From:	mharris AT blackwidow DOT saultc DOT on DOT ca
Date:	Thu, 30 Jan 1997 05:02:58 -0500 (EST)
Reply-To:	mharris AT blackwidow DOT saultc DOT on DOT ca
To:	"DR. Andras Solyom" <solyom AT eik DOT bme DOT hu>
cc:	djgpp AT delorie DOT com
Subject:	Re: 400 MB of my HD is missing
In-Reply-To:	<32EF3A32.101A@eik.bme.hu>
Message-ID:	<Pine.LNX.3.95.970130045717.190B-100000@capslock.com>
Organization:	Total disorganization.
MIME-Version:	1.0

On Wed, 29 Jan 1997, DR. Andras Solyom wrote:

> The reason lies in Dos's 16 bit FAT system. You can have less than 65535
> units (called clusters) on the HD. So the bigger a HD gets the bigger
> will be the clusters. On the other hand, sector size is 512 bytes in all
> these cases. Here is a simple table:
> 
> HD Size     Minimum required cluster size       Space wasted (%),
> average
>  Mbytes           (sectors/kbytes)
> 16-127 Mb         4/2                              2
> 128-255           8/4                              4
> 256-511          16/8                             10
> 512-1023         32/16                            25
> 1024-2048        64/32                            40
> 
> If you use Norton's FS (file size) command you can find out that those
> 400 Mbytes are wasted, because every file must occupy at least one
> cluster, even when that cluster stores only 1 data byte. Try to
> repartition your disk (you can do it without loosing any data with e.g.
> PartitionMagic from Powerquest. I bought it and use it succesfully).

These figures tie VERY closely to my own figures.  Most new computers
come with HD's > 1G.  Almost ALL of them are formatted to 1 partition.
The FIRST thing you should do when you get a new computer is:

1) Run UNDELETE or UNERASE to get some cool diagnostics programs that
   the computer store may have used on your computer, and then erased.
2) Backup everything that was preinstalled that you don't have disks
   for. (Including the free diagnostics stuff :o)
3) Repartition the drive (recommended partition sizes 250M)
   (Be sure to leave lots of room for a couple Linux partitions :o)
4) Reinstall your software.

I don't know about Partition Magic, but I know that other
repartitioning programs just re-size the partition, and leave the
cluster size alone.  If this is the case, your repartitioning will NOT
get you around the cluster wastage problem.


Mike A. Harris        |             http://blackwidow.saultc.on.ca/~mharris
Computer Consultant   |    My webpage has moved and my address has changed.
My dynamic address: http://blackwidow.saultc.on.ca/~mharris/ip-address.html
mailto:mharris AT blackwidow DOT saultc DOT on DOT ca

DOS must have's: 4DOS 5.50c  ftp://ftp.std.com/vendors/jpsoft

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