On 01/15/2014 10:12 PM, ?????? wrote:
Hi Josh
# strings /usr/bin/qemu-system-x86_64 | grep rbd_aio
rbd_aio_write
rbd_aio_flush
rbd_aio_read
rbd_aio_create_completion
rbd_aio_release
rbd_aio_discard
rbd_aio_get_return_value
So, librbd's asynchronous flush is being used.
I set log settings, fetch the log and ping log with timestamped, all
logs are in the attachment.
Excellent, thanks.
It seems that I doesn't have permission to generate a new issue
on tracker.ceph.com, when I click the 'Register' it show a 'internal
error' page.
Seems to be working for me. In any case, I created
http://tracker.ceph.com/issues/7165 to track the problem.
Looking through the logs, it may have been already solved in
a couple commits after 0.67.5. Namely, the cache was starting the flush
of too much dirty data at once while holding a lock, preventing other
I/O from the guest from starting, and thus blocking the qemu thread
handling the I/O.
I added the relevant commits to the wip-objectcacher-flusher-dumpling
branch in ceph.git. Could you install librbd from that branch and see
if it fixes the problem? Instructions for getting these packages are:
http://ceph.com/docs/master/install/get-packages/#add-ceph-development
Thanks,
Josh