zipl environment file syntax

7.1 LPAR mode z/VM guest KVM guest

The zipl environment file defines the initial mapping between keywords and values established at boot record installation time.

The default location of the file is /etc/ziplenv. To use a file at a different location, use the zipl command option --environment.

Each line of this file defines the mapping on a single keyword-value pair. On each line, the keyword is the sequence of characters that precedes the first equal sign (=). The sequence of characters after that first equal sign (excluding the new-line character) is identified as the value. Values can be empty, but keywords must consist of at least of one character.

The maximum number of keyword-value pairs for one boot partition is 512.

You can modify a zipl environment file with any text editor. An example file might look as follows:

...
ROOT=/dev/dasda1
CRASH=256M
PANIC_TIMEOUT=panic=8
PANIC_TIMEOUT=panic=9
RESERVED=
...

The keywords must satisfy the following requirements:

Consist of at least one character of uppercase letters A - Z, digits 0 - 9, and the _ (underscore).
Must not begin with a digit.

Lines beginning with # are ignored, as are lines without a keyword.

If lines contain identical keywords, the last line overrides preceding ones. For example, in the example file from before, of the two entries for PANIC_TIMEOUT, the entry PANIC_TIMEOUT=panic=9 would be used.

Creating a boot record with a missing, or empty, zipl environment file results in an empty zipl environment block in the boot data. At boot time, all variables that cannot be resolved are removed from the command line.

If the zipl environment file defines more than 512 keyword-value pairs, or if the environment defined by that file exceeds one file-system block, zipl fails to import the file.