Re: muLinux base floppy image and DOS tools

From: Jef Knoors (
Date: Mon May 01 2000 - 09:20:08 CEST

----- Original Message -----
From: Miguel Angel <>
To: Mulinux <>
Sent: Friday, April 28, 2000 4:41 PM
Subject: Re: muLinux base floppy image and DOS tools

> El Fri, 28 Apr 2000, "Jef Knoors" <> kindly wrote:
> > I would like to make a raw image of my harddisk (the first 300Mb) is
> > possible with
> > "dd if=/dev/hda1 bs=1024k count=300000 of=/tmp/myfile"
> > or am I mistaken ? (I don't dear to try and lose all information)
> > Jef
> Really no problem at all. I used a sort of this to make backups of entire
> partitions many times and neved had a problem:
> dd if=/dev/hda1 bs=4096 |gzip >/tmp/myfile.gz
> Note that bs=4096, that is better targeted at maximun hard disk
> speed. You do not need to use "count" since once reached the partition's
end it
> will stop the dump anyway.

My partition is 1200 Mb, I only want to back up the first 300 Mb that is
used. (backup the free space would enlarge the backup file ? or not?) I did
run defrag on the partition.
See , the problem is that I work in an office where I do all the computer
stuff, but my boss is not able to look any further than an desktop icon.
That means we have to use windows95 no mather how often it will crash.
Reinstalling means : losing a productive day of work
Thats why I need the 'rescue file'

>I also piped it to gzip to get a compressed image
> (less space, less time).
> Hint! You can increase the compresion ratio a lot cleaning the free space
> writing a dumb file.
> Suppose /dev/hda1 is mounted under /mnt
> If it is a FAT partition:
> dd if=/dev/zero of=/mnt/dumbfile
> rm /mnt/dumbfile
> umount /mnt
> will work fine

Sorry, I don't understand what will happen, you create an empty file and
than erase it again ?

> If it is ext2, since sectors full of 0 are not written to disk, you must
> any other fixed pattern (yes, for example)
> yes|dd of=/mnt/dumbfile
> ...
> Hope this help
> --
> Don't see the world trought a window, be open{source}minded, and be free
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