dbms_resource_manager.calibrate_io, strange numbers

From: D'Hooge Freek <Freek.DHooge_at_uptime.be>
Date: Wed, 5 Oct 2011 15:25:50 +0200
Message-ID: <4814386347E41145AAE79139EAA3989817A8BC0B07_at_ws03-exch07.iconos.be>

Hi,

To enable auto dop on a new system, I ran the calibrate_io procedure from the dbms_resource_manager package. However the results are a bit strange.
The actual latency is reported as 0 and so is the max_mbps. The max_pmbps however is set to 186.

Monitoring with collectl showed network troughput of arround 230 MB/s

Db version is 11.2.0.2 (64bit) on OL 5.4 (64bit). Storage is NetApp, accessed via dNFS (using 2 1 Gbit/s connections)

I searched MOS and google, but no real bugs popped up. What can explain the actual latency and the max_mbps to be set to 0?

SQL> _at_io_callibration.sql
SQL> set serveroutput on
SQL> set timing on
SQL> set echo on
SQL>
SQL> DECLARE

  2

  3    l_actual_latency    integer;
  4    l_max_iops          integer;
  5    l_max_mbps          integer;

  6
  7 BEGIN
  8
  9 dbms_resource_manager.calibrate_io

 10      ( num_physical_disks  =>  30,
 11        max_latency         =>  20,
 12        max_iops            =>  l_max_iops,
 13        max_mbps            =>  l_max_mbps,
 14        actual_latency      =>  l_actual_latency
 15      );

 16

 17    dbms_output.put_line ('max_iops = ' || l_max_iops);
 18    dbms_output.put_line ('actual_latency  = ' || l_actual_latency);
 19    dbms_output.put_line('max_mbps = ' || l_max_mbps);

 20
 21 END;
 22 /

max_iops = 11750
actual_latency = 0
max_mbps = 0

PL/SQL procedure successfully completed.

Elapsed: 00:53:20.45

SQL>
SQL>
SQL> select * from gv$io_calibration_status;

   INST_ID STATUS        CALIBRATION_TIME


---------- ------------- ---------------------------------------------------------------------------

         1 READY         05-OCT-11 02.56.40.929 PM

Elapsed: 00:00:00.00

SQL>
SQL> set linesize 150
SQL> column start_time format a30
SQL> column end_time format a30
SQL> column num_physical_disks format 9999 heading NPD
SQL> select * from dba_rsrc_io_calibrate;

START_TIME                     END_TIME                         MAX_IOPS   MAX_MBPS  MAX_PMBPS    LATENCY   NPD


------------------------------ ------------------------------ ---------- ---------- ---------- ---------- -----

05-OCT-11 02.03.20.489842 PM   05-OCT-11 02.56.40.928773 PM        11750          0        186          0    30

Elapsed: 00:00:00.00

Kind regards,

Freek D'Hooge
Uptime
Oracle Database Administrator
email: freek.dhooge_at_uptime.be
tel +32(0)3 451 23 82
http://www.uptime.be
disclaimer: www.uptime.be/disclaimer

--

http://www.freelists.org/webpage/oracle-l Received on Wed Oct 05 2011 - 08:25:50 CDT