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

[Philipp Schmidt]

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

[Thomas Huth (th-huth)]

QEMU 0.12 is pretty much outdated ...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?

[Philipp Schmidt (philsbln)]

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 QEMU 0.12 is pretty much outdated ...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: [phone])---<---(jabber: <email address hidden>)----'

[Thomas Huth (th-huth)]

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.

[Launchpad Janitor (janitor)]

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

[Paolo Bonzini (bonzini)]

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.