Re: Performance with 2 AMD/Opteron 2.6Ghz and 8gig - Mailing list pgsql-performance

Luke,

Yeah, I read those results, and I'm very disappointed with my results
from the MSA1500. I would however be interested in other people's
bonnie++ and benchmarksql results using a similar machine (2 cpu dual
core opteron) with other "off the shelf" storage systems
(EMC/Netapp/Xyratex/../). Could you run benchmarksql against that
machine with the 16 SATA disk and 3Ware 9550SX SATA RAID adapters? It
would be *very* interesting to see how the I/O performance correlates to
benchmarksql (postgres) transaction throughout.

/Mikael

-----Original Message-----
From: Luke Lonergan [mailto: LLonergan@greenplum.com]
Sent: den 28 juli 2006 11:17
To: Mikael Carneholm; Kjell Tore Fossbakk;
pgsql-performance@postgresql.org
Subject: RE: [PERFORM] Performance with 2 AMD/Opteron 2.6Ghz and 8gig

Mikael,

> -----Original Message-----
> From: Mikael Carneholm [mailto:Mikael.Carneholm@WirelessCar.com]
> Sent: Friday, July 28, 2006 2:05 AM
>
> My bonnie++ results are found in this message:
> http://archives.postgresql.org/pgsql-performance/2006-07/msg00164.php
>

Apologies if I've already said this, but those bonnie++ results are very
disappointing.  The sequential transfer rates between 20MB/s and 57MB/s
are slower than a single SATA disk, and your SCSI disks might even do
80MB/s sequential transfer rate each.

Random access is also very poor, though perhaps equal to 5 disk drives
at 500/second.

By comparison, we routinely get 950MB/s sequential transfer rate using
16 SATA disks and 3Ware 9550SX SATA RAID adapters on Linux.

On Solaris ZFS on an X4500, we recently got this bonnie++ result on 36
SATA disk drives in RAID10 (single thread first):

Version  1.03       ------Sequential Output------    --Sequential Input-
--Random-
                    -Per Chr-  --Block--  -Rewrite-  -Per Chr-
--Block--  --Seeks--
Machine        Size K/sec  %CP K/sec  %CP K/sec  %CP K/sec  %CP K/sec
%CP /sec %CP
thumperdw-i-1   32G 120453  99 467814  98 290391  58 109371  99 993344
94 1801   4
                    ------Sequential Create------ --------Random
Create--------
                    -Create-- --Read--- -Delete-- -Create-- --Read---
-Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
/sec %CP
                 16 +++++ +++ +++++ +++ +++++ +++ 30850  99 +++++ +++
+++++ +++

Bumping up the number of concurrent processes to 2, we get about 1.5x
speed reads of RAID10 with a concurrent workload (you have to add the
rates together):

Version  1.03       ------Sequential Output------   --Sequential Input-
--Random-
                    -Per Chr- --Block--  -Rewrite-  -Per Chr-  --Block--
--Seeks--
Machine        Size K/sec  %CP K/sec  %CP K/sec  %CP K/sec  %CP K/sec
%CP  /sec %CP
thumperdw-i-1   32G 111441  95 212536  54 171798  51 106184  98 719472
88  1233   2
                    ------Sequential Create------ --------Random
Create--------
                    -Create-- --Read--- -Delete-- -Create-- --Read---
-Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
/sec %CP
                 16 26085  90 +++++ +++  5700  98 21448  97 +++++ +++
4381  97

Version  1.03       ------Sequential Output------   --Sequential Input-
--Random-
                    -Per Chr-  --Block--  -Rewrite-  -Per Chr-
--Block--   --Seeks--
Machine        Size K/sec  %CP K/sec  %CP K/sec  %CP K/sec  %CP K/sec
%CP  /sec %CP
thumperdw-i-1   32G 116355  99 212509  54 171647  50 106112  98 715030
87  1274   3
                    ------Sequential Create------ --------Random
Create--------
                    -Create-- --Read--- -Delete-- -Create-- --Read---
-Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
/sec %CP
                 16 26082  99 +++++ +++  5588  98 21399  88 +++++ +++
4272  97

So that's 2500 seeks per second, 1440MB/s sequential block read, 212MB/s
per character sequential read.

- Luke