RHEL System Configuration Changes for Oracle 10G

Below is a list of RHEL system configuration changes that Oracle 10G requires before it is installed.

First, check the following kernel parameters using the commands below:


/sbin/sysctl -a | grep kernel.shmall
/sbin/sysctl -a | grep kernel.shmmax
/sbin/sysctl -a | grep kernel.shmmni
/sbin/sysctl -a | grep kernel.sem
/sbin/sysctl -a | grep fs.file-max
/sbin/sysctl -a | grep net.ipv4.ip_local_port_range
/sbin/sysctl -a | grep net.core.rmem_default
/sbin/sysctl -a | grep net.core.rmem_max
/sbin/sysctl -a | grep net.core.wmem_default
/sbin/sysctl -a | grep net.core.wmem_max

If any parameters are lower than the examples below, you will have to increase them by editing “/etc/sysctl.conf” file, adding the appropriate lines as expressed below. If the current value is higher, leave it as is.

kernel.shmall = 2097152
kernel.shmmax = 2147483648
kernel.shmmni = 4096
kernel.sem = 250 32000 100 128
fs.file-max = 65536
net.ipv4.ip_local_port_range = 1024 65000
net.core.rmem_default = 262144
net.core.rmem_max = 262144
net.core.wmem_default = 262144
net.core.wmem_max = 262144

Next, edit your “/etc/security/limits.conf” file, adding the following lines:

oracle          soft    nproc           2047
oracle          hard    nproc           16384
oracle          soft    nofile          1024
oracle          hard    nofile          65536

If your current “/etc/pam.d/login” file does not already contain the following line, add it:

session    required     pam_limits.so

Finally, add the following lines to your "/etc/profile" file:

#Tweaks for Oracle
if [ $USER = "oracle" ]; then
    if [ $SHELL = "/bin/ksh" ]; then
    ulimit -p 16384
    ulimit -n 65536
    else
    ulimit -u 16384 -n 65536
    fi
fi

These are just the basic steps I take. See the “Oracle Database Installation Guide” for more complete instructions.

When Mac OSX SMB Connections Fail

Earlier today I had a problem with some Macs that could not establish SMB connections to our Windows File Server. There was no quick error, so the problem really “felt” like a firewall issue but strangely I was able to make a CLI connection to the file server using smbclient:


smbclient //server/share -U domain/username
Password:*******
Domain=[DOMAIN] OS=[Windows Server x] Server=[Windows Server x]
smb: \> exit

I started thinking that perhaps the Mac was doing NETBIOS name lookups and that nmbd might be knocking on the firewall. Turns out this was the problem. Opening up the following ports on the Windows File Server did the trick:

SMB uses ports:
UDP 137 (NETBIOS Name Service)
UDP 138 (NETBIOS Datagram Service)
TCP/UDP 139 (NETBIOS Session Service)

WARNING: Only open these ports to your trusted networks. Statistical data indicates that UDP ports 135 – 139 and TCP port 137 – 139 are amongst the most commonly scanned ports on remote computers.

Girl in Clinton’s “Red Phone” Ad Supports Obama

It turns out that the sleeping little girl in Hillary Clinton’s “Red Phone” TV advertisement is supporting Barack Obama. The Clinton campaign used stock footage of the girl who is now of voting age and calls “Red Phone” ad “Fear Mongering”. I guess the Clinton crew should have thought about that.