Finding Oracle Homes which Oracle instances are using on Linux

Tanel Poder

2011/02/28

I had a question about how to quickly identify which Oracle process runs out of which ORACLE_HOME on Linux.

I have uploaded a little script for that – it’s basically looking up all PMON process IDs and then using /proc/PID/exe link to find out where is the oracle binary of a running process located.

You may have to run this as root (as on some Linux versions I get “ls: cannot read symbolic link: Permission denied” error even when running this command as the owner of all Oracle homes (it seems to happen when your users UID and primary GID are different than thet setuid/setgid bits on the oracle binary):

oracle@linux03:~$ sudo ./findhomes.sh
   PID NAME                 ORACLE_HOME
  4421 asm_pmon_+ASM        /u01/app/oracle/product/11.2.0/db_1/
  4545 ora_pmon_demo112     /u01/app/oracle/product/11.2.0/dbhome_1/
  4547 ora_pmon_test112     /u01/app/oracle/product/11.2.0/dbhome_1/

You can use a similar approach on other Unixes too where the executable location or current working directory (CWD) is externalized in the /proc filesystem – or just use pmap to get this info instead.