Looks like these could be useful - "trace-cmd record -e smb3_write* -e smb3_read*" root@smf-Thinkpad-P51:~/cifs-2.6# echo 0 > /proc/fs/cifs/Stats root@smf-Thinkpad-P51:~/cifs-2.6# dd if=/dev/urandom of=/mnt1/8M count=8000 bs=1024 8000+0 records in 8000+0 records out 8192000 bytes (8.2 MB, 7.8 MiB) copied, 0.0694953 s, 118 MB/s root@smf-Thinkpad-P51:~/cifs-2.6# trace-cmd show # tracer: nop # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | dd-21812 [006] .... 85789.843915: smb3_write_enter: xid=0 sid=0x158347 tid=0x6c217504 fid=0x4e73e0d5 offset=0x0 len=0x400000 dd-21812 [006] .... 85789.845676: smb3_write_enter: xid=0 sid=0x158347 tid=0x6c217504 fid=0x4e73e0d5 offset=0x400000 len=0x3d0000 cifsd-16822 [001] .... 85789.848381: smb3_write_done: xid=0 sid=0x158347 tid=0x6c217504 fid=0x4e73e0d5 offset=0x0 len=0x400000 cifsd-16822 [003] .... 85789.850297: smb3_write_done: xid=0 sid=0x158347 tid=0x6c217504 fid=0x4e73e0d5 offset=0x400000 len=0x3d0000 root@smf-Thinkpad-P51:~/cifs-2.6# cat /proc/fs/cifs/Stats Resources in use CIFS Session: 1 Share (unique mount targets): 2 SMB Request/Response Buffer: 1 Pool size: 5 SMB Small Req/Resp Buffer: 1 Pool size: 30 Operations (MIDs): 0 0 session 0 share reconnects Total vfs operations: 6 maximum at one time: 1 1) \\localhost\scratch SMBs: 12 Bytes read: 0 Bytes written: 8192000 Open files: 0 total (local), 1 open on server TreeConnects: 0 total 0 failed TreeDisconnects: 0 total 0 failed Creates: 3 total 0 failed Closes: 3 total 0 failed Flushes: 0 total 0 failed Reads: 0 total 0 failed Writes: 2 total 0 failed -- Thanks, Steve