Oracle 11g RAC Provisioning Pack tips
Oracle11g Tips by Burleson Consulting
These are work in
progress excerpts from
the book "Oracle
11g New Features" authored by John Garmany, with Oracle ACE's Steve
Karam, Lutz Hartmann, V.J. Jain and Brian Carr.
Oracle RAC is the Cadillac of high-availability utilities, and
Oracle 11g has now made it easier to implement a robust Grid
A pragmatic approach to Oracle scalability
While RAC is the obvious choice for
high availability, many Oracle professionals misunderstand the best
way to plan for fast scalability. These tips on
Oracle scalability note that savvy Oracle shops start with a
"scale up" approach, adding computing resources within a large
monolithic server, and only using Oracle Grid computing (scale out,
a.k.a. horizontal scaling) only after a single server has been
In general, the following are
competing approaches to scaling:
Scale Up (vertical scaling)
Oracle hardware vendors promise
on-demand computing resources, lower TCO, and easy scalability.
Their huge servers offer savings from CPU and RAM consolidation, far
less human management costs, and seamless allocation of resources.
In the "scale
up" approach, server resources (CPU, RAM, Disk) can be added into a
single, monolithic server. Examples include the HP Superdome (64
CPU), the Unisys ES7000 (32 Processors), the Sun Microsystems
SunFire and the IBM X Series. The "scale up" approach has
several benefits over horizontal scaling for Oracle databases:
RAC is not required
Machine resources (especially CPU)
are instantly available for sharing
A single-server requires less
overhead and management
Scale Out (horizontal scaling)
Grid vendors offer solutions where
server blades can be added to Oracle as processing demand increases.
While Grid computing offers infinite scalability, no central point
of failure, and the use of fast cheap server blades, it does have
the same in-the-box parallelism that is found within a monolithic
server. Unlike the scale up approach, Oracle10g Grid computing is
not automatic and requires additional costs, additional training, as
well as sophisticated monitoring and management software.
The "scale out"
approach is designed for super large Oracle databases that support
many thousands of concurrent users. Unless the system has a need to
support more than 10,000 transactions per second, it is likely that
the system will benefit more from a scale up approach.
In the real world, savvy
corporations combine vertical scalability and horizontal
scalability. They start with a large vertical architecture server,
adding resources as-needed. If continuous availability is also
required, they may have a mirrored server using long-distance RAC or
When the single server is approaching capacity, they the "scale out"
with the horizontal scalability, employing RAC and adding additional
servers, each with a vertical scaling architecture.
For these huge shops that rely on
on-demand server allocation with Oracle Grid control we see the
ability to gen-in new servers on an as-needed basis. They keep
a server farm of ready-to-go servers:
In problem is that a new Grid
server must have the software pre-installed before it can be
genned-into a RAC cluster or Oracle application server cluster.
Running the Oracle installer is tedious and time-consuming, and
Oracle has solved this issue by allowing for instant provisioning of
Inside 11g Grid provisioning
The Oracle grid control
provisioning pack allows you to "blow-out" a RAC node without the
time-consuming install, using a pre-installed "footprint". Prior to
11g, the DBA could simply install a binary footprint for the
software (which is tar'ed to the server blade), without a cumbersome
install process. The pre-configured footprint is link edited
and ready to go, making it easy to deploy new Grid servers.
This paper titled
Provisioning RAC and AS using OEM, we see that RAC provisioning
has several sub-components:
"Behind the scenes, provisioning a RAC system
is a combination of the following technologies:
Cloning of ORACLE_HOME
Cloning of a single instance database
Converting a single instance database to RAC".
Bare Metal and Gold provisioning
for Oracle RAC
We see several new terms in the
Oracle 11g documentation referring to "gold" and "bare metal"
provisioning. In Oracle jargon, all ?gold images? are
pre-installed, tested and approved software images that can be
patched to any level before deployment. We see that "gold
images" are a play on words from Linux "bare metal" provisioning:
"On Linux machines the operating system and
the agent software can also be deployed using the Bare Metal
provisioning process introduced in 10gR2. The Bare Metal
provisioning process makes use of the PXE technology to boot
a?kickstart image? of the operating system."
This RAC provisioning features
started within OEM in 10gr3, and it allows a Grid DBA to add a new
RAC node with a single mouse click. Oracle notes that you can
provision a new node with just a mouse click, but only after the
procedure has been set-up:
"All the complexities of provisioning and
configuring the agent, Clusterware, storage, network and the
database software are automated and hidden from the end user.
One can retire the node entirely or relocate the node with a
similar single click effort."
Oracle 11g clusterware deployment guide notes that only a few
steps are required to provision a new server:
0 - Specify the kernel parameters.
1 - Configure block devices for Oracle Clusterware devices.
2 - Ensure you have set the block device permissions correctly.
3 - Use short, nondomain-qualified names for all names in the
4 - Test whether or not the interconnect interfaces are
reachable using the ping command.
5 - Verify that the VIP addresses are not active at the start of
the cloning process by using the ping command (the ping command
of the VIP address must fail).
6 - Run the Cluster Verification Utility (CVU) to verify your
hardware and operating system environment.
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