VMware: Client Operating System

Again, I do not want to start any heated debates or religious wars, but for simple demo purposes, Linux makes a very good OS choice. It is free, Oracle is primarily developed there (so new releases and patches come earlier) and it just feels somewhat more realistic to have Windows based applications talking to non-Windows based databases (which is similar to many historically popular Oracle deployment scenarios). While Redhat and SuSE are both popular Oracle Linux platforms, there are some nice free alternatives: CentOS and Oracles Enterprise Linux. Both are essentially compatible with Redhat and so easy to use with plenty of good reference materials that apply. In this book, I will use CentOS. That is not a reflection of any superiority of that Linux distribution, it's just that it is close enough to Redhat and I am both very comfortable with and accustomed to it.

To initiate the OS installation process, simply place the Linux DVD in your laptops/notebooks DVD drive and tell VMware to start that virtual machine. The process is now essentially 100% the same as if being done on a standalone machine. We will review some very important Oracle optimizations to make during the Linux installation process and also afterwards.

When asked which type of install to perform, it is generally better to choose a custom Linux install so that you can specifically pick only those items that you know your database setup will need. Also choose to manually define your partitions. Then, when the Disk Setup screen comes up, choose setup values such as those shown here in Figure 11 on the next page. The /boot area is where the kernel images are kept to boot the machine. The swap area is kept to a minimum (i.e. 1 GB or swap = RAM), since you are aiming for a very minimal database setup on a limited laptop/notebook for basic demo purposes.

Figure 11:   Custom Setup Values

When the Network Configuration screen comes up, you need to define your network as shown in Figure 12 (next page). Keep in mind that you are choosing to create a static IP address for a private network, i.e. a VMware host-only connection to the network. Also remember that by using consistent alias names whenever possible throughout the client operating system install process, you will be able to reproduce this 11g setup quite easily anytime.

Figure 12:  Network Configuration Definitions

When the Firewall Configuration screen comes up, you need to not enable the client operating systems firewall or Security Enhanced (SE) Linux security options as shown in Figure 13. The reason for this is very simple you are creating a private network, so there will be little or no need for firewall protection. Besides, database server based firewalls just add one additional level of complexity for configuring Oracle because the Oracle listener watches port 1521 by default, which would require you opening the port so that database traffic flows unimpeded. Therefore, it is easier to not install the firewall and thus avoid that step. Furthermore, you will avoid additional overhead on your client operating system, which was defined as a critical issue in keeping this system minimal since you want to be able to run Oracle 11g on a laptop/notebook for doing demos.

Figure 13:  Custom Firewall Configuration

When the Package Selection screen comes up (shown on the next page in Figure 14), take your time and choose just those software packages that you know that you will want to be able to use while keeping your selections to a minimum wherever possible. There are two reasons for this. First, as mentioned before in creating a minimal system, you want to keep the overhead to a minimum. The more software you choose, the more services, demons or processes that may need to run. And second, you defined your virtual machine using dynamic disk space allocation (i.e. it grows). So the more you choose to install, the larger your virtual machines file on the host will become. While that can slow performance a wee bit, it is the zipping and unzipping delays that quickly become the real issue. The smaller you keep the client, the smaller and faster working with the zip files will be. That can be critical for when you want to do quick rebuilds.

Figure 14:  Software Package Selection

So what do I recommend as some minimal choices? Well, as much as I would like to skip X-Windows (i.e. boot in terminal mode), you do need the X-Windows environment to run the Oracle installer, which is a Java based GUI (Graphical User Interface) product. So the first two choices for X-Windows and the Gnome Desktop are the bare minimums. From there, it all depends on how you like to work. Some people like to include an FTP server so that they can transfer files over to the client (e.g. the Oracle install image). And while that is a relatively easy and straightforward process, nonetheless, it is very inefficient because you are storing the same data twice on your laptops/notebooks limited disk space. Thus, it is often wise to install the Windows File Server, i.e. Samba. We will go with Samba for now and later we will set it up so that it can see the hosts file system.

Towards the very end of the install process, the Linux installer will present what it thinks the default Display characteristics are (shown below in Figure 15). This is a very easy screen to ignore and rush through. But there are some real performance and usability implications here, so you should make some wiser choices.

Figure 15:  Display Characteristics Screen

The default display type most often comes up as 800x600. And while that is an efficient setting, with today's higher display resolution capabilities, 1024x768 is a reasonable choice that balances efficiency with usability. As for the color depth, thousands of colors will more than suffice. You do not need millions of colors, especially if you don't plan to do much via the GUI on the client other than to run the Oracle installer and occasionally show that you are running Linux under the covers. Besides, it is quite possible that you have already made the exact same concession on your Windows display settings. You can't really tell Windows to restrict it's color palette and then turn around and tell one of it's applications (i.e. VMware) to use more than the operating system permits. The display characteristics discussion also nicely segues into the next topic.

This is an excerpt from Oracle on VMWare: Expert tips for database virtualization by Rampant TechPress.