LinuxQuestions.org
Share your knowledge at the LQ Wiki.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Newbie
User Name
Password
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!

Notices


Reply
  Search this Thread
Old 12-03-2009, 12:02 AM   #1
vinaytp
Member
 
Registered: Apr 2009
Location: Bengaluru, India
Distribution: RHEL 5.4, 6.0, Ubuntu 10.04
Posts: 704

Rep: Reputation: 55
RHEL 32 bit OS


Hi all...

Will Oracle 10g 64-bit database run on RHEL 5.4 32 bit OS ?

Because for our Oracle applicatons to run we need RHEL 32 bit OS...

Thanks in advnace...

Last edited by vinaytp; 12-03-2009 at 12:10 AM.
 
Old 12-03-2009, 02:19 AM   #2
acid_kewpie
Moderator
 
Registered: Jun 2001
Location: UK
Distribution: Gentoo, RHEL, Fedora, Centos
Posts: 43,417

Rep: Reputation: 1975Reputation: 1975Reputation: 1975Reputation: 1975Reputation: 1975Reputation: 1975Reputation: 1975Reputation: 1975Reputation: 1975Reputation: 1975Reputation: 1975
no, you can't run 64 bit software on a 32 bit operating system. The opposite way round works, but not that way.
 
Old 12-03-2009, 07:54 AM   #3
vinaytp
Member
 
Registered: Apr 2009
Location: Bengaluru, India
Distribution: RHEL 5.4, 6.0, Ubuntu 10.04
Posts: 704

Original Poster
Rep: Reputation: 55
Quote:
Originally Posted by acid_kewpie View Post
no, you can't run 64 bit software on a 32 bit operating system. The opposite way round works, but not that way.
Thanks a lot acid_kewpie,

Is it necessary to have two servers one for Database with 64 bit OS and another for apps with 32 bit OS ?
 
Old 12-03-2009, 08:24 AM   #4
18Googol2
Member
 
Registered: Oct 2008
Distribution: FreeBSD, RedHat, Centos, Solaris, AIX
Posts: 34

Rep: Reputation: 17
Quote:
Originally Posted by vinaytp View Post
Thanks a lot acid_kewpie,

Is it necessary to have two servers one for Database with 64 bit OS and another for apps with 32 bit OS ?
Yes, sure you can
 
Old 12-03-2009, 08:54 AM   #5
johnsfine
LQ Guru
 
Registered: Dec 2007
Distribution: Centos
Posts: 5,286

Rep: Reputation: 1190Reputation: 1190Reputation: 1190Reputation: 1190Reputation: 1190Reputation: 1190Reputation: 1190Reputation: 1190Reputation: 1190
Quote:
Originally Posted by vinaytp View Post
Is it necessary to have two servers one for Database with 64 bit OS and another for apps with 32 bit OS ?
No. 64-bit RHEL or Centos can run 32 bit applications just fine (generally better than a 32 bit Linux can run 32 bit applications).

If you were severely short of ram or disk space, you wouldn't want to have both 32 and 64 bit versions of all the .so files in use at once. But if you were even moderately short on ram or disk space, I don't think you would want a 64 bit database.

Quote:
Originally Posted by vinaytp View Post
for our Oracle applicatons to run we need RHEL 32 bit OS.
What is the basis for that statement?

In Debian based Linux, there seem to be rare cases where you need to go all the way to a fake root to get 32 bit software working in a 64 bit system. But you can get it working even in Debian. RHEL and Centos have less issues with 32 bit applications in a 64 bit OS.

Last edited by johnsfine; 12-03-2009 at 08:58 AM.
 
Old 12-03-2009, 08:59 AM   #6
vinaytp
Member
 
Registered: Apr 2009
Location: Bengaluru, India
Distribution: RHEL 5.4, 6.0, Ubuntu 10.04
Posts: 704

Original Poster
Rep: Reputation: 55
Quote:
Originally Posted by johnsfine View Post
No. 64-bit RHEL or Centos can run 32 bit applications just fine (generally better than a 32 bit Linux can run 32 bit applications).
Thanks johnsfine,

But the problem is Oracle Applications prerequisites document specifies, it can run only on 32 bit OS if the machine architecture is 64 bit..

Below is the Note specified in Prerequisite document...

Quote:
Note:
You can only install Oracle Applications on an x86-64 architecture server if the operating system is 32-bit Linux or Windows. If your operating system is 64-bit, contact your operating system vendor to obtain a 32-bit operating system before installing Oracle Applications.

Last edited by vinaytp; 12-03-2009 at 09:01 AM.
 
Old 12-03-2009, 05:48 PM   #7
chrism01
LQ Guru
 
Registered: Aug 2004
Location: Sydney
Distribution: Centos 6.9, Centos 7.3
Posts: 17,374

Rep: Reputation: 2383Reputation: 2383Reputation: 2383Reputation: 2383Reputation: 2383Reputation: 2383Reputation: 2383Reputation: 2383Reputation: 2383Reputation: 2383Reputation: 2383
In that case you either run 32 bit Oracle DB, or get another system..
It's pretty strange though. On RHEL/Centos (5.x), both sets of libs (32 & 64 bit) are installed on a 64 bit version, and usually everything (32 & 64 bit) apps run fine.
 
Old 12-06-2009, 09:31 AM   #8
resetreset
Senior Member
 
Registered: Mar 2008
Location: Cyberspace
Distribution: Dynebolic, Ubuntu 10.10
Posts: 1,340

Rep: Reputation: 62
To John Fine: I'm curious, why do you say this?: " generally better than a 32 bit Linux can run 32 bit applications" - wouldn't the mode switch to 32-bit mode made every time there was a task switch to that program slow down the system?
 
Old 12-06-2009, 11:45 AM   #9
johnsfine
LQ Guru
 
Registered: Dec 2007
Distribution: Centos
Posts: 5,286

Rep: Reputation: 1190Reputation: 1190Reputation: 1190Reputation: 1190Reputation: 1190Reputation: 1190Reputation: 1190Reputation: 1190Reputation: 1190
Quote:
Originally Posted by resetreset View Post
To John Fine: I'm curious, why do you say this?: " generally better than a 32 bit Linux can run 32 bit applications" - wouldn't the mode switch to 32-bit mode made every time there was a task switch to that program slow down the system?
I have tested some 32 bit applications on both 32 bit and 64 bit Linux on the same hardware. There is a slight advantage to 64 bit Linux. I don't know enough internal details to know why. I don't know how the switch to kernel mode with/without the switch of address size compares. I don't know whether that is a tiny disadvantage to a 64 bit OS (as you might expect) that is balanced by some factor I know even less about. Subtle differences can be hard to understand or quantify.

I have tested some 32 bit applications on both 32 bit and 64 bit Windows XP. The difference is more significant. On systems with 2 GB to 3.X GB of ram, XP 32 gets very stupid about the way file caching works because of bad design combined with limited kernel virtual address space. XP 64 has the same "bad" design, but that design does no harm as long as kernel virtual address space is a significant multiple larger than physical memory. 32 bit applications that depend on the kernel to do file caching well run much better on XP64 than on XP32. (Obviously on systems with over 3.X GB of ram, XP 32 is license limited to not use the extra ram, so its file caching gets a LOT worse).


I don't know whether 32 bit Linux does a good job with file caching on systems with large ram. Doing so would be harder due to limited kernel virtual address space. But I don't know Linux internals well enough to know whether 32 bit Linux does large ram file caching well despite the difficulties, or whether file caching is better in Linux64 than in Linux32.

Also, 32 bit Linux with up to 896MB of ram keeps all physical ram mapped into the kernel, so it can directly work on I/O operations in support of processes other than the one whose virtual address space is currently mapped. But 32 bit Linux with over 896MB of ram must do extra mapping every time it needs to access buffers for any process that might not by currently mapped.

I'm pretty sure 64 bit Linux has simplified back to the design that 32 bit Linux could only use with under 896MB of ram. That simpler design would be practical in 64 bit Linux all the way up to around 100000GB of physical ram. So it may save a bunch of remapping operations and related TLB misses.

Last edited by johnsfine; 12-06-2009 at 12:13 PM.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
[SOLVED] Assistance needed to set up RHEL 64-bit as a YUM Proxy server for 32-bit also. xenner Linux - Newbie 7 10-19-2009 08:50 PM
Major Changes between 32 bit RHEL and 64 Bit RHEL? sahil.jammu Linux - Newbie 2 07-03-2009 01:31 AM
RE: RHEL 4.6 32-Bit installation pslim123 Linux - Newbie 2 05-21-2009 01:20 AM
Unable to boot to RHEL 4 32 bit after installing RHEL 64 - bit raj_ksrt Linux - Software 1 04-27-2009 09:44 AM
Possible to have virtual machine in RHEL 5.1 run RHEL 4.0-1 ES (64-bit) maryjane Linux - Newbie 1 10-20-2008 12:04 PM

LinuxQuestions.org > Forums > Linux Forums > Linux - Newbie

All times are GMT -5. The time now is 04:00 AM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration