From: Miguel Angel (maacruz@navegalia.com)
Date: Fri Apr 28 2000 - 16:41:19 CEST
El Fri, 28 Apr 2000, "Jef Knoors" <jknoors@zonnet.nl> kindly wrote:
> I would like to make a raw image of my harddisk (the first 300Mb) is that
> 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 transference
speed. You do not need to use "count" since once reached the partition's end it
will stop the dump anyway. 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
If it is ext2, since sectors full of 0 are not written to disk, you must use
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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