Control point and boot medium
The control point from where you can start the IPL depends on your hypervisor environment.
- LPAR
- For Linux® in LPAR mode, the control point is the mainframe's Support Element (SE) or an attached Hardware Management Console (HMC).
- z/VM®
- For Linux on z/VM, the control point is the control program (CP) of the hosting z/VM system.
- KVM
- For Linux on KVM, the control point is the KVM host.
The media that can be used as boot devices also depends on the hypervisor. Table 1 provides an overview of the possibilities:
| Medium | LPAR | z/VM guest | KVM guest |
|---|---|---|---|
| DASD | ✓ | ✓ | ✓ |
| SCSI | ✓ | ✓ | |
| CD-ROM/DVD/FTP | ✓ | ||
| z/VM reader | ✓ | ||
| virtio block device | ✓ | ||
| virtio SCSI device | ✓ |
In the table:
- As of z14, a SCSI boot device is an FC-attached disk. Support for an FC-attached CD-ROM or DVD drive as a boot device is available on IBM Z® hardware prior to z14.
- CD-ROM/DVD/FTP can be the CD-ROM or DVD drive of the SE or HMC, or it can be a remote FTP server.
- A virtio block device can be backed by an ISO image in the KVM host file system or by any IPL device that was prepared with GRUB 2.
Typically, booting from removable media applies to initial installation of Linux. Booting from DASD or SCSI disk devices usually applies to previously installed Linux instances.