19.2. Preparing for a Hard Drive Installation

Use this option to install Red Hat Enterprise Linux on hardware systems without a DVD drive and if you do not want to access installation phase 3 and the package repository over a network.

19.2.1. Accessing Installation Phase 3 and the Package Repository on a Hard Drive

Note

Hard drive installations using DASD or FCP-attached SCSI storage only work from native ext2, ext3, or ext4 partitions. If you have a file system based on devices other than native ext2, ext3, or ext4 (particularly a file system based on RAID or LVM partitions) you will not be able to use it as a source to perform a hard drive installation.

Hard drive installations use an ISO image of the installation DVD (a file that contains an exact copy of the content of the DVD), and an install.img file extracted from the ISO image. With these files present on a hard drive, you can choose Hard drive as the installation source when you boot the installation program.

Hard drive installations use the following files:

an ISO image of the installation DVD. An ISO image is a file that contains an exact copy of the content of a DVD.
an install.img file extracted from the ISO image.
optionally, a product.img file extracted from the ISO image.

With these files present on a hard drive, you can choose Hard drive as the installation source when you boot the installation program (refer to Section 22.4, “Installation Method”).

Ensure that you have boot media available as described in Chapter 20, Booting (IPL) the Installer.

To prepare a DASD or FCP-attached device as an installation source, follow these steps:

Obtain an ISO image of the Red Hat Enterprise Linux installation DVD (refer to Chapter 1, Obtaining Red Hat Enterprise Linux). Alternatively, if you have the DVD on physical media, you can create an image of it with the following command on a Linux system:
```
dd if=/dev/dvd of=/location/of/disk/space/RHEL6.iso
```
where dvd refers to your DVD drive device.
Transfer the ISO images to the DASD or SCSI device.
The ISO files must be located on a hard drive that is activated in installation phase 1 (refer to Chapter 21, Installation Phase 1: Configuring a Network Device) or in installation phase 2 (refer to Chapter 22, Installation Phase 2: Configuring Language and Installation Source). This is automatically possible with DASDs.
For an FCP LUN, you must either boot (IPL) from the same FCP LUN or use the rescue shell provided by the installation phase 1 menus to manually activate the FCP LUN holding the ISOs as described in Section 25.2.1, “Dynamically activating an FCP LUN”.
Use a SHA256 checksum program to verify that the ISO image that you copied is intact. Many SHA256 checksum programs are available for various operating systems. On a Linux system, run:
```
$ sha256sum name_of_image.iso
```
where name_of_image is the name of the ISO image file. The SHA256 checksum program displays a string of 64 characters called a hash. Compare this hash to the hash displayed for this particular image on the Download Software page on the Red Hat Network (refer to Chapter 1, Obtaining Red Hat Enterprise Linux). The two hashes should be identical.

Copy the images/ directory within the ISO file to a directory named images/. Enter the following commands:

  mount -t iso9660 /path/to/RHEL6.iso /mnt/point -o loop,ro
  cp -pr /mnt/point/images /path/images/
  umount /mnt/point

Verify that the the images/ directory contains at least the install.img file, without which installation cannot proceed. Optionally, the images/ directory should contain the product.img file, without which only the packages for a Minimal installation will be available during the package group selection stage (refer to Section 23.17, “Package Group Selection”).
Make the DASD or SCSI LUN accessible to the new z/VM guest virtual machine or LPAR, and then proceed with installation. (Refer to Chapter 20, Booting (IPL) the Installer) or alternatively with Section 19.2.1.1, “Preparing for Booting the Installer from a Hard Drive”.

Note — Verifying ISO images

The Red Hat Enterprise Linux installation program can test the integrity of the installation medium. It works with the DVD, hard drive ISO, and NFS ISO installation methods. We recommend that you test all installation media before starting the installation process, and before reporting any installation-related bugs. To use this test, add the mediacheck parameter to your parameter file (refer to Section 26.7, “Miscellaneous parameters”).

19.2.1.1. Preparing for Booting the Installer from a Hard Drive

If you would like to boot (IPL) the installer from a hard drive, in addition to accessing installation phase 3 and the package repository, you can optionally install the zipl boot loader on the same (or a different) disk. Be aware that zipl only supports one boot record per disk. If you have multiple partitions on a disk, they all “share” the disk's one boot record.

In the following, assume the hard drive is prepared as described in Section 19.2.1, “Accessing Installation Phase 3 and the Package Repository on a Hard Drive”, mounted under /mnt, and you do not need to preserve an existing boot record.

To prepare a hard drive to boot the installer, install the zipl boot loader on the hard drive by entering the following command:

zipl -V -t /mnt/ -i /mnt/images/kernel.img -r /mnt/images/initrd.img -p /mnt/images/generic.prm

For more details on zipl.conf, refer to the chapter on zipl in Linux on System z Device Drivers, Features, and Commands on Red Hat Enterprise Linux 6.

Warning — Accessing a previously-installed operating system

If you have an operating system installed on the disk, and you still plan to access it later on, refer the chapter on zipl in Linux on System z Device Drivers, Features, and Commands on Red Hat Enterprise Linux 6 for how to add a new entry in the zipl boot loader (that is, in zipl.conf).