The Oracle 11gR2 Grid installer includes a useful verify utility called runcluvfy.sh.  This script is found in the grid directory, the same directory where you find runInstaller

The following shows the output of running runcluvfy.sh against a VMWare based RAC.

Resolve problems detected by this script before running the runInstaller script.

[oracle@orpheus grid]$ ./runcluvfy.sh stage -pre crsinst -n orpheus,eurydice

Performing pre-checks for cluster services setup 

Checking node reachability...
Node reachability check passed from node "orpheus"

Checking user equivalence...
User equivalence check passed for user "oracle"

Checking node connectivity...

Checking hosts config file...

Verification of the hosts config file successful

Node connectivity passed for subnet "192.168.0.0" with node(s) orpheus,eurydice
TCP connectivity check passed for subnet "192.168.0.0"

Node connectivity passed for subnet "10.10.1.0" with node(s) orpheus,eurydice
TCP connectivity check passed for subnet "10.10.1.0"

Node connectivity passed for subnet "10.10.2.0" with node(s) orpheus,eurydice
TCP connectivity check passed for subnet "10.10.2.0"

Interfaces found on subnet "192.168.0.0" that are likely candidates for VIP are:
orpheus eth0:192.168.0.19
eurydice eth0:192.168.0.18

Interfaces found on subnet "10.10.1.0" that are likely candidates for a private interconnect are:
orpheus eth1:10.10.1.10
eurydice eth1:10.10.1.20

Interfaces found on subnet "10.10.2.0" that are likely candidates for a private interconnect are:
orpheus eth2:10.10.2.10
eurydice eth2:10.10.2.20

Node connectivity check passed

Total memory check passed
Available memory check passed
Swap space check passed
Free disk space check passed for "orpheus:/tmp"
Free disk space check passed for "eurydice:/tmp"
User existence check passed for "oracle"
Group existence check passed for "oinstall"
Group existence check passed for "dba"
Membership check for user "oracle" in group "oinstall" [as Primary] passed
Membership check for user "oracle" in group "dba" passed
Run level check passed
Hard limits check passed for "maximum open file descriptors"
Soft limits check passed for "maximum open file descriptors"
Hard limits check passed for "maximum user processes"
Soft limits check passed for "maximum user processes"
System architecture check passed
Kernel version check passed
Kernel parameter check passed for "semmsl"
Kernel parameter check passed for "semmns"
Kernel parameter check passed for "semopm"
Kernel parameter check passed for "semmni"
Kernel parameter check passed for "shmmax"
Kernel parameter check passed for "shmmni"
Kernel parameter check passed for "shmall"
Kernel parameter check passed for "file-max"
Kernel parameter check passed for "ip_local_port_range"
Kernel parameter check passed for "rmem_default"
Kernel parameter check passed for "rmem_max"
Kernel parameter check passed for "wmem_default"
Kernel parameter check passed for "wmem_max"
Kernel parameter check passed for "aio-max-nr"
Package existence check passed for "make-3.81"
Package existence check passed for "binutils-2.17.50.0.6"
Package existence check passed for "gcc-4.1"
Package existence check passed for "libaio-0.3.106 (i386)"
Package existence check passed for "libaio-0.3.106 (x86_64)"
Package existence check passed for "glibc-2.5-24 (i686)"
Package existence check passed for "glibc-2.5-24 (x86_64)"
Package existence check passed for "compat-libstdc++-33-3.2.3 (i386)"
Package existence check passed for "compat-libstdc++-33-3.2.3 (x86_64)"
Package existence check passed for "elfutils-libelf-0.125 (x86_64)"
Package existence check passed for "elfutils-libelf-devel-0.125"
Package existence check passed for "glibc-common-2.5"
Package existence check passed for "glibc-devel-2.5 (i386)"
Package existence check passed for "glibc-devel-2.5 (x86_64)"
Package existence check passed for "glibc-headers-2.5"
Package existence check passed for "gcc-c++-4.1.2"
Package existence check passed for "libaio-devel-0.3.106 (i386)"
Package existence check passed for "libaio-devel-0.3.106 (x86_64)"
Package existence check passed for "libgcc-4.1.2 (i386)"
Package existence check passed for "libgcc-4.1.2 (x86_64)"
Package existence check passed for "libstdc++-4.1.2 (i386)"
Package existence check passed for "libstdc++-4.1.2 (x86_64)"
Package existence check passed for "libstdc++-devel-4.1.2 (x86_64)"
Package existence check passed for "sysstat-7.0.2"
Package existence check passed for "unixODBC-2.2.11 (i386)"
Package existence check passed for "unixODBC-2.2.11 (x86_64)"
Package existence check passed for "unixODBC-devel-2.2.11 (i386)"
Package existence check passed for "unixODBC-devel-2.2.11 (x86_64)"
Package existence check passed for "ksh-20060214"
Check for multiple users with UID value 0 passed 
Current group ID check passed
Core file name pattern consistency check passed.

User "oracle" is not part of "root" group. Check passed
Default user file creation mask check passed

Starting Clock synchronization checks using Network Time Protocol(NTP)...

NTP Configuration file check started...
NTP Configuration file check passed

Checking daemon liveness...
Liveness check passed for "ntpd"

NTP daemon slewing option check passed

NTP daemon's boot time configuration check for slewing option passed

NTP common Time Server Check started...
Check of common NTP Time Server passed

Clock time offset check from NTP Time Server started...
Clock time offset check passed

Clock synchronization check using Network Time Protocol(NTP) passed

Pre-check for cluster services setup was successful. 
[oracle@orpheus grid]$