VMware ESX, NIC Teaming, and VLAN Trunking with HP ProCurve

VMware ESX, NIC Teaming, and VLAN Trunking with HP ProCurve

In an earlier article about VMware ESX, NIC teaming, and VLAN trunking, I described what the configuration should look like if one were using these features with Cisco switch hardware. It’s been a quite popular post, one I will probably need to update soon.

Changing Linux IP Emphermel Port Ranges

Linux allows you to view and change the ephemeral port range by simply using the file /proc/sys/net/ipv4/ip_local_port_range.  For example, this shows the default configuration on a kernel 2.2 system:

$ cat /proc/sys/net/ipv4/ip_local_port_range 
1024 4999

To change this to the preferred range, you could do (as superuser):

Adding Permission to your Java home directory

Adding Permissions to Java in your home directory.

<applet codebase="../jar/" ....

Your .java.policy file in your home directory would have an entry looking something like this:-

grant codeBase "file:///Users/ben/path-to-project/build/Debug/project-name.jar" {
permission java.security.AllPermission;

keytool -importcert -keystore "...\java\ jdk1.6.0_17\jre\lib\security\cacerts" -storepass changeit -alias agrozoocert2011dsa -file agrozoocert2011dsa.cer

Tar and Gzip Useful Commands

Usefull Tar and Gzip Commands:


tar c <directoryto.tgz> | gzip > <tarname>.tar.gz

Upgrading a Netgear WG602v3 using Cygwin and TFTP with DD-WRT micro Firmware

1)) Factory reset the WG602, and connect your PC to it via a LAN cable

2) Give your PC's LAN NIC a static IP Address of

3) Fireup a cygwin shell of your choice and make sure you have run the cygwin setup and install tftp client/server under the Net category.

Hadoop Cluster - Bookmarks and help URLs

1.5. I have a new node I want to add to a running Hadoop cluster; how do I start services on just one node?

This also applies to the case where a machine has crashed and rebooted, etc, and you need to get it to rejoin the cluster. You do not need to shutdown and/or restart the entire cluster in this case.

First, add the new node's DNS name to the conf/slaves file on the master node.

Fine tuning Apache Hadoop Security Settings

Apache Hadoop is equipped with a robust and scalable security infrastructure. These notes are intended to cluster administrators fine-tune the security settings of their clusters.

Quality of Protection:

Security infrastructure for Hadoop RPC uses Java SASL APIs. Quality of Protection (QOP) settings can be used to enable encryption for Hadoop RPC protocols.

Java SASL provides following QOP settings:

Best Practices Selecting Hadoop Hardware

Excerpts of this article are copyright there respective owners: The original article can be found at : Hortonworks

Apache Hadoop worker node hardware @ Yahoo!, a lot of nodes with 6*2TB SATA drives, 24GB RAM and 8 cores in a dual socket configuration. This has proven to be a pretty good configuration. This year, I’ve seen systems with 12*2TB SATA drives, 48GB RAM and 8 cores in a dual socket configurations. We will see a move to 3TB drives this year.

Setting up Apache Hadoop on RHEL6/CentOS 6

Setting up Apache Hadoop on RHEL6/CentOS 6 is simple wiith the recent availability of RPMs for Apache Hadoop it makes it much simpler to setup a basic Hadoop cluster. This will allow you to focus on how to use the features instead of having to learn how they were implemented.

These instructions DO NOT Hadoop settings to make Hadoop fast but it will get you running a Hadoop culster fast. We will leave Hadoop optimization for another day.

Installing Java JRE and JDK version 1.7(1.6) on CentOS 6 and config the system alternatives for "java"

You should simply use the packages from Sun.

Step (1) : Visit Sun’s web site and download the latest version of Java (the *.bin file not the *-rpm.bin) (http://java.sun.com/javase/downloads/index.jsp)

(pay close attention if you want the 32bit or 64bit version)

Example the 64-bit version of the JDK can be found at http://download.oracle.com/otn-pub/java/jdk/7/jdk-7-linux-x64.rpm


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