device: 0.867
vnc: 0.837
PID: 0.730
other: 0.705
KVM: 0.675
graphic: 0.673
boot: 0.635
performance: 0.602
debug: 0.585
permissions: 0.573
socket: 0.553
files: 0.535
semantic: 0.527
network: 0.477

qemu does not pass sector size from physical devices to virtual devices

When passing a physical disk (i.e. a multipathed fcal volume in my case) with a 4k sector size as raw image to qemu (-drive file=/dev/mapper/hartebeest-sys,if=none,id=drive-virtio-disk0,boot=on,format=raw), the resulting virtual device has a sector size of 512b, rendering the partition table unusable!

QEMU 0.12 is pretty much outdated ... can you still reproduce this issue with the latest version of QEMU, or can we close this bug nowadays?

Hi,

I can’t verify it for the logical block size right away, but 
this bug still present for the physical block size in qemu-kvm 1:2.1+dfsg-1.

I will try to verify this bug with testing soon

> On 20. Mar 2017, at 23:57, Thomas Huth <email address hidden> wrote:
> 
> QEMU 0.12 is pretty much outdated ... can you still reproduce this issue
> with the latest version of QEMU, or can we close this bug nowadays?
> 
> ** Changed in: qemu
>       Status: New => Incomplete
> 
> -- 
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/877498
> 
> Title:
>  qemu does not pass sector size from physical devices to virtual
>  devices
> 
> Status in QEMU:
>  Incomplete
> 
> Bug description:
>  When passing a physical disk (i.e. a multipathed fcal volume in my
>  case) with a 4k sector size as raw image to qemu (-drive
>  file=/dev/mapper/hartebeest-sys,if=none,id=drive-virtio-
>  disk0,boot=on,format=raw), the resulting virtual device has a sector
>  size of 512b, rendering the partition table unusable.
> 
>  Versions used: QEMU 0.12.5 (qemu-kvm-0.12.5) from debian unstable
> 
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/qemu/+bug/877498/+subscriptions
> 

AVE!
  Philipp S. Tiesel / phils…
-- 
   {phils}--->---(<email address hidden>)--->---(http://phils.in-panik.de)----,
      wenn w eine   aube ist dn      man au dran dre en                   |
           o     Schr        an muss     hc         h   (Kurt Schwitters) |
:wq!  <----(phone: +49-179-6737439)---<---(jabber: <email address hidden>)----'



QEMU 2.1 is also not supported anymore. Please test with the latest upstream QEMU version (2.8 ... or the latest 2.9 release candidate) - or otherwise report the bug in the bug tracker of your distribution instead.

[Expired for QEMU because there has been no activity for 60 days.]

Recent QEMU is able to do read-modify-write operations when using 512 byte logical sectors in the VM and 4K logical sectors in the host.