The IBM label partitioning scheme

Red Hat Enterprise Linux 9.2 LPAR mode z/VM guest KVM guest

Linux® on IBM® Z supports the same standard DASD format that is also used by traditional mainframe operating systems, but it also supports any other Linux partition table.

The DASD device driver is embedded into the Linux generic support for partitioned disks. As a result, you can use any partition table format that is supported by Linux for your DASDs.

Traditional mainframe operating systems (such as, z/OS®, z/VM®, and z/VSE®) expect a standard DASD format. In particular, the format of the first two tracks of a DASD is defined by this standard. These tracks include the IBM Z IPL, label, and for some layouts VTOC records. Partitioning schemes for platforms other than IBM Z generally do not preserve these mainframe specific records.

Red Hat® Enterprise Linux 9.2 for IBM Z includes the IBM label partitioning scheme that preserves the IBM Z IPL, label, and VTOC records. With this partitioning scheme, Linux can share a disk with other mainframe operating systems. For example, a traditional mainframe operating system can handle backup and restore for a partition that is used by Linux.

The IBM label partitioning scheme supports the compatible disk layout (CDL), the Linux disk layout (LDL), and the CMS disk layout (CDL).