On Tue, Sep 8, 2015 at 6:54 PM, HEWLETT, Paul (Paul) <paul.hewlett@xxxxxxxxxxxxxxxxxx> wrote: > Hi All > > We have recently encountered a problem on Hammer (0.94.2) whereby we > cannot write objects > 2GB in size to the rados backend. > (NB not RadosGW, CephFS or RBD) > > I found the following issue > https://wiki.ceph.com/Planning/Blueprints/Firefly/Object_striping_in_librad > os which seems to address this but no progress reported. > > What are the implications of writing such large objects to RADOS? What > impact is expected on the XFS backend particularly regarding the size and > location of the journal? Huge RADOS objects are a bad idea. Think about the distribution of objects across PGs (i.e. sets of OSDs) and how different OSDs will be utilized - there is a bunch of reasons why OSDs reject objects larger than 90M by default. AFAIK libradosstriper was merged quite a while ago, before hammer I think, so it should be usable - people at CERN are building other things on top of it. Thanks, Ilya _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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