Comments on: How-to grow any Qemu system image

By: Le Repaire du Sanglier des Ardennes » Blog Archive » [Kvm] Convertir une image virtuelle.

Sun, 06 Sep 2009 19:57:13 +0000

[...] http://kevin.deldycke.com/2007/04/how-to-grow-any-qemu-system-image/ Cet article a été publié le Jeudi 3 septembre 2009 à 22 h 46 min et est classé dans Kvm, [...]

By: tartanandsnarly

tartanandsnarly — Mon, 03 Nov 2008 20:49:57 +0000

Hi,
Just to say that I accomplished this on windows by replacing the dd and cat steps – with the windows type command…..

I created the raw image:

CMD> qemu-img convert disk.qcow -O raw rawdisk1.raw

then created a copy of that:

CMD> copy rawdisk1.raw rawdisk2.raw

then used that to create a 3rd disk:

CMD> type rawdisk1.raw rawdisk2.raw > rawdisk3.raw

rawdisk3 could then boot normally both using qemu (in which case it was in the same condition as rawdisk1) and using the gparted iso – in which case the extra space could be seen.

I manipulated the partitions using gparted and grew the disk.

…as they say in Scotland – nae bother!

By: mjs

mjs — Thu, 22 May 2008 01:55:50 +0000

Install a qemu guest with linux and do it

Serious (or not) do not know!

Great tutorial btw, thanks

By: Porch

Porch — Wed, 16 Apr 2008 17:32:38 +0000

hello!
Great tutorial, but how i do it in windows?

By: phil

phil — Fri, 04 Apr 2008 02:36:12 +0000

I tried

cat zeros.raw >> system.raw

and it works!

At least for me, it’s an old linux ext2 image.

I also tried a gparted twist without the liveCD:

losetup /dev/loop1 system.raw
gparted /dev/loop1

it can see it, but cannot resize it

e2label: Bad magic number in superblock ...

By: Stubbs

Stubbs — Thu, 21 Feb 2008 17:48:09 +0000

The reason that cat system.raw zeros.raw > big10G.raw works is because you’re cat’ing the contents of both files before redirecting them to big10G.raw

In THEORY you should be able to do cat zeros.raw >> system.raw

but don’t quote me on that or blame me if it screws up your image

By: Anonymous

Anonymous — Tue, 12 Feb 2008 19:56:51 +0000

cat system.raw zeros.raw > big10G.raw

shouldn’t that be:

cat system.raw zeros.raw >> big10G.raw

Maybe this is why people are having trouble with it?

By: Bruno Grieder

Bruno Grieder — Thu, 18 Oct 2007 15:38:26 +0000

For details on “A disk read error has occurred.” please check this post: http://qemu-forum.ipi.fi/viewtopic.php?p=12362

The complete procedure would now be

1- Convert to a raw image

qemu-img convert system.qcow -O raw system.raw

2- Increase the size of the raw image

dd if=/dev/zero of=system.raw seek=N obs=1GB count=0

where N is the number of GigaBytes

3- Fix the NTFS BPB
Edit the raw file: hexedit system.raw
Goto to offset 7E00: 7E00
Change 80 to FF at offset 7E1A and save: FF --> Ctrl-x --> y

4- Boot Windows and check that you see a bigger disk in the admin tools

qemu hda system.raw

5- Use (fantastic) gparted to resize your NTFS partition

qemu -hda system.raw -cdrom gparted-livecd-0.3.4-5.iso -boot d

6- Boot windows to check and perform a chkdsk

qemu hda system.raw

7- If you need to save space, convert back to qcow

qemu-img convert system.raw -O qcow growed-system.qcow

By: Luca Bigliardi

Luca Bigliardi — Wed, 29 Aug 2007 17:08:00 +0000

If you have the image in a raw file and the host filesystem is supporting files with holes a simpler, quicker and less space-wasting way to increase your virtual disk size is:

dd if=/dev/zero of=system.raw bs=1 count=1 seek=10G

In this way dd leaves a hole of 10G from the beginning of the file (leaving everything untouched) and then writes a 0.

By: kev

kev — Mon, 14 May 2007 17:19:04 +0000

I’ve never encounter your problem during my experiments, and I have no idea how to fix your problem. Sorry…

I didn’t know the qemu-img info command. I don’t know if this can help you, but the only raw image file I still have return me this:

[kevin@localhost qemu]$ qemu-img info qemu-winXP.raw
image: qemu-winXP.raw
file format: raw
virtual size: 10G (10737418240 bytes)
disk size: 9.0G

As you can see, like you, I have the same 1G offset…