Btw, in terms of fio for example - how can I practically see the benefit of striping?
2016-01-29 22:45 GMT+08:00 Jason Dillaman <dilla...@redhat.com>: > That was intended as an example of how to use fancy striping with RBD images. > The stripe unit and count are knobs to tweak depending on your IO situation. > > Taking a step back, what are you actually trying to accomplish? The flatten > operation doesn't necessarily fit the use case for this feature. Instead, it > is useful for applications that issue many small, sequential IO operations. > If you set your stripe unit to be the IO size (and properly align it), the IO > load will be able to be distributed to more OSDs in parallel. > > -- > > Jason Dillaman > > > ----- Original Message ----- > >> From: "Bill WONG" <wongahsh...@gmail.com> >> To: "Jason Dillaman" <dilla...@redhat.com> >> Cc: "ceph-users" <ceph-users@lists.ceph.com> >> Sent: Friday, January 29, 2016 12:30:24 AM >> Subject: Re: [ceph-users] Striping feature gone after flatten with cloned >> images > >> Hi Jason, > >> it works fine.... but flatten take how longer than than before.. >> i would like to know how to decide the --stripe-unit & --stripe-count to gain >> the best performance? >> i see you put unit of 4K and count with 16.. why? >> -- >> --stripe-unit 4K --stripe-count 16 >> -- > >> thank you! > >> On Fri, Jan 29, 2016 at 11:15 AM, Jason Dillaman < dilla...@redhat.com > >> wrote: > >> > When you set "--stripe-count" to 1 and set the "--stripe-unit" to the >> > object >> > size, you have actually explicitly told the rbd CLI to not use "fancy" >> > striping. A better example would be something like: >> > >> > rbd clone --stripe-unit 4K --stripe-count 16 storage1/cloudlet-1@snap1 >> > storage1/cloudlet-1-clone >> > >> > -- >> > >> > Jason Dillaman >> > >> > ----- Original Message ----- >> > >> > > From: "Bill WONG" < wongahsh...@gmail.com > >> >> > > To: "Jason Dillaman" < dilla...@redhat.com > >> >> > > Cc: "ceph-users" < ceph-users@lists.ceph.com > >> >> > > Sent: Thursday, January 28, 2016 10:08:38 PM >> >> > > Subject: Re: [ceph-users] Striping feature gone after flatten with cloned >> >> > > images >> > >> > > hi jason, >> > >> > > how i can make the stripping parameters st the time of clone creation? as >> > > i >> >> > > have tested, which looks doesn't work properly.. >> >> > > the clone image still without stripping.. any idea? >> >> > > -- >> >> > > rbd clone --stripe-unit 4096K --stripe-count 1 storage1/cloudlet-1@snap1 >> >> > > storage1/cloudlet-1-clone >> >> > > rbd flatten storage1/cloudlet-1-clone >> >> > > rbd info storage1/cloudlet-1-clone >> >> > > rbd image 'cloudlet-1-clone': >> >> > > size 1000 GB in 256000 objects >> >> > > order 22 (4096 kB objects) >> >> > > block_name_prefix: rbd_data.5ecd364dfe1f8 >> >> > > format: 2 >> >> > > features: layering >> >> > > flags: >> >> > > --- >> > >> > > On Fri, Jan 29, 2016 at 3:54 AM, Jason Dillaman < dilla...@redhat.com > >> >> > > wrote: >> > >> > > > You must specify the clone's striping parameters at the time of its >> >> > > > creation >> >> > > > -- it is not inherited from the parent image. >> >> > > >> > >> > > > -- >> >> > > >> > >> > > > Jason Dillaman >> >> > > >> > >> > > > ----- Original Message ----- >> >> > > >> > >> > > > > From: "Bill WONG" < wongahsh...@gmail.com > >> >> > > >> >> > > > > To: "ceph-users" < ceph-users@lists.ceph.com > >> >> > > >> >> > > > > Sent: Thursday, January 28, 2016 1:25:12 PM >> >> > > >> >> > > > > Subject: [ceph-users] Striping feature gone after flatten with cloned >> >> > > > > images >> >> > > >> > >> > > > > Hi, >> >> > > >> > >> > > > > i have tested with the flatten: >> >> > > >> >> > > > > 1) make a snapshot of image >> >> > > >> >> > > > > 2) protect the snapshot >> >> > > >> >> > > > > 3) clone the snapshot >> >> > > >> >> > > > > 4) flatten the clone >> >> > > >> >> > > > > then i found issue: >> >> > > >> >> > > > > with the original image / snapshot or the clone before flatten, all >> > > > > are >> >> > > > > with >> >> > > >> >> > > > > stripping feature, BUT after flattened the clone, then there is no >> > > > > more >> >> > > >> >> > > > > Stripping with the clone image...what is the issue? and how can >> > > > > enable >> >> > > > > the >> >> > > >> >> > > > > striping feature? >> >> > > >> > >> > > > > thank you! >> >> > > >> > >> > > > > _______________________________________________ >> >> > > >> >> > > > > ceph-users mailing list >> >> > > >> >> > > > > ceph-users@lists.ceph.com >> >> > > >> >> > > > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >> >> > > >> > _______________________________________________ > ceph-users mailing list > ceph-users@lists.ceph.com > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
