There is only one additional requirement this
time around - you need your host to provide two network cards to
virtual machine: one for the Oracle public network and one for the
Oracle private network, i.e. the RAC interconnect. Hence, you need
to end up with your host configured as shown in Figure 2 (next
page). Do not be confused by the terminology here. The VMware
network settings are both Host-only, which simply means that
they cannot see the outside world. But they can see everything
within that host including both the Oracle public and private
networks. If you wanted this setup to be available to other PCs,
then the first network setting, VMnet1, would need to be opened up.
Figure 2: Host
Configuration Screen
Note that the only difference between VMnet1 and
VMnet2 are the assigned IP addresses. I?m allocating the
192.168.100.xxx range for my Oracle public network, and
192.168.200.xxx range for my Oracle private network. My hosts file
changes as follows (new entries in bold):
# Laptop/Notebook Demo
HOSTS file
#
127.0.0.1 localhost
192.168.100.101 linux
192.168.100.102 linux_10g
192.168.100.103 linux_11g
192.168.100.104 linux_rac
192.168.200.104 linux_rac-priv
192.168.100.105 linux_rac-vip
Note that last new entry above for the Oracle
virtual IP address, which is not represented in your VMware host
network settings. Oracle will create a special network adapter
itself on the VMware client operating system to handle load
balancing and fault tolerance (this step is discussed and shown
later in this chapter). Since your entire RAC cluster is really all
on one node, you could just use the linux_rac alias. But in
your efforts to attempt to keep this setup as realistic as possible,
you should use the virtual IP address of linux_rac-vip just
like any other normal RAC configuration.
Virtual Machine Setup
You need to make two key modifications to the
virtual machine setup as shown in Figure 3 (following page). Both
changes are very easy and should take only a moment to complete.
These changes can be easily made to an existing VMware image in case
you are reusing a pre-existing VMware golden image .
Figure 3:
Virtual Machine Setup Modifications
First, you need to add a second hard disk device
to host your shared file system for the RAC cluster. Note above that
I have added Hard Disk 2 and allocated 10 GB to it. That is going to
house the Oracle Cluster File System, or ocfs2. You have numerous
other options not covered here:
-
Allocate the second disk, but use Oracle ASM to
manage the shared storage device (note that ASM will be used in
the next chapter when doing a true multi-node RAC setup)
-
Not allocate second disk, use Linux loop back
devices to create the ocfs2 file system within the existing ext3
Linux file system
-
Not allocate second disk, use Linux loop back
devices to create raw devices to then allocate to ASM to manage as
if real disks
-
Allocate the second disk, but use a Linux
clustered file system such as Open GFS, Red Hat GFS, Veritas
Storage Foundation CFS, Poly Serve Matrix Server , IBM General
Parallel File System, SGI XFS for Linux, HP Storage Works Scalable
File Share, Sun Lustre File System, Sun SAM-QFS, etc.
-
Allocate the second disk, but use VMware VMFS - a high performance cluster file system optimized for virtual
machines
Of those choices, the first three alternatives
could easily be used instead of the choice to allocate a second
drive and use Oracle's ocfs2. And for simple demo, experimentation
or playground type purposes, any of them will suffice without undo
expense or difficulty. However, for testing and production purposes,
only the first and final two choices make sense. Since ASM is free,
readily supported (and preferred) for RAC setups, and being used by
over 60% of new RAC deployments, it makes a good enough choice for
our purposes.
Next, you need to add a second Ethernet network
card based off VMnet2, which was defined in the prior step. This
will be used by the RAC instances as the Oracle private network or
interconnect. There are two important reasons for doing this. First,
doing so most closely approximates a true RAC environment. Secondly,
the RAC interconnect is often the bottleneck in overall maximum
performance. So having it on a separate network provides better
ability to monitor and diagnose such RAC interconnect issues if they
occur.
This is an excerpt from
Oracle on VMWare:
Expert tips for database virtualization
by Rampant TechPress.
