qemu-img bug with dynamic vhd

[z22lad]

Hye, i found a problem with qemu-img when trying to get info of a dynamic vhd. I made imgae of my 60GB computer hard drive with disk2vhd. The dynamic vhd is 21gb size.

With 1.0-rc3 version :
running command: qemu-img info 60_GB.VHD
qemu-img: Could not open '60_GB.VHD' : File too large

0.14.1 version give me wrong information :
image: 60_GB.VHD
file format: vpc
virtual size: 127G (136899993600 bytes)
disk size: 21G

Thanks for reply.

[Stefan Hajnoczi (stefanha)]

On Wed, Nov 23, 2011 at 11:33 AM, z22lad <email address hidden> wrote:
> Hye, i found a problem with qemu-img when trying to get info of a
> dynamic vhd. I made imgae of my 60GB computer hard drive with disk2vhd.
> The dynamic vhd is 21gb size.
>
> With 1.0-rc3 version :
> running command: qemu-img info 60_GB.VHD
> qemu-img:  Could not open '60_GB.VHD' : File too large
>
> 0.14.1 version give me wrong information :
> image: 60_GB.VHD
> file format: vpc
> virtual size: 127G (136899993600 bytes)
> disk size: 21G

Which host OS are you running qemu-img on? Is it 32- or 64-bit?

I wonder if you get the same behavior when using qemu-img convert
instead of "disk2vhd" to create a vhd file.

Stefan

[franxico (batuque)]

Hi,

I'm having the same problem. I'm using qemu-img 1.0, running from a Ubuntu Server 12.04 x64 on a SW RAID, ext4.

The .VHD has 29GB and was made using disk2vhd.

Here is the command and the results:
sudo kvm-img convert -f vpc -O raw image.VHD image.img
[sudo] password for sysop:
kvm-img: Could not open 'image.VHD': File too large
kvm-img: Could not open 'image.VHD'

Same error doing a simple qemu-img info image.vhd

Thanks for your help

[Stefan Hajnoczi (stefanha)]

On Mon, Sep 3, 2012 at 10:41 AM, franxico <email address hidden> wrote:
> Hi,
>
> I'm having the same problem. I'm using qemu-img 1.0, running from a
> Ubuntu Server 12.04 x64 on a SW RAID, ext4.
>
> The .VHD has 29GB and was made using disk2vhd.
>
> Here is the command and the results:
> sudo kvm-img convert -f vpc -O raw image.VHD image.img
> [sudo] password for sysop:
> kvm-img: Could not open 'image.VHD': File too large
> kvm-img: Could not open 'image.VHD'
>
> Same error doing a simple qemu-img info image.vhd

Serge Hallyn introduced the size check when VHD files are opened, you
can read about the background here:
http://patchwork.ozlabs.org/patch/106736/

I'm not sure if QEMU has a bug or lacks support for the file format
version used by disk2vhd.

>
> Thanks for your help
>
> --
> You received this bug notification because you are a member of qemu-
> devel-ml, which is subscribed to QEMU.
> https://bugs.launchpad.net/bugs/893956
>
> Title:
> qemu-img bug with dynamic vhd
>
> Status in QEMU:
> New
>
> Bug description:
> Hye, i found a problem with qemu-img when trying to get info of a
> dynamic vhd. I made imgae of my 60GB computer hard drive with
> disk2vhd. The dynamic vhd is 21gb size.
>
> With 1.0-rc3 version :
> running command: qemu-img info 60_GB.VHD
> qemu-img: Could not open '60_GB.VHD' : File too large
>
> 0.14.1 version give me wrong information :
> image: 60_GB.VHD
> file format: vpc
> virtual size: 127G (136899993600 bytes)
> disk size: 21G
>
> Thanks for reply.
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/qemu/+bug/893956/+subscriptions
>

[Serge Hallyn (serge-hallyn)]

Though that commit and the comments were about 127G images. HIs is only 27G.

Also, 'qemu-img info' is also showing the error, which shows that this is not being done on vpc_create().

So I think this is a case of qemu-img actually failing to properly parse the FHD file.

[Stefan Hajnoczi (stefanha)]

On Tue, Sep 4, 2012 at 4:00 PM, Serge Hallyn <email address hidden> wrote:
> Though that commit and the comments were about 127G images. HIs is only
> 27G.

The 127 GB limit applies to the virtual disk size, not to the size of
the image file itself.

> Also, 'qemu-img info' is also showing the error, which shows that this
> is not being done on vpc_create().

I'm not sure what you mean. Your commit (efc8243d00) added an -EFBIG
return to vcp_open(), not vpc_create(). This will affect qemu-img
info.

We need the header/footer contents to be sure what's going on here.

Stefan

[Stefan Hajnoczi (stefanha)]

On Mon, Sep 3, 2012 at 10:41 AM, franxico <email address hidden> wrote:
> Hi,
>
> I'm having the same problem. I'm using qemu-img 1.0, running from a
> Ubuntu Server 12.04 x64 on a SW RAID, ext4.
>
> The .VHD has 29GB and was made using disk2vhd.
>
> Here is the command and the results:
> sudo kvm-img convert -f vpc -O raw image.VHD image.img
> [sudo] password for sysop:
> kvm-img: Could not open 'image.VHD': File too large
> kvm-img: Could not open 'image.VHD'
>
> Same error doing a simple qemu-img info image.vhd

Please post the output of the following commands:

$ hexdump -C -n 512 image.VHD
$ hexdump -C -n 512 -s $(($(ls -l image.VHD | awk '{ print $5 }') -
512)) image.VHD

This will show the file header/footer, which contains fields that are
validated when opening the file.

