Booting as a z/VM guest from a SCSI device in secure or non-secure mode

7.1 z/VM guest

Boot Linux™ by issuing the IPL command with an FCP channel as the IPL device. You must specify the target port and LUN for the boot device in advance by setting the z/VM® CP LOADDEV parameter.

Before you begin

You need a SCSI boot device that is prepared with zipl. For more information about SCSI boot devices, see Table 1.

Procedure

Perform these steps to start the boot process:

Establish a CMS or CP session with the z/VM guest virtual machine where you want to boot Linux.
Ensure that the FCP channel that provides access to the SCSI boot disk is accessible to your z/VM guest virtual machine.
Specify the target port and LUN of the SCSI boot disk, and optionally whether to boot in secure boot mode.
Enter a command of this form:
```
#cp set loaddev portname <wwpn> lun <lun> secure
```
where:

<wwpn>

specifies the world wide port name (WWPN) of the target port in hexadecimal format. A blank separates the first eight digits from the final eight digits.

<lun>

specifies the LUN of the SCSI boot disk in hexadecimal format. A blank separating the first eight digits from the final eight digits.

secure

specifies secure boot, see Secure boot. The default is non-secure boot. Secure boot from a SCSI disk under z/VM is supported as of z/VM 7.3.
To specify a WWPN 0x5005076300c20b8e and a LUN 0x5241000000000000 and boot in non-secure mode:
```
#cp set loaddev portname 50050763 00c20b8e lun 52410000 00000000
```
Optional for menu configurations: Specify the boot configuration (boot program in z/VM terminology) to be used. Enter a command of this form:
```
#cp set loaddev bootprog <n>
```
where <n> specifies the configuration number of the boot configuration. Omitting the bootprog parameter or specifying the value 0 selects the default configuration.
Example: To select a configuration with configuration number 2 from a menu configuration:
```
#cp set loaddev bootprog 2
```
Optional: Specify kernel parameters.
```
#cp set loaddev scpdata <APPEND|NEW> '<kernel_parameters>'
```
where:

<kernel_parameters>

specifies a set of kernel parameters to be stored as system control program data (SCPDATA). When booting Linux, these kernel parameters are concatenated to the end of the existing kernel parameters that are used by your boot configuration. The combined parameter string must not exceed a length that is set when the kernel is compiled.
<kernel_parameters> must contain ASCII characters only. If characters other than ASCII characters are present, the boot process ignores the SCPDATA.

<kernel_parameters> as entered from a CMS or CP session is interpreted as lowercase on Linux. If you require uppercase characters in the kernel parameters, run the SET LOADDEV command from a REXX script instead. In the REXX script, use the address command statement. See z/VM: REXX/VM Reference, SC24-6314 and z/VM: REXX/VM User's Guide, SC24-6315 for details.

Optional: APPEND

appends kernel parameters to existing SCPDATA. This is the default.

Optional: NEW

replaces existing SCPDATA.
Examples:
- To append kernel parameter novx to the current SCPDATA:
```
#cp set loaddev scpdata 'novx'
```
- To replace the current SCPDATA with the kernel parameter novx:
```
#cp set loaddev scpdata NEW 'novx'
```
  For a subsequent IPL command, this kernel parameter is concatenated to the end of the existing kernel parameters in your boot configuration.
Start the IPL and boot process by entering a command of this form:
```
#cp i <devno>
```
where <devno> is the device number of the FCP channel that provides access to the SCSI boot disk.
For information about IPL progress messages that are issued before the Linux kernel gets control, see Small Computer Systems Interface (SCSI) IPL Machine Loader Messages, SC28-7006.

Tip

You can specify the target port and LUN of the SCSI boot disk, a boot configuration, and SCPDATA all with a single SET LOADDEV command. See z/VM: CP Commands and Utilities Reference, SC24-6268 for more information about the SET LOADDEV command.