Site-specific Linux instantiation

Backup sites usually hold a copy of the boot device with the Linux boot image and, if separate, the device with the root file system and other essential devices. To accommodate diverging conditions between backup sites, Red Hat® Enterprise Linux 9.2 supports site-specific instantiation for up to 10 different sites. A site is identified through an integer in the range 0 to 9.

Site-specific kernel parameters

The zipl environment includes site-specific sections that capture site-specific variations of the kernel parameters. For more information about site-specific kernel parameters, see Site-aware zipl environment.

Site-specific DASD configuration

With the --site option of the chzdev command, you can create persistent DASD configurations that apply only to a specific site. For more information about site-specific DASD configurations, see Configuration scope.

You use the site ID as part of the load parameter when you IPL the boot device on a particular site. Use the S keyword to specify a site. Site-specific values extend and override common specifications for the kernel parameters and device configurations, which apply if no particular site is specified.

S<n>

Specifies site <n>. If no site-specific kernel parameters or DASD configurations are available for the specified site, common specifications apply.

SS

Uses the subchannel set ID (SSID) of the IPL device as the site ID, for example, if the SSID is 0, values for site 0 are used.

S

Uses the common specifications. Specifying a single capital S without a trailing site ID is equivalent to omitting the S parameter.

If you need the load parameter to also select an entry from a menu configuration, append the site selection to the menu selection without a blank. Append any other load parameter values to the site selection.