I have a partitioned virtual machine disk image created by vmware.

What I want to do is resize that by 10GB.

The file size is showing as 64424509440. Or 60GB.

So I ran this:

dd if=/dev/zero of=./win7.img seek=146800640 count=0

It ran without errors and I can verify the new size is in fact 75161927680 bytes or 70GB.

This is where it gets a little odd.

I started the guest domain in xen which is a Windows 7 enterprise machine.

What I was expecting to see in diskmgmt.msc is 2 partitions. 1 system partition at the start of around 100MB and near 60GB partition (which is C drive) followed by around 10GB of free space.

Actually what I saw was a 70GB partition!?!

That confused me... so I decided to run the Check Disk which when you set it on the C drive it asks you to reboot so it'll run on boot. So I did that and during the boot it ran the checks. It got all the way through stage 3 and didn't show any errors at all.

Looked at the partitions in disk manager and now C drive has shrunk back to 60GB and there is no free space.

What gives?

Ok, I thought I'd try mounting it under Dom0 and examining it with fdisk.

This is what I get when mounted

sudo xl block-attach 0 tap:aio:/home/xen/vms/otoy_v1202-xen.img xvda w
sudo fdisk -l /dev/xvda

Disk /dev/xvda: 64.4 GB, 64424509440 bytes
255 heads, 63 sectors/track, 7832 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x582dfc96

    Device Boot      Start         End      Blocks   Id  System
/dev/xvda1   *           1          13      102400    7  HPFS/NTFS
Partition 1 does not end on cylinder boundary.
/dev/xvda2              13        7833    62810112    7  HPFS/NTFS

Note the cylinder boundary comment.

When I run

sudo cfdisk /dev/xvda

I get:

FATAL ERROR: Bad primary partition 1: Partition ends in the final partial cylinder                       
                                                  Press any key to exit cfdisk

So I guess this is a bigger problem than first thought.

How can I fix this?

EDIT: Oops, the cylinder boundary thing is not a problem at all since disks have used LBA etc. So that threw me for a moment... still the problem exists...

Now this output looks a little different.

sudo sfdisk -uS -l /dev/xvda

Disk /dev/xvda: 7832 cylinders, 255 heads, 63 sectors/track
Units = sectors of 512 bytes, counting from 0

   Device Boot    Start       End   #sectors  Id  System
/dev/xvda1   *      2048    206847     204800   7  HPFS/NTFS
/dev/xvda2        206848 125827071  125620224   7  HPFS/NTFS
/dev/xvda3             0         -          0   0  Empty
/dev/xvda4             0         -          0   0  Empty

BTW: I do have a backup of the image so if you help me mess it up that's ok.

EDIT:

sudo parted /dev/xvda print free

Model: Xen Virtual Block Device (xvd)
Disk /dev/xvda: 64.4GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number  Start   End     Size    Type     File system  Flags
        32.3kB  1049kB  1016kB           Free Space
 1      1049kB  106MB   105MB   primary  ntfs         boot
 2      106MB   64.4GB  64.3GB  primary  ntfs
        64.4GB  64.4GB  1049kB           Free Space

Cool. Linux is showing free space is 10GB which is what I expect. The problem is windows isn't seeing this?