All the log files related to clusterware processes can be found in the "$GRID_HOME/logs"
directory. So, if there is some problem with the clusterware you could check
all the log files in the directory.


But mining data from all the log files is difficult. So, in order
to ease of this difficulty in 11gR2 you can use the "diagcollection.pl"
script to collect diagnostic data.

Run the diagcollection.pl script as the root user to collect diagnostic information
from an Oracle Clusterware installation. The diagnostics provide additional information
so that Oracle Support Services can resolve problems. Run this script from the
operating system prompt as follows, where CRS_home is the home directory of your Oracle
Clusterware installation:

# Invoke this utility as the root user.
# CRS_home/bin/diagcollection.pl --collect

[root@rac1 ~]# /u01/app/11.2.0/grid/bin/diagcollection.pl --collect
Code:
Production Copyright 2004, 2008, Oracle.  All rights reserved
Cluster Ready Services (CRS) diagnostic collection tool
The following CRS diagnostic archives will be created in the local directory.
crsData_rac1_20130206_0017.tar.gz -> logs,traces and cores from CRS home. 
Note: core files will be packaged only with the --core option.
ocrData_rac1_20130206_0017.tar.gz -> ocrdump, ocrcheck etc
coreData_rac1_20130206_0017.tar.gz -> contents of CRS core files in text format

osData_rac1_20130206_0017.tar.gz -> logs from Operating System
Collecting crs data
/bin/tar: log/rac1/cssd/ocssd.log: file changed as we read it
/bin/tar: log/rac1/ctssd/octssd.log: file changed as we read it
Collecting OCR data
Collecting information from core files
No corefiles found
Collecting OS logs
[root@rac1 ~]# ll
Code:
total 14720
-rw------- 1 root root     2946 Aug 23 21:21 anaconda-ks.cfg
-rw-r--r-- 1 root root 14785218 Feb  6 00:17 crsData_rac1_20130206_0017.tar.gz
drwxr-xr-x 4 root root     4096 Feb  3 16:21 Desktop
-rw-r--r-- 1 root root    42129 Aug 23 21:20 install.log
-rw-r--r-- 1 root root     5259 Aug 23 21:20 install.log.syslog
-rw-r--r-- 1 root root    10960 Feb  6 00:18 ocrData_rac1_20130206_0017.tar.gz
-rw-r--r-- 1 root root   171884 Feb  6 00:18 osData_rac1_20130206_0017.tar.gz
-rwxr-x--- 1 root root      696 Jan 26 14:07 root.sh.racnode1.AFTER_INSTALL
To clean the collected data use the "--clean" option.

[root@rac1 ~]# /u01/app/11.2.0/grid/bin/diagcollection.pl --clean
Code:
Production Copyright 2004, 2008, Oracle.  All rights reserved
Cluster Ready Services (CRS) diagnostic collection tool
Cleaning up tar and gzip files
Done
[root@rac1 ~]# ll
total 88
-rw------- 1 root root 2946 Aug 23 21:21 anaconda-ks.cfg
drwxr-xr-x 5 root root 4096 Feb 6 00:19 cfgtoollogs
drwxr-xr-x 4 root root 4096 Feb 3 16:21 Desktop
drwxr-xr-x 2 root root 4096 Feb 6 00:19 install
-rw-r--r-- 1 root root 42129 Aug 23 21:20 install.log
-rw-r--r-- 1 root root 5259 Aug 23 21:20 install.log.syslog
drwxr-xr-x 3 root root 4096 Feb 6 00:19 log
-rwxr-x--- 1 root root 696 Jan 26 14:07 root.sh.racnode1.AFTER_INSTALL