overhead for directory pointers and such, but this amount seems
absurd.  Does anyone have a theory that will account for the
discreprency?

rsellens@watdcsu.UUCP (Rick Sellens - Mech. Eng.) (01/22/85)

Re: 7MB to store 3MB of files

Under DOS 2.0 the hard disk is allocated in 4K blocks. This means that
no matter how small a file is, it will still take up 4K of disk space.
The dir command reports the logical length of the file, not the amount
of disk space allocated to it.

The result is that each file averages about 2K of unused, but allocated
space. The situation is far worse if you have many small files. (like
individual c function source code) I hear that DOS 3.0 allows you to
vary the block size when you format a hard disk, so you can decide what
is best for your own system.


Rick Sellens
UUCP:  watmath!watdcsu!rsellens
CSNET: rsellens%watdcsu@waterloo.csnet
ARPA:  rsellens%watdcsu%waterloo.csnet@csnet-relay.arpa

ee161abt@sdcc13.UUCP (Joseph B. Kornfrau) (01/24/85)

> When counting up the files used in the various directories on my
> Compaq-plus, I found that a little over 3MB were accounted for.
> Yet the checkdisk program claims that just over 7MB are in use,
> with 28KB in "hidden files".  One might expect a little bit of
> overhead for directory pointers and such, but this amount seems
> absurd.  Does anyone have a theory that will account for the
> discreprency?

Using DOS 3.0 on my 10MB, it seems that an extra 2048 bytes
(real or imagined) are being allocated PER FILE!  Personally,
these Microsoft fiascos are beginning to get to me.  Unless
somebody stops me, I'm switching to COHERENT.

forbus@uiucdcsp.UUCP (02/04/85)

Careful checking reveals that on COMPAQ's flavor of MS-DOS 2.0,
storage really is allocated in 4096 blocks as an earlier response
suggested.  Sigh.  Still, it beats time-sharing...