Thanks,
Stefan

[Serge Hallyn (serge-hallyn)]

Quoting Stefan Hajnoczi (<email address hidden>):
> On Tue, Sep 4, 2012 at 4:00 PM, Serge Hallyn <email address hidden> wrote:
> > Though that commit and the comments were about 127G images. HIs is only
> > 27G.
>
> The 127 GB limit applies to the virtual disk size, not to the size of
> the image file itself.

I thought he had converted a roughly 26GB physical disk, assumed (perhaps
wrongly) that was the virtual disk size.

> > Also, 'qemu-img info' is also showing the error, which shows that this
> > is not being done on vpc_create().
>
> I'm not sure what you mean. Your commit (efc8243d00) added an -EFBIG
> return to vcp_open(), not vpc_create(). This will affect qemu-img
> info.

Oops, good point. Thanks.

> We need the header/footer contents to be sure what's going on here.

[Bobby Dimmette (bjdimmette)]

qemu-img fails to read a disk2vhd (VHD) image created from a Windows Server 2003.
qemu-img will read and convert a VDI image created from that VHD

VHD header/footer details:

[root@T3400 ]# qemu-img info vhd/p.vhd
qemu-img: Could not open 'vhd/p.vhd': File too large

[root@T3400 ]# ./vhddump -vv -s vhd/p.vhd
Positioning descriptor to VHD footer...
Reading VHD footer...
------------------------
 VHD Footer (512 bytes)
------------------------
 Cookie = conectix
 Features = 0x00000002
 File Format Version = 0x00010000
 Data Offset = 0x0000000000000200
 Time Stamp = 0x1893342A
 Creator Application = 0x64327600
 Creator Version = 0x00010000
 Creator Host OS = 0x5769326B
 Original Size = 0x000000222E6F4000
                     = 140006 MB + 976 KiB
 Current Size = 0x000000222E6F4000
                     = 140006 MB + 976 KiB
 Disk Geometry = 0xFFFF10FF
           Cylinders = 65535
               Heads = 16
       Sectors/Track = 255
 Disk Type = 0x00000003
                     = Dynamic hard disk
 Checksum = 0xFFFFEDD8
 Unique ID = 765e24b9-1e33-594a-864e-f39aea210f24
 Saved State = 0x00
 Reserved = <...427 bytes...>
===============================================
Detecting disk type...
Dynamic hard disk detected.
Positioning descriptor to read VHD footer copy...
Reading VHD footer copy...
------------------------
 VHD Footer (512 bytes)
------------------------
 Cookie = conectix
 Features = 0x00000002
 File Format Version = 0x00010000
 Data Offset = 0x0000000000000200
 Time Stamp = 0x1893342A
 Creator Application = 0x64327600
 Creator Version = 0x00010000
 Creator Host OS = 0x5769326B
 Original Size = 0x000000222E6F4000
                     = 140006 MB + 976 KiB
 Current Size = 0x000000222E6F4000
                     = 140006 MB + 976 KiB
 Disk Geometry = 0xFFFF10FF
           Cylinders = 65535
               Heads = 16
       Sectors/Track = 255
 Disk Type = 0x00000003
                     = Dynamic hard disk
 Checksum = 0xFFFFEDD8
 Unique ID = 765e24b9-1e33-594a-864e-f39aea210f24
 Saved State = 0x00
 Reserved = <...427 bytes...>
===============================================
Reading VHD dynamic disk header...
--------------------------------------
 VHD Dynamic Disk Header (1024 bytes)
--------------------------------------
 Cookie = cxsparse
 Data Offset = 0xFFFFFFFFFFFFFFFF
 Table Offset = 0x0000000000000600
 Header Version = 0x00010000
 Max Table Entries = 0x00011174
 Block Size = 0x00200000
 Checksum = 0xFFFFF3F1
 Parent UUID = 00000000-0000-0000-0000-000000000000
 Parent TS = 0x00000000
                       0 (10)
 Reserved = <...4 bytes...>
 Parent Unicode Name = <...512 bytes...>
 Parent Loc Entry 1 = <...24 bytes...>
 Parent Loc Entry 2 = <...24 bytes...>
 Parent Loc Entry 3 = <...24 bytes...>
 Parent Loc Entry 4 = <...24 bytes...>
 Parent Loc Entry 5 = <...24 bytes...>
 Parent Loc Entry 6 = <...24 bytes.....

[Thomas Huth (th-huth)]

Can you still reproduce this problem with the latest version of QEMU (currently version 2.9.0)?

[Bobby Dimmette (bjdimmette)]

No, sorry. The environment was retired in 2014 and we took a different direction.

-Bobby

-----Original Message-----
From: <email address hidden> [mailto:<email address hidden>] On Behalf Of Thomas Huth
Sent: Wednesday, June 07, 2017 4:44 AM
To: <email address hidden>
Subject: [Bug 893956] Re: qemu-img bug with dynamic vhd

Can you still reproduce this problem with the latest version of QEMU (currently version 2.9.0)?

** Changed in: qemu
       Status: New => Incomplete

--
You received this bug notification because you are subscribed to the bug report.
https://bugs.launchpad.net/bugs/893956

Title:
  qemu-img bug with dynamic vhd

Status in QEMU:
  Incomplete

Bug description:
  Hye, i found a problem with qemu-img when trying to get info of a
  dynamic vhd. I made imgae of my 60GB computer hard drive with
  disk2vhd. The dynamic vhd is 21gb size.

  With 1.0-rc3 version :
  running command: qemu-img info 60_GB.VHD
  qemu-img: Could not open '60_GB.VHD' : File too large

  0.14.1 version give me wrong information :
  image: 60_GB.VHD
  file format: vpc
  virtual size: 127G (136899993600 bytes)
  disk size: 21G

  Thanks for reply.

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/893956/+subscriptions