On Thursday, March 14, 2013 at 8:20 AM, Sage Weil wrote: > On Thu, 14 Mar 2013, Huang, Xiwei wrote: > > Hi, all, > > I noticed that CephFS fails to support Direct IO for blocks larger than 8MB, say: > > sudo dd if=/dev/zero of=mnt/cephfs/foo bs=16M count=1 oflag=direct > > dd: writing `mnt/cephfs/foo: Bad address > > 1+0 records in > > 0+0 records out > > 0 bytes (0 B) copied, 0.213948 s, 0.0 kB/s > > My version Ceph is 0.56.1. > > ??I also found the bug has been already reported as Bug #2657. > > Is this fixed in the new 0.58 version? > > > > I'm pretty sure this is a problem on the kernel client side of things, not > the server side (which by default handles writes up to ~100MB or so). I > suspect it isn't terribly difficult to fix, but hasn't been prioritized... > > sage My guess too. Are direct IO writes of that size a common thing or of great import to you? Either way, a comment on the tracker saying you've run into it will promote it up when we're doing bug scrubs and backlog reviews. :) -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
