Hi all, I have a question regarding to RBD performance. Recently I test RBD in 2 cluster, using dd if=/dev/zero of=/dev/rbd5 bs=4M count=1024 oflag=direct. I got 33.4MB/s in one cluster , however got only 6MB/s in the other cluster. I have confirmed that the network bandwidth is ok. and osd bench shows around 32 ~ 40 MB/s on all OSD. Is this performance normal? if not , how can I troubleshoot it? I have move journal to ramdisk for testing and get performance boost to 7x MB/s. Does this means the HDD is the bottleneck ? The other cluster that got 33.4 MB/s , it's osd bench shows around 44MB/s. The major difference between those two cluster is the better performed one use SAS with RAID controller the other use SATA with no RAID control. Thanks. Regards, Leander Yu. -- 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
