If you need a DCSS that is defined with special options,
you must use a workaround to save the DCSSs.
Before you begin
Important: This section applies to DCSSs with
special options only. The workaround in this section is error-prone
and requires utmost care. Erroneous parameter values for the described
CP commands can render a DCSS unusable. Use this workaround only if
you really need a DCSS with special options.
Procedure
Perform the following steps to save a DCSS with optional
properties:
- Unmount the DCSS.
Example: Enter this command to unmount a DCSS
with the device node
/dev/dcssblk0:
# umount /dev/dcssblk0
- Use the CP DEFSEG command to newly define
the DCSS with the required properties.
Example: Enter this command to newly define
a DCSS,
mydcss, with the range
80000-9ffff,
segment type
sr, and the
loadnshr operand:
# vmcp defseg mydcss 80000-9ffff sr loadnshr
Note: If your DCSS device maps to multiple DCSSs as defined
to z/VM, you must perform
this step for each DCSS. Be sure to specify the command correctly
with the correct address ranges and segment types. Incorrect specifications
can render the DCSS unusable.
- Use the CP SAVESEG command to save the DCSS.
Example: Enter this command
to save a DCSS
mydcss:
# vmcp saveseg mydcss
Note: If your DCSS device maps to multiple DCSSs as defined
to z/VM, you must perform
this step for each DCSS. Omitting this step for individual DCSSs can
render the DCSS device unusable.
Reference
See z/VM: CP Commands and
Utilities Reference, SC24-6268 for details
about the DEFSEG and SAVESEG CP commands.