On Tue, Feb 23, 2010 at 11:48:20AM +0100, Darko Petrovi? wrote:
> Hi all,
>
> When I try to use tap:aio configuration I get the following error message
> upon executing xm create:
> Error: Failed to create device.
> stdout: unrecognized child response
> stderr:
> Check that target "/dev/vg0/lvol0" exists and that blktap2 driver
> installed in dom0.
>
> This is what I find in /var/log/syslog:
> Feb 23 11:37:38 xen-1 tapdisk2[3523]: Created /dev/xen/blktap-2/blktap2
> device
> Feb 23 11:37:38 xen-1 tapdisk2[3523]: Created /dev/xen/blktap-2/tapdev2
> device
> Feb 23 11:37:38 xen-1 tapdisk2[3523]: new interface: ring: 252, device:
> 254, minor: 2
> Feb 23 11:37:38 xen-1 tapdisk2[3523]: I/O queue driver: lio
> Feb 23 11:37:38 xen-1 tapdisk2[3523]: Incorrect magic in shared info.
> Feb 23 11:37:38 xen-1 tapdisk2[3523]: Failed to open shared info.
> Feb 23 11:37:38 xen-1 kernel: [ 1002.545721] blktap_sysfs_create: adding
> attributes for dev ec6f00c0
> Feb 23 11:37:38 xen-1 kernel: [ 1002.545728] blktap_control_allocate_tap:
> allocated tap c1ef8800
> Feb 23 11:37:38 xen-1 kernel: [ 1002.547589] tapdisk2[3523]: segfault at
> 10 ip b758aa00 sp bfd07dd4 error 4 in [1]libpthread-2.7.so[b7583000+15000]
> Feb 23 11:37:38 xen-1 logger: /etc/xen/scripts/xen-hotplug-cleanup:
> XENBUS_PATH=backend/vkbd/4/0
> Feb 23 11:37:38 xen-1 logger: /etc/xen/scripts/xen-hotplug-cleanup:
> XENBUS_PATH=backend/vfb/4/0
>
> Here is also the corresponding part of my DomU configuration file:
> disk = ['tap:aio:/dev/vg0/lvol0,xvda,w','tap:aio:/dev/vg0/swap,xvdb,w']
>
> The pv_ops dom0 kernel is compiled with CONFIG_XEN_BLKDEV_TAP=y. Both
> lvol0 and swap do exist, I've double-checked it (namely, they work with
> phy: instead of tap:aio).
> What could be wrong?
>
What's your pv_ops dom0 version? when did you check it out?
Only the very recent (as of a couple of days ago) pv_ops dom0
kernels have working blktap2.
-- Pasi
