On Mon, Feb 6, 2017 at 3:18 AM, kefu chai <tchaikov@xxxxxxxxx> wrote: > On Sat, Feb 4, 2017 at 7:18 AM, Ming Lin <minggr@xxxxxxxxx> wrote: >> Hi, >> >> With a one monitor one OSD test setup(osd pool default size = 1), I >> captured the packets with tshark. >> pcap.out file: https://ufile.io/43c78 >> >> The test I did was: >> dd if=tmp.txt bs=512 count=1 of=/dev/rbd0 oflag=direct >> >> About 350 packets were captured just for above simple "dd" command. >> >> If you open the file with wireshark, you'll see packet #41 is the data packet. >> "192.168.122.1" is the OSD and "192.168.122.131" is the rbd client. >> >> What are other packets? > > you can set "debug-ms=1" and probably set "log_file" to a writable > path, then check the log. Got it. The other packets were actually from systemd-udevd doing read on the background. I added a debug in the krbd driver. Here is the trace. [ 90.206486] CPU: 0 PID: 1382 Comm: systemd-udevd Tainted: G OE 4.10.0-rc6+ #291 [ 90.206488] Call Trace: [ 90.206493] dump_stack+0x63/0x89 [ 90.206497] rbd_queue_rq+0x85/0x90 [rbd] [ 90.206499] blk_mq_dispatch_rq_list+0xdb/0x1f0 [ 90.206500] blk_mq_process_rq_list+0x122/0x140 [ 90.206501] __blk_mq_run_hw_queue+0xae/0xc0 [ 90.206502] blk_mq_run_hw_queue+0x95/0xc0 [ 90.206503] blk_mq_insert_requests+0xdc/0x1c0 [ 90.206504] blk_mq_flush_plug_list+0x127/0x140 [ 90.206506] blk_flush_plug_list+0xc7/0x220 [ 90.206507] blk_finish_plug+0x2c/0x40 [ 90.206510] __do_page_cache_readahead+0x19c/0x240 [ 90.206511] force_page_cache_readahead+0xa2/0x100 [ 90.206512] page_cache_sync_readahead+0x3f/0x50 [ 90.206514] generic_file_read_iter+0x579/0x7c0 [ 90.206517] ? _copy_to_user+0x2d/0x40 [ 90.206519] blkdev_read_iter+0x37/0x40 [ 90.206521] __vfs_read+0xbd/0x110 [ 90.206522] vfs_read+0x8c/0x130 [ 90.206524] SyS_read+0x46/0xa0 [ 90.206525] ? SyS_lseek+0x87/0xb0 [ 90.206528] entry_SYSCALL_64_fastpath+0x1e/0xad -- 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