I have been asked a few times how one can make use of the Oracle VM API to configure an Oracle Linux VM running on top of Oracle VM 3. In the next few blog entries we will go through the various steps. This one will start at the beginning and get you to a completely prepared VM.
You can freely download Oracle Linux installation images from http://edelivery.oracle.com/linux.
dlmfs is a really cool nifty feature as part of OCFS2. Basically, it's a virtual filesystem that allows a user/program to use the DLM through simple filesystem commands/manipulation. Without having to write programs that link with cluster libraries or do complex things, you can literally write a few lines of Python, Java or C code that let you create locks across a number of servers. We use this feature in Oracle VM to coordinate the master server and the locking of VMs across multiple nodes in a cluster. It allows us to make sure that a VM cannot start on multiple servers at once.
A cool, but often missed feature in Oracle Linux is the inclusion of OCFS2. OCFS2 is a native Linux clusterfilesystem which was written many years ago at Oracle (hence the name Oracle Cluster Filesystem) and which got included in the mainline Linux kernel around 2.6.16 somewhere back in 2005. The filesystem is widely used and has a number of really cool features.
A little known feature that we make good use of in Oracle VM is called dm nfs. Basically the ability to create a device mapper device directly on an nfs-based file/filesystem. We use this in Oracle VM 3 if your shared storage for the cluster is nfs based.
Oracle VM clustering relies on the OCFS2 clusterstack/filesystem that is native in the kernel (uek2/2.6.39-x). When we create an HA-enabled pool, we create, what we call, a pool filesystem. That filesystem contains an ocfs2 volume so that we can store cluster-wide data.
In this blog entry I try to document how to enable Kerberos. This procedure was actually created and followed during a project at one of my customers.
– windows 2008R2 server
– domain : milkyway.space.com
– Kerberos installed and enabled
– DES encryption default disabled
– database : crater
– version : 22.214.171.124.4
– windows 7 enterprise edition
– 126.96.36.199 client
I found this needed a blog post because most of the customers I meet, just install their Redhat/Oracle Linux environment and start using it out of the box in production. I believe this list should be included in every post-installation procedure.
Nice article on the oracle website about the internals of OVM by Gregory King and Suzanne Zorn.
I really like these kind of articles.
Check it out : http://www.oracle.com/technetwork/articles/servers-storage-admin/networking-ovm-x86-1873548.html
We just introduced a new yum repository/channel on http://public-yum.oracle.com called the playground channel. What we started doing is the following:
When a new stable mainline kernel is released by Linus or GregKH, we internally build RPMs to test it and do some QA work around it to keep track of what's going on with the latest development kernels. It helps us understand how performance moves up or down and if there are issues, we try to help look into them and of course send that stuff back upstream.