Re: dbms_resource_manager.calibrate_io - interpreting/comparing the results

From: Radoulov, Dimitre <cichomitiko_at_gmail.com>
Date: Fri, 09 Mar 2012 08:11:33 +0100
Message-ID: <4F59AD25.5010207_at_gmail.com>



Hi Anthony,

RAC 11.2.0.3.1 two nodes on RHEL5 x64 (no vmware) 128 15k rpm FC disks on SAN:

Two consecutive executions of DBMS_RESOURCE_MANAGER.CALIBRATE_IO (128, 10, iops, mbps, lat):

max_iops = 58392
latency  = 2
max_mbps = 891

max_iops = 58045

latency = 1
max_mbps = 877

We executed the procedure on an brand new empty database and there were few big (3T) bigfile empty tablespaces.

The first time I executed the procedure there were only the system/sysaux/undo and the temp tablespaces and they were really small (this was right after the database was created), the result was completely different (and that could be really misleading):

max_iops = 112431
latency  = 0
max_mbps = 2060



Best regards
Dimitre

On 07/03/2012 22:08, anthony Sanchez wrote:
> Hi Oracle folks,
> I'm relatively new to the capacity planning business (and oracle-L) and am
> looking for some other real world calibrate_io metrics to compare against.
> How do these metrics compare to what you've seen?
>
> I know it ultimately comes down to SLA's and what our storage vendor's
> promise (trying to get that info) but I'd like to have a frame of reference
> for comparison.
>
> I guess what I'm looking for is whether what I'm seeing is a Ford (Opel for
> some of you):
>
> 1) Focus
> 2) Mustang
> 3) Shelby GT500
> 4) other? :)
>
> Our system:
>
> Oracle 11.2.0.3 on RHEL5 x64 (virtualized via vmware)
> HP Left hand P4500 G2 120TB storage cluster with 120 1,000 GB 7.2K MDL SAS
> disk drives (RAID 10)
>
> *My script:*
> set serveroutput on
>
> declare
> l_latency integer;
> l_iops integer;
> l_mbps integer;
> begin
> dbms_resource_manager.calibrate_io (120,10,l_iops,l_mbps,l_latency);
> dbms_output.put_line('I/O Ops/sec = '||l_iops);
> dbms_output.put_line('Actual Latency = '||l_latency);
> dbms_output.put_line('MB/sec = '||l_mbps);
> end;
> /
>
> *Results:*
> sys_at_MUDRPRD> @calibrate_io.sql
> *I/O Ops/sec = 6922*
> *Actual Latency = 10*
> *MB/sec = 655*
>
> begin
> print_table('
> select max_iops,max_mbps,max_pmbps,latency,num_physical_disks from
> DBA_RSRC_IO_CALIBRATE
> ');
> end;
> /
>
> *MAX_IOPS : 6922*
> *MAX_MBPS : 655*
> *MAX_PMBPS : 372*
> *LATENCY : 10*
> *NUM_PHYSICAL_DISKS : 120*
> -----------------
>

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Received on Fri Mar 09 2012 - 01:11:33 CST

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