On Fri, Jan 13, 2017 at 5:11 AM, Vincent Godin <vince.mlist@xxxxxxxxx> wrote: > We are using a production cluster which started in Firefly, then moved to > Giant, Hammer and finally Jewel. So our images have different features > correspondind to the value of "rbd_default_features" of the version when > they were created. > We have actually three pack of features activated : > image with : > - layering ~ 1 > - layering, striping ~3 > - layering, exclusive-lock, object-map, fast-diff, deep-flatten ~ 61 > > 1) Is it a good idea to try to give all images the same features ? It isn't needed. > 2) Is it possible to disable the striping feature on an already created > image (we never specify any stripe-unit nor stripe-count) ? Negative -- striping cannot be dynamically disabled because it would result in potentially altering the structure and placement of the data within the image. If your stripe-unit is the object size and the stripe count is 1, that's a special case where the flag is essentially ignored. > 3) What is the behaviour of an already created image on which we activate > the object-map feature ? Will a process try to rebuild a index of used > blocks - if no, if we delete later the image, will ceph try to remove all > the blocks or only the blocks refered by object-map index ? You would need to run "rbd object-map rebuild <image-spec>" to rebuild the object map. Until it is rebuilt, it will be considered invalid and won't be used for reference. You can determine the object map state by running "rbd info <image-spec>" > 4) We are on Jewel but with tunables set to hammer (Centos 7.2). What are > the best default features to set in that case ? (we use Ceph under an > Openstack for glance, nova and cinder We feel like the current defaults are a good mix of features for everyday use of non-shared images or non-krbd images. Most importantly, all the default features can be dynamically disabled if your needs for the image change. > > > > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > -- Jason _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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