[Qemu-devel] qemu-img needs "-O host_device" describing

[Adrian Bridgett]

I've been trying to convert some personal KVM qemu (raw) file images
to raw LVs using kvm-img -O raw.  There's a short version and long
version of this tale.

The short version is "here is a patch to add '-O host_device' to the
manpage", perhaps we should also warn if "kvm-img convert -O raw" is
used on a block device (or even just automatically use host_device?)

The long version is that first of all I changed block/raw-posix.c so
that it didn't try and ftruncat() block devices and then eventually
tracked down why "kvm-img convert -O raw" fails to block devices (it
seeks past holes effectively which is good on files, but not block
devices).

Digging a bit deeper I found reference to "host_device" type and it
turns out that using that as an output format fixes both these issues
- with only one buglet - a hopefully irrelevant error:

  kvm-img convert -O host_device /var/lib/vm/bishop-disk 
/dev/rootvg/bishop-disk 
  Unknown option 'size'

This on qemu-kvm 0.11.

Thanks,

Adrian
-- 
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qemu-truncate.diff
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qemu-host_device.diff
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