The question is how to change physical size of hard disk by software?

I am moving winxp to virtual .vdi disk. Correct way is to take image of the whole harddisk dd if=/dev/sda etc. Problem is that the disks are huge and I only need the first 10GB which is C: drive.

So how can I edit the disk information ( partition table? MBR? ) on the physical source hard drive so so that it looks like 10GB hard drive instead of 250GB? After editing the size information I will start windows which will most probably do chkdsk etc. After windows and whole system ( grub etc. ) thinks that the disk is 10GB I can take image of that 10GB and convert it to 10GB virtual .vdi disk.

I have tried take copy of first 10GB of the disk just ignoring the rest. I did something like
dd if=/dev/sda of=./cdrive.dd bs=1M count=10K
and then tested
mount -o loop,offset=32256 -t ntfs ./cdrive.dd ./cdisk
and I could read the files normally, so this partially works.

I have not managed to convert this cut image to a working virtual .vdi disk yet. I have been using VBoxmanage converfromraw tool which did not give errors but did not manage boot the .vdi yet.

You can use the dd command to copy a single partition on the drive rather than the full drive itself. E.g. dd if=/dev/sda1 of=/*somepath*/partition1.img

Wikipedia has some helpful examples: http://en.wikipedia.org/wiki/Dd_%28Unix%29

1 members found this post helpful.

Whole disk need to be copied when making image for virtualbox.

"If making an image, DO NOT image just the partition, this will not work! "
http://www.virtualbox.org/wiki/Migrate_Windows

Now I am looking for tools to create MBR manually and then copying only one partition to a image file.