If your glance configuration includes the following, RBD images will be cached to disk on the API server: [paste_deploy] flavor = keystone+cachemanagement See [1] for the configuration steps for Glance. [1] http://docs.ceph.com/docs/master/rbd/rbd-openstack/#configuring-glance -- Jason Dillaman ----- Original Message ----- > From: "Vickey Singh" <vickey.singh22693@xxxxxxxxx> > To: "Jason Dillaman" <dillaman@xxxxxxxxxx> > Cc: ceph-users@xxxxxxxxxxxxxx, "ceph-users" <ceph-users@xxxxxxxx> > Sent: Tuesday, February 9, 2016 11:11:31 AM > Subject: Re: Tips for faster openstack instance boot > Guys Thanks a lot for your response. > We are running OpenStack Juno + Ceph 94.5 > @ Jason Dillaman Can you please explain what do you mean by "Glance is > configured to cache your RBD image" ? This might give me some clue. > Many Thanks. > On Mon, Feb 8, 2016 at 10:33 PM, Jason Dillaman < dillaman@xxxxxxxxxx > > wrote: > > If Nova and Glance are properly configured, it should only require a quick > > clone of the Glance image to create your Nova ephemeral image. Have you > > double-checked your configuration against the documentation [1]? What > > version of OpenStack are you using? > > > To answer your questions: > > > > - From Ceph point of view. does COW works cross pool i.e. image from > > > glance > > > > pool ---> (cow) --> instance disk on nova pool > > > Yes, cloning copy-on-write images works across pools > > > > - Will a single pool for glance and nova instead of separate pool . will > > > help > > > > here ? > > > Should be no change -- the creation of the clone is extremely lightweight > > (add the image to a directory, create a couple metadata objects) > > > > - Is there any tunable parameter from Ceph or OpenStack side that should > > > be > > > > set ? > > > I'd double-check your OpenStack configuration. Perhaps Glance isn't > > configured with "show_image_direct_url = True", or Glance is configured to > > cache your RBD images, or you have an older OpenStack release that requires > > patches to fully support Nova+RBD. > > > [1] http://docs.ceph.com/docs/master/rbd/rbd-openstack/ > > > -- > > > Jason Dillaman > > > ----- Original Message ----- > > > > From: "Vickey Singh" < vickey.singh22693@xxxxxxxxx > > > > > To: ceph-users@xxxxxxxxxxxxxx , "ceph-users" < ceph-users@xxxxxxxx > > > > > Sent: Monday, February 8, 2016 9:10:59 AM > > > > Subject: Tips for faster openstack instance boot > > > > Hello Community > > > > I need some guidance how can i reduce openstack instance boot time using > > > Ceph > > > > We are using Ceph Storage with openstack ( cinder, glance and nova ). All > > > > OpenStack images and instances are being stored on Ceph in different > > > pools > > > > glance and nova pool respectively. > > > > I assume that Ceph by default uses COW rbd , so for example if an > > > instance > > > is > > > > launched using glance image (which is stored on Ceph) , Ceph should take > > > COW > > > > snapshot of glance image and map it as RBD disk for instance. And this > > > whole > > > > process should be very quick. > > > > In our case , the instance launch is taking 90 seconds. Is this normal ? > > > ( > > > i > > > > know this really depends one's infra , but still ) > > > > Is there any way , i can utilize Ceph's power and can launch instances > > > ever > > > > faster. > > > > - From Ceph point of view. does COW works cross pool i.e. image from > > > glance > > > > pool ---> (cow) --> instance disk on nova pool > > > > - Will a single pool for glance and nova instead of separate pool . will > > > help > > > > here ? > > > > - Is there any tunable parameter from Ceph or OpenStack side that should > > > be > > > > set ? > > > > Regards > > > > Vickey > > > > _______________________________________________ > > > > ceph-users mailing list > > > > ceph-users@xxxxxxxxxxxxxx > > > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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