SET DOSPART

Authorization

General User

Purpose

Use the SET DOSPART command to specify the size of the partition in which you want a program to execute in the CMS/DOS environment.

Operands

nnnnnK

specifies the size of the virtual partition in which you want a program to execute. The value, nnnnnK, may not exceed the amount of user free storage available in your virtual machine.

Note: The size is defined on a 4KB boundary.

You should use this function when you can control the performance of a particular program by reducing the amount of available virtual storage; or, if the default size, which is usually 100KB, is not large enough to contain the program to be run. (The default is established when DOS is set to ON with the SET DOS ON command.) When this happens you can either let CMS attempt to get additional storage contiguous to the end of the partition or you can use the SET DOSPART nnnnnK command to redefine the size of the partition.

Note: The CMS/DOS partition, unlike partitions under DOS, is used only to load and run programs started by the FETCH or LOAD command. Areas allocated by GETVIS are assigned addresses outside the partition but within the user's virtual machine.

OFF

specifies you no longer want to control your virtual machine partition size. When the DOSPART setting is OFF, the storage allocated to the partition is redefined to the default size. CMS tries to allocate the default value of 100KB of contiguous storage. If 100KB is not available, it tries to allocate storage down to a minimum of 20KB.

Initial Setting

DOSPART OFF

Usage Notes

1. When a DOS partition is defined, message DMS1101I is issued to tell you how much space was obtained and where the partition is located.
   Note: It is issued only when you:

   • Enter the command at the terminal
   • Issue it using the CMDCALL command from an EXEC 2 exec
   • Issue it using the ADDRESS CMS instruction from a REXX exec
2. You can issue QUERY DOSPART to display the current setting of the virtual partition size.
3. For SET DOSPART OFF, a default-size partition is defined. If the virtual machine requires more than the default-size partition, use the