Hi Jason,
Thank you very much for your reply.
I think the RBD trash is a good way. But, the QoS in Ceph is a better solution.
I am looking forward to the backend QoS of Ceph.
Thanks.
At 2018-06-06 21:53:23, "Jason Dillaman" <jdillama@xxxxxxxxxx> wrote: >The 'rbd_concurrent_management_ops' setting controls how many >concurrent, in-flight RADOS object delete operations are possible per >image removal. The default is only 10, so given ten 10 images being >deleted concurrently, I am actually surprised that blocked all IO from >your VMs. > >Adding support for limiting the maximum number of concurrent image >deletions would definitely be an OpenStack enhancement. There is an >open blueprint for optionally utilizing the RBD trash instead of >having Cinder delete the images [1], which would allow you to defer >deletions to whenever is convenient. Additionally, once Ceph adds >support for backend QoS (fingers crossed in Nautilus), we can change >librbd to flag all IO for maintenance activities to background (best >effort) priority, which might be the best long-term solution. > >[1] https://blueprints.launchpad.net/cinder/+spec/rbd-deferred-volume-deletion > >On Wed, Jun 6, 2018 at 6:40 AM, Yao Guotao <yaoguo_tao@xxxxxxx> wrote: >> Hi Cephers, >> >> We use Ceph with Openstack by librbd library. >> >> Last week, my colleague delete 10 volumes from Openstack dashboard at the >> same time, each volume has about 1T used. >> During this time, the disk of OSDs are busy, and there have no I/O for >> normal vm. >> >> So, I want to konw if there are any parameters that can be set to throttle? >> >> I find a parameter about rbd op is 'rbd_concurrent_management_ops'. >> I am trying to figure out how it works in code, and I find the parameter can >> only control the asyncchronous deletion of all objects of an image. >> >> Besides, Should it be controlled at Openstack Nova or Cinder layer? >> >> Thanks, >> Yao Guotao >> >> >> >> >> >> _______________________________________________ >> ceph-users mailing list >> ceph-users@xxxxxxxxxxxxxx >> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >> > > > >-- >Jason
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