Re: [Qemu-devel] [PATCH v3 0/6]: block: Add I/O status support

[Luiz Capitulino <lcapitulino@redhat.com>]

On Wed, 28 Sep 2011 17:45:27 +0800
hkran <hkran@vnet.linux.ibm.com> wrote:

> On 09/27/2011 04:43 AM, Luiz Capitulino wrote:
> > This series adds support to the block layer to keep track of devices'
> > I/O status. That information is also made available in QMP and HMP.
> >
> > The goal here is to allow management applications that miss the
> > BLOCK_IO_ERROR event to able to query the VM to determine if any device has
> > caused the VM to stop and which device caused it.
> >
> > Here's an HMP example:
> >
> >    (qemu) info status
> >    VM status: paused (io-error)
> >    (qemu) info block
> >    ide0-hd0: removable=0 io-status=ok file=disks/test2.img ro=0 drv=qcow2 encrypted=0
> >    ide0-hd1: removable=0 io-status=nospace file=/dev/vg_doriath/kvmtest ro=0 drv=qcow2 encrypted=0
> >    ide1-cd0: removable=1 locked=0 io-status=ok [not inserted]
> >    floppy0: removable=1 locked=0 [not inserted]
> >    sd0: removable=1 locked=0 [not inserted]
> >
> > The session above shows that the VM is stopped due to an I/O error. By using
> > the info block command it's possible to determine that the 'ide0-hd1' device
> > caused the error, which turns out to be due to no space.
> >
> > changelog
> > ---------
> >
> > v3
> >
> > o Introduce bdrv_iostatus_disable()
> > o Also reset the I/O status on bdrv_attach_dev()
> > o Fix bad assert() in bdrv_iostatus_enable()
> > o Improve documentation
> >
> > v2
> >
> > o Rebase against latest master
> > o Renamed bdrv_iostatus_update() to bdrv_iostatus_set_err()
> > o Minor changelog clarifications
> >
> >   block.c         |   57 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >   block.h         |   10 +++++++++
> >   block_int.h     |    1 +
> >   hw/ide/core.c   |    2 +
> >   hw/scsi-disk.c  |    2 +
> >   hw/virtio-blk.c |    2 +
> >   monitor.c       |    6 +++++
> >   qmp-commands.hx |    6 +++++
> >   8 files changed, 86 insertions(+), 0 deletions(-)
> >
> Hi,
> 
> How to reproduce a scenario in which the VM is stopped due to the I/O error?
> I tried several times by copying data from one place to another place in 
> guest OS and finally the system prompted me that there is no space is 
> available, however it did not
> cause any I/O error and not stop the VM either.

I use the test-case described here:

 http://lists.gnu.org/archive/html/qemu-devel/2011-08/msg03800.html