Database Reference
In-Depth Information
Automated installation
So far the installation described has been manual. This causes two problems: it is not reliably repeatable and it
requires an administrator to sit through it. Surely the administrator can think of more exciting tasks as well. These
disadvantages make the manual approach infeasible, especially when a larger number of servers have to be installed.
Luckily there are alternatives to this labor-intensive process.
Taking a step back and providing a simplified view of the installation process results in the following steps:
1.
Loading the boot loader
2.
Fetching the kernel and initial RAM disk
3.
Starting the installation process
The boot loader is normally installed in the master boot record of the operating system “disk,” from where it picks
a kernel and initial RAM disk. On a system that is yet to be installed this is obviously not the case and the boot loader
will either be on the installation media or provided via the network using the Preboot Execution Environment (PXE).
After the kernel has been loaded, control is transferred to the installer from where it is no different than the manual
installation.
Additional boot arguments can be passed on the boot loader command line instructing the installer to
perform an automated installation. These parameters indicate the location of the Kickstart file and the source of the
installation media. Let's begin by examining how the kernel and initial RAM disk can be obtained via the network.
■
The examples shown below have been created with the security enhanced Linux (seLinux) subsystem set to
“permissive” mode using Oracle Linux 6. If seLinux is set to “enforcing” additional work is necessary to allow the
network services (apache/tftpd) to start and serve the files.
Note
Preparing for PXE booting
Booting into the Preboot Execution Environment and then using Kickstart to install the Linux system to match the
Unix and Oracle standards is the ultimate form of database server build sophistication. The whole task can be a little
bit tricky if a large number of different hardware platforms are used. This is why I suggested standardizing hardware
offerings into three different classes matching processing needs in Chapter 1. This allows the engineering team to
develop a stable set of installation images.
Before it is possible to spawn new servers or virtual machines using PXE-boot and network installations a little
setup work is needed:
1.
The Oracle Linux installation files must be made available over the network.
2.
A TFTP (“trivial FTP”) server must be available to provide a boot environment.
3.
A DHCP (“Dynamic Host Configuration Protocol”) server must be configured.
Normally you would combine the above points on one server. If provisioning of new Oracle Linux instances-
physical or virtual-is a critical task, consider setting up multiple installation servers in your network segment. RSYNC
or similar utilities could be used to keep the installation servers in sync.
Search WWH ::
Custom Search