On Wed, Jan 9, 2013 at 8:00 AM, Noah Watkins <noah.watkins@xxxxxxxxxxx> wrote: > Hi Jutta, > > On Wed, Jan 9, 2013 at 7:11 AM, Lachfeld, Jutta > <jutta.lachfeld@xxxxxxxxxxxxxx> wrote: >> >> the current content of the web page http://ceph.com/docs/master/cephfs/hadoop shows a configuration parameter ceph.object.size. >> Is it the CEPH equivalent to the "HDFS block size" parameter which I have been looking for? > > Yes. By specifying ceph.object.size, the Hadoop will use a default > Ceph file layout with stripe unit = object size, and stripe count = 1. > This is effectively the same meaning as dfs.block.size for HDFS. > >> Does the parameter ceph.object.size apply to version 0.56.1? > > The Ceph/Hadoop file system plugin is being developed here: > > git://github.com/ceph/hadoop-common cephfs/branch-1.0 > > There is an old version of the Hadoop plugin in the Ceph tree which > will be removed shortly. Regarding the versions, development is taking > place in cephfs/branch-1.0 and in ceph.git master. We don't yet have a > system in place for dealing with compatibility across versions because > the code is in heavy development. If you are using the old version in the Ceph tree, you should be setting fs.ceph.blockSize rather than ceph.object.size. :) >> I would be interested in setting this parameter to values higher than 64MB, e.g. 256MB or 512MB similar to the values I have used for HDFS for increasing the performance of the TeraSort benchmark. Would these values be allowed and would they at all make sense for the mechanisms used in CEPH? > > I can't think of any reason why a large size would cause concern, but > maybe someone else can chime in? Yep, totally fine. -Greg -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
