openstack team mailing list archive

[Scott Moser <smoser@xxxxxxxxxx>]

On Mon, 24 Sep 2012, Wangpan wrote:

> Thanks for your attention!
>
> - disk full  ----# I believe there is enough space, because I have tried to boot serveral instances after this error with the same image, they are all booted successfully.
> - permission issues    ----# Not this reason, too. explain as above.
>
> I still believe this is a race problem, if we convert to image from qcow2 to raw at a short interval, one of the convertion may fail,
> I have verified this by running two same commands continuously such as:
> qemu-img convert -f qcow2 -O raw  test.qcow2 test.part &
> and one of them give me the same error:
> qemu-img: error while writing sector 1052672: Input/output error

I would expect the above.  Or at least it surprises me very little.  I
doubt that qemu-img expects some other process to write to its output file
while it is.

Surely nothing in openstack is expecting to be able to have 2 instances of
'qemu-img convert' write to the same file concurrently, right?