Hi, I was trying to test write performance of Ceph, using direct I/O. $ dd if=/dev/zero of=/mnt/ceph/my.dat bs=1M count=1 oflag=direct But dd is just stuck without doing any write. Without oflag, write is done fine. In the above example, I used Ceph kernel module 0.20, built on kernel 2.6.32. I also tried Ceph fuse client to mount. In this case, the above dd command gives me: "dd: opening `/mnt/ceph/my.dat': Invalid argument" Is it because Ceph does not support direct I/O? I'm using ceph 0.46, installed using Debian release package. There are three OSDs, 1 Mon and 1 MDS in the cluster. Any help or clarification is appreciated. Chang -- 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
