[Search for users] [Overall Top Noters] [List of all Conferences] [Download this site]

Conference turris::digital_unix

Title:	DIGITAL UNIX(FORMERLY KNOWN AS DEC OSF/1)
Notice:	Welcome to the Digital UNIX Conference
Moderator:	SMURF::DENHAM

Created:	Thu Mar 16 1995
Last Modified:	Fri Jun 06 1997
Last Successful Update:	Fri Jun 06 1997
Number of topics:	10068
Total number of notes:	35879

8879.0. "nfs slow performance" by DAIVC::BENNY (I am the only one) Wed Feb 19 1997 04:14

Dear all,

I have a problem with System performance while the SAP Application activated
using AS 4100 Rackmount (2 units)
The configuration of the system :

- AlphaServer 8400 as a SAP Database Server that connected to SW800.
- AlphaServer 4100 Rackmount as a SAP Application Server that mounted several
  file system from Database Server using NFS.
- Operating System D-UNIX 3.2G
- Firmware Revision 3.8 for both Machine
- 2 DE500-AA installed at 4100 and it set as 10MB.

When all machine up, there was no problem with the performance of AS4100.
But after my customer activated the SAP Application, the performance of 
system become slowed. I tried to checked it using netstat, and the information
of network collusion was very high.

This problem accoured while application activated. But it become normally when
deactivated application.

Does anybody has nearly the same problem ..?
Please reply ASAP..

rgrds
daivc::ramadoni

T.R Title User Personal
Name Date Lines

8879.1 Machines under load always have decreased performance NETRIX::"[email protected]" Brian Haley Wed Feb 19 1997 10:39 20

T.R	Title	User	Personal Name	Date	Lines
8879.1	Machines under load always have decreased performance	NETRIX::"[email protected]"	Brian Haley	`Wed Feb 19 1997 10:39`	20
	Hi, It's sort-of a fact of life that when you start running an application and put the machine under load that other performance aspects degrade accordingly. Take some vmstat or ps snapshots and see how loaded the machine is. > I tried to checked it using netstat, and the information > of network collusion was very high. Did you mean _collision_ or just "the network was busy"? I'd assume when SAP is running, the NFS usage increases, causing a lot of network traffic. That seems normal to me. Both of the machines mentioned can easily swamp a 10MB Ethernet segment, since you have DE500s, why don't you run them at 100MB (or 200), assuming you have support for it in your concentrator? Maybe someone else can respond with some SAP tuning info... -Brian [Posted by WWW Notes gateway]

Hi,

It's sort-of a fact of life that when you start running an application
and put the machine under load that other performance aspects degrade
accordingly.  Take some vmstat or ps snapshots and see how loaded the
machine is.

> I tried to checked it using netstat, and the information
> of network collusion was very high.

Did you mean _collision_ or just "the network was busy"?  I'd assume when
SAP is running, the NFS usage increases, causing a lot of network traffic.
That seems normal to me.  Both of the machines mentioned can easily swamp
a 10MB Ethernet segment, since you have DE500s, why don't you run them at
100MB (or 200), assuming you have support for it in your concentrator?

Maybe someone else can respond with some SAP tuning info...

-Brian
[Posted by WWW Notes gateway]