How to Identify OS or Oracle 64 bit or 32 bit on Unix

It is very common question which version of oracle I need to install. 32 bit or 64 bit? As a 64-bit operating system can support either a 32-bit database or a 64-bit database. A 32-bit operating system cannot support a 64-bit database. So, version identification of the OS is necessary prior to install oracle. The following procedure will hopefully help you.

Check whether OS is 64 bit or 32 bit.
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On Solaris,

SQL> !/usr/bin/isainfo -kv
64-bit amd64 kernel modules

SQL> !/usr/bin/isainfo -v
64-bit amd64 applications
cx16 mon sse3 pause sse2 sse fxsr mmx cmov amd_sysc cx8 tsc fpu
32-bit i386 applications
cx16 mon sse3 pause sse2 sse fxsr mmx cmov sep cx8 tsc fpu

This output tells us that solaris operating systems allow co-existence of 32-bit and 64-bit files.

On AIX,
$ getconf -a | grep KERN
$ file /usr/lib/boot/unix*
On Linux,

On HP-UX,
/usr/bin/ getconf KERNEL_BITS
/usr/bin/file /stand/vmunix

On linux,

$uname -a
Linux debian 2.6.18-4-686 #1 SMP Wed May 9 23:03:12 UTC 2007 i686 GNU/Linux

If the output is x86_64 then 64-bit and i686 or similar for 32-bit.

On linux you can also see by getconf LONG_BIT.
On 64 bit,
$ getconf LONG_BIT
64

On 32 bit,
$ getconf LONG_BIT
32
On windows,

Start>All Programs>accessories> System Tools>System Information>look for under System summary.

Or start>run>dixdiag>Then check for WHQL digital signature.

Determine of whether Oracle Software is 32 bit or 64 bit.
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Method 1:
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Go to $ORACLE_HOME/bin and see.

# cd $ORACLE_HOME/bin
# file oracle
oracle: ELF 64-bit LSB executable AMD64 Version 1, dynamically linked, not stripped

Here it comes 64 bit and hence oracle software is 64 bit. If the output of the "file oracle" command does not say 64-bit explicitly then you are running 32-bit Oracle.

If you had 32 bit oracle software installed then output will be like,

oracle@sol:/db/oracle/bin$ file oracle
oracle: setuid setgid ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked (uses shared libs), not stripped

Method 2:
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Log on to SQL*plus and see the banner.

-bash-3.00$ sqlplus / as sysdba

SQL*Plus: Release 10.2.0.2.0 - Production on Thu May 15 02:50:37 2008

Copyright (c) 1982, 2005, Oracle. All Rights Reserved.


Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.2.0 - Production
With the Partitioning, OLAP and Data Mining options

Method 3:Query from v$version.
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sys@ARJU> select * from v$version;

BANNER
----------------------------------------------------------------
Oracle Database 10g Enterprise Edition Release 10.2.0.2.0 - Prod
PL/SQL Release 10.2.0.2.0 - Production
CORE 10.2.0.2.0 Production
TNS for Solaris: Version 10.2.0.2.0 - Production
NLSRTL Version 10.2.0.2.0 - Production

Method 4: Check for lib, lib32
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1) $ORACLE_HOME/lib32
2) $ORACLE_HOME/lib

If the two directories $ORACLE_HOME/lib32 and $ORACLE_HOME/lib are existing then it is 64 bit.

If there is only an ORACLE_HOME/lib directory then it is 32 bit client.