RE: Oracle RAC on Win vs. Oracle on Linux

  • From: "Goulet, Richard" <Richard.Goulet@xxxxxxxxxxx>
  • To: "Niall Litchfield" <niall.litchfield@xxxxxxxxx>
  • Date: Tue, 23 Feb 2010 10:24:26 -0500

AH, I see we've sparked another HOLY WAR, bout time.  
 
    Well for one the Windows systems that we have around here are
getting on in age.  Yes they are Win2K and yes they are 32 bit because
that's the way they were built by our wonderful friends at Dell.  They
also predate all of us in the department with a lot of history on how &
why they were set up lost to the ether.  Yes their running RAC,  but
that's about where it ends.  There is no CRS or ASM running and believe
it or not you can actually see the datafiles on the san.  Really weird
to say the least.  There are 7 instances on each server & with only 16GB
total memory they have been struggling since I signed on.  Also why they
were built as RAC system has been lost to the ether as well.  The best
we can get from memories is that Dell recommended it to preclude
database unavaibility in the event of hardware failure (these machines
have only 1 power supply).  We're nearing the end of migrating them off
of RAC and Windowze onto Linux and single node, single instance.
 

Dick Goulet 
Senior Oracle DBA/NA Team Lead 
PAREXEL International 

 

________________________________

From: Niall Litchfield [mailto:niall.litchfield@xxxxxxxxx] 
Sent: Tuesday, February 23, 2010 4:12 AM
To: Goulet, Richard
Cc: rafiq9857@xxxxxxxxxxx; Robert Freeman; oracle list
Subject: Re: Oracle RAC on Win vs. Oracle on Linux


Hi Dick,
 
First of all let me say that none of what follows is intended as a
slight on either the decision you describe below which is perfectly fair
and reasonable, nor the skills and competence of your wider team about
which I know nothing. I'm really just using your post as a jumping off
point to remake some of my argument in the new Oak Table press book and
to comment on more general practice in the industry. 
 
The points you make (apart from the "blue screen of death") apply to
32bit Oracle on Windows. Strictly of course they also apply to 64bit
Oracle on 64bit windows and when 8Tb of memory becomes a limiting factor
for our databases then the same problems will apply there as well, this
day is a way off - I'm hoping past my retirement but I doubt it, I
expect to be seeing 128bit computing (and 64bit shops busy windowing
into a 128bit address space in a mad attempt to avoid just using the
right hardware and software in the first place then). 32bit windows is
limited by the architecture to a relatively few number of concurrent
sessions ( low hundreds typically) and to relatively low memory
requirements as you describe -- and because each new connection uses 1mb
of memory by default whether it's doing anything or not these two
restrictions have become rather limiting <rant> especially as web
developers can't close connections reliable when not needed</rant>.   
 
The proper solution here is not necessarily to jump ship to *nix, though
that might be a perfectly reasonable decision for other reasons, but
simply to move to 64bit computing of whatever flavour. After all it's
extremely likely that your server and os have been running on 64bit
hardware for some years now. What I do see often that really annoys me,
though again I'm not suggesting this is your specific suggestion, is
that *nix 64bit - especially Linux x86-64 - is superior to win32 because
of the process and memory limits of the latter. Well doh! It is true
that in a limited environment because of the process vs thread
architecture Linux x86 is superior to win32 but then I'd be amazed if
people were installing 32bit Linux either for much of the same reasons.
It really isn't the 90s any more. 
 
If you really mean that you have an actual blue screen of death that
frequently, it really ought to be resolvable and certainly shouldn't
have anything to do with Oracle itself since this is caused (primarily)
by kernel address space bugs in drivers or other kernel mode software
(so I guess crs could cause a BSOD). Your expectation should be that a
BSOD should never be seen on a server running windows 2003 or later and
rarely on windows 2000 and that any such occurrence should result in a
support ticket with either or both of the hardware vendor and/or
microsoft themselves. 
 
Robert's original question was about RAC. I'd go back here to the
comments in the other thread about RAC beng more complex and prone to
human error than vanilla Oracle, and add that because of the clusterware
and internetworking requirements it presents much more of an o/s
management challenge than a vanilla o/s install, for that reason
primarily I'd agree with the other posters who have commented upon where
the skills of the system administration staff lie. Windows RAC in the
hands of a Solaris SA is likely to be a disaster as is the reverse case.

 
  


On Tue, Feb 23, 2010 at 2:02 AM, Goulet, Richard
<Richard.Goulet@xxxxxxxxxxx> wrote:


        Rafiq,
         
            As I'm working in one of the premier (top 10) trials
companies to the pharma community we are moving all our
databases/applications off of Windows for Unix based operating systems.
These are validated, no problem.  Windows has two basic problems, memory
and processes.  Without a start up switch your limited to 3GB total
memory for Oracle, with the switch you can have another gb, but it uses
memory context switches which are a performance killer.  The second is
that Oracle on Windows is multithreaded within a single executable where
as Unix based systems have multiple processes again limiting capacity.
Our windows based databases are a real pain in the shorts, they are
constantly hitting that "blue screen of death" at least once a week.  As
it is after 1 June we will no longer support or validate a Windows
database.
         

        Dick Goulet 
        Senior Oracle DBA/NA Team Lead 
        PAREXEL International 

         

________________________________

        From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Mohammad Rafiq
        Sent: Monday, February 22, 2010 8:50 PM
        To: Robert Freeman; oracle list
        Subject: RE: Oracle RAC on Win vs. Oracle on Linux
        
        
        Robert,
         
        I don't agree that Window is evil. I seen problems with Windows
NT (mostly memory leak related)  but after handling Oracle databases on
Windows 2000 or newer version, it is quite stable. However it depends on
SA of Windows server how competent they are to configure and handle
Windows server.
         
        I am mostly supporting Oracle databases of various versions on
HP, RedHat Linux and Windows and did not find serious issues with
Windows 2000+ servers. Although it is not a preferred environment but
due vendor requirements for their application (specially for
pharmceutical industry which needs validated application/databases) we
need to put Oracle databases on Windows 2000/2003 servers.
         
        Regards
        Rafiq
         
         
        
________________________________

        Date: Mon, 22 Feb 2010 15:05:10 -0800
        From: robertgfreeman@xxxxxxxxx
        Subject: Oracle RAC on Win vs. Oracle on Linux
        To: oracle-l@xxxxxxxxxxxxx
        
        
        Anyone want to jump in on their preferred platform for RAC?
Personally I tend to lean towards Linux for stability purposes, but I'd
like your thoughts on why you prefer either platform for RAC.
Specifically why would you avoid windows (other than the fact that it's
evil), or would you?
        
        RF
        
        
         
        Robert G. Freeman
        Master Principle Consultant, Oracle Corporation
        Oracle ACE
        Author:
        Oracle Database 11g RMAN Backup and Recovery (Oracle Press) - ON
ITS WAY SOON!
        OCP: Oracle Database 11g Administrator Certified Professional
Study Guide (Sybex)
        Oracle Database 11g New Features (Oracle Press)
        Oracle Database 10g New Features (Oracle Press)
        Other various titles
        Blog: http://robertgfreeman.blogspot.com
<http://robertgfreeman.blogspot.com/>  



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-- 
Niall Litchfield
Oracle DBA
http://www.orawin.info

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