RE: SOS Alert

From: Mohan, Ross <MohanR_at_STARS-SMI.com>
Date: Fri, 22 Dec 2000 13:37:52 -0500
Message-Id: <10718.125270@fatcity.com>

This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible.

------_=_NextPart_001_01C06C46.4AC37D50
Content-Type: text/plain;

charset="iso-8859-1"

Interesting question! My stab in the dark, shot from the hip, wild-ass guess is as follows:

Since modern OSes can cache code segments via shared libraries, there is a *very high* read to write ratio (i.e. it is read once from disk into OS cache, and re-used from there by many folks ) and so the "read from disk" is not a significant performance issue.

Where disk config *would* become significant would be in case of failure: What is faster? Recover by backup? Software re-install? And, what is more likely to fail? Software striped across ten disks _without_ a mirror is more likely to become unavailable than software located on one disk, just because of the inverse additive effect of individual disk MTBFs in a stripe set. So, if you must stripe app binaries, mirror them.

There are other comments about code re-use in the OS, but if i start on those, this won't be a "shot from the hip" anymore.

Maybe Eric Pierce can Google us up some pithy and provocative URLs to keep us thinking on this topic!

hth

Ross

-----Original Message-----
From: VIVEK_SHARMA [mailto:VIVEK_SHARMA_at_infy.com] Sent: Friday, December 22, 2000 12:21 PM To: Multiple recipients of list ORACLE-L Subject: RE: SOS Alert

A related Basic Qs.

Can the Application Software ( Banking Application of pro*c Executables in this Case) be put on Striped Disks belonging to the APP Server ?

Does it Have any Certain Negative performance impacts ? OR is Performance the Same whether the Application Lies on Striped Disks or NON-Striped Disks ?

------_=_NextPart_001_01C06C46.4AC37D50
Content-Type: text/html;

charset="iso-8859-1"

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
<HTML>
<HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1">
<META NAME="Generator" CONTENT="MS Exchange Server version 5.5.2653.12">
<TITLE>RE: SOS Alert </TITLE>
</HEAD>
<BODY>

Interesting question! My stab in the dark, shot from the hip, wild-ass guess is as follows:


Since modern OSes can cache code segments via shared 
 libraries, there is a *very high* read to write ratio (i.e. 
 it is read once from disk into OS cache, and re-used from 
 there by many folks ) and so the "read from disk" is not a 
 significant performance issue.


Where disk config *would* become significant would be in case 
 of failure: What is faster? Recover by backup? Software 
 re-install? And, what is more likely to fail?  Software 
 striped across ten disks _without_ a mirror is more likely to 
 become unavailable than software located on one disk, just 
 because of the inverse additive effect of individual disk 
 MTBFs in a stripe set.  So, if you must stripe app binaries, 
 mirror them. 


There are other comments about code re-use in the OS, but 
 if i start on those, this won't be a "shot from the hip" 
 anymore. 


Maybe Eric Pierce can Google us up some pithy and provocative 
 URLs to keep us thinking on this topic!


hth


Ross


-----Original Message-----
 From: VIVEK_SHARMA [<A HREF="mailto:VIVEK_SHARMA_at_infy.com">mailto:VIVEK_SHARMA_at_infy.com</A>]
 Sent: Friday, December 22, 2000 12:21 PM
 To: Multiple recipients of list ORACLE-L
 Subject: RE: SOS Alert 

 

A related Basic Qs.


Can the Application Software (  Banking Application of pro*c Executables  in
 this Case) be put on Striped Disks belonging to the APP Server ? 


Does it Have any Certain Negative performance impacts ?
 OR is Performance the Same whether the  Application Lies on Striped Disks or
Received on Fri Dec 22 2000 - 12:37:52 CST