Notes:
1. For each shared segment specified, 64K of virtual storage is reserved. The
number of pages actually saved (via theSAVESYS command) can be less than
a segment. However, only one saved system name can be associated with each
64K request.
2. For each shared named system specified, page zero of the first shared segment
should always be saved via aSA VESYS command.
Loading and Saving Discolltiguous Shared Seglnents
Before a discontiguous saved segment can be attached and detached by name, it
must be loaded and saved. The discontiguous saved segment must be loaded at an
address that is beyond the highest address of any virtual machine to which it will be
attached. It is the system programmer's responsibility to make sure the name seg
ment is loaded at an address that does not overlay the defined virtual machine or
any other named segment that may be attached at the same time.
The load address for the discontiguous saved segment should be just beyond the
largest virtual machine that uses it. If the load address is unnecessarily high, real
storage is wasted because CP must have segment table entries for storage that is
never used.
For example, assume you have fiveCMS virtual machines in your installation. Also
assume that all five use theCMS support for DOS program development and test
ing which is in a 32K segment namedCMSDOS. If each of your five CMS virtual
machines has a machine size of320K you should load the CMSDOS segment just
beyond320K. If you load CMSDOS at a much higher address, for example 512K,
you are wasting real storage. In this case, whenever one of youreMS virtual
machines attaches theCMSDOS segment, CP creates segment table entries for a
544K (512K + 32K) virtual machine. Although the virtual machine cannot refer
to storage addresses beyond320K or below 512K, CP still must have segment
table entries in nonpageable real storage for those virtual addresses.Once the named segment is loaded at the correct address, you can save it by issuing
the CPSA VESYS command. To be sure that the CMS discontiguous saved seg
ment has segment protection, set the storage key for the segment, via theCMS SETKEY command, to something other than X'F' before you save it.
The format of theCMS SETKEY command is: I SETKEY
where:
key
key systemname [startadr]
is the storage protection key, specified in decimal. The valid keys
are0-15. systemname is the name of the saved system or segment for which the storage
protection is being assigned.
startadr is the starting address (in hexadecimal) at which the keys are to be
assigned. The address must be within the address range defined for
the saved system or discontiguous saved segments.Using the
GeneratingSaved Systems 77
1. For each shared segment specified, 64K of virtual storage is reserved. The
number of pages actually saved (via the
a segment. However, only one saved system name can be associated with each
64K request.
2. For each shared named system specified, page zero of the first shared segment
should always be saved via a
Loading and Saving Discolltiguous Shared Seglnents
Before a discontiguous saved segment can be attached and detached by name, it
must be loaded and saved. The discontiguous saved segment must be loaded at an
address that is beyond the highest address of any virtual machine to which it will be
attached. It is the system programmer's responsibility to make sure the name seg
ment is loaded at an address that does not overlay the defined virtual machine or
any other named segment that may be attached at the same time.
The load address for the discontiguous saved segment should be just beyond the
largest virtual machine that uses it. If the load address is unnecessarily high, real
storage is wasted because CP must have segment table entries for storage that is
never used.
For example, assume you have five
assume that all five use the
ing which is in a 32K segment named
machines has a machine size of
beyond
you are wasting real storage. In this case, whenever one of your
machines attaches the
544K (512K + 32K) virtual machine. Although the virtual machine cannot refer
to storage addresses beyond
table entries in nonpageable real storage for those virtual addresses.
the CP
ment has segment protection, set the storage key for the segment, via the
The format of the
where:
key
key systemname [startadr]
is the storage protection key, specified in decimal. The valid keys
are
protection is being assigned.
startadr is the starting address (in hexadecimal) at which the keys are to be
assigned. The address must be within the address range defined for
the saved system or discontiguous saved segments.
Generating