Acquiring the Required Hardware

Oracle Database Tips by Donald Burleson

The goal of this book is to assemble a functioning Oracle Real Application Cluster database on hardware that can be purchased easily and inexpensively.

Figure 1.1 shows the hardware configuration of a two node RAC. Each node has two network interface cards and one firewire card. The crossover cable is an internal network that supports Oracle's cache fusion. This internal network allows the nodes to communicate very quickly, which is necessary to keep the buffer cache of each node in synch with the buffer cache of the other.

If a third node is needed, a network hub for the internal network and a firewire hub for the external disk drive will be required as shown in Figure 1.2. Notice that the cross-over cable is replaced by standard network cables.

The following table examines the items needed to build a two node Oracle RAC, and includes estimates for what it will cost to purchase each item:

ITEM	ESTIMATED COST	AUTHOR's NOTES
Two nodes	$400.00 for both.	The nodes should be Pentium 3's or higher. For this book, two used Dell Dimension 4100 Computers were purchased on ebay.com for $200 each. Each computer included one hard drive with a capacity of 10 to 20 gigabytes and at least 256 Megabytes of ram.
Four Network Interface Cards	$20 to $50 for all four.	Refurbished NIC cards are generally available at Fry's electronics for $5 each.
Two 1394 Firewire cards	$40 to $70 for both.	The firewire cards were purchased for $20 each at CompUSA.
One Crossover Cable - 3ft.	$5	If a crossover cable cannot be found, a hub and two standard network cables will work in its place.
Two Network Cables - 15ft	$15
One Extra Firewire Cable	$10
Additional CD Roms	$50	Each node will require a CD Rom device; one with the ability to burn CDs.
Additional RAM	$100	Each node will require no less than 512 megabytes of RAM. A 9i RAC database can be built with less RAM installed in each node, but creating 10g databases with less than 512 megabytes will most likely fail.
One Monitor	$0 to $100	A 15 inch monitor will work just fine, though a 17 inch monitor is ideal.
One Keyboard and Mouse	$0 to $30
One 2-port KVM switch	$50	A Belkin model with built in cabling was purchased. To switch between the two nodes, the user types {scroll lock} {scroll lock} {up-arrow}.
One wired network router	$30
One power strip	$5
One External Hard Drive	$225	The Maxtor model A01A200 was used for this book. This hard disk allows for dual logging which is required. LaCie also makes external drives that work. When in doubt, get the Maxtor model. Do not buy any brand of hard disk just because it is firewire. Most likely it will not allow for dual logging and will fail.
Two additional internal hard drives	$50 for both	Appendix C of this book covers how to take an image copy of the operating system to be able to restore to a previous point. The ideal method is to use an extra hard disk of 3 to 10 gigabytes in each node.
One Client Computer with networking support.	$0	It is assumed that an additional windows computer is available. This is required to burn CDs and will be used as a client of the database.
Broadband internet service	$30 per month
Blank CDs	$10	At least 10 blank CDs are required.
One Card table, 2? x 4?	$30

Table 1.1: Items needed to build a two node Oracle RAC

Before purchasing anything, it is a good idea to ask family, friends and neighbors for computer parts that are no longer in use. Many of the items in this list can be found collecting dust in someone's garage or basement. Most people are more than happy to get rid of such ?junk.?

Try to obtain two internal hard drives for each node. The first hard drive of a given node will need a capacity of at least 10 gigabytes. It will be used to store the operating system and the Oracle software. The second hard drive for a node should have a capacity of three or more gigabytes. It will be used to store a compressed image of the first drive. An image of the primary hard drive will allow you to quickly revert to a pervious point in the project, without having to reinstall and reconfigure from the very beginning.

Below are a few tips for assembling the hardware:

Put all the hardware together before installing the operating systems or software.
If working with used computers, purchase a can of compressed air to safely blow away the accumulated dust.
When putting the hardware together, avoid working in a room with carpeting. Carpeting generates static electricity and static electricity can ruin electronics. If this cannot be avoided, keep yourself grounded with a grounding strap as you assemble the hardware. Never place a network card, firewire card, RAM board or other unprotected electronic devices directly on a carpeted surface.
When a NIC card or other device is pushed into a slot on the motherboard so that it seats properly (resting flush at the bottom of the slot), sometimes the bracket will not align with the screw-hole on the case. Do not force the card out of its alignment to make the bracket conform to the screw-hole. It is better to take the card out, bend the bracket to fit and then reinsert the card.
Install the internal hard disks so that they share one IDE cable. Doing so will make it possible for the CD ROM drive to be on a separate cable. If the CD ROM must be on the same cable as a hard disk, ensure that the hard disk is the master and that the CD ROM is the slave.
When two devices share the same IDE cable, one device must be set as the master and one must be set as the slave. There are two methods for doing this. The first method is to indicate directly which device is which with the appropriate jumper settings. The second is the cable select method. To use the cable select method, set the jumpers on both devices to the cable select setting. The device at the final end of the cable will be the master and the other will be the slave.
Many hard drives have a diagram on the outside showing the jumper settings for master, slave, and cable select. Some older drives do not. To find the jumper settings for any drive, use a search engine to search for the drive model number and the words ?jumper master slave.?
Remove any unnecessary cards that may be plugged into the mother board such as sound cards or SCSI cards.
Once all of the internal hardware is connected, turn on the computer and enter the BIOS setup. Common methods for entering setup are pressing the delete key, the F1 key or the F2 key before the system boots from disk. Upon entering setup, double check that the system detects the internal hard disks, the RAM, the CD ROM and the floppy drive if applicable. Verify that the system boots from the CD ROM before it boots from the hard disk.
When the internal hardware is completely installed and the covers of the nodes are closed, connect the firewire drive to the firewire ports of each node and then turn the drive on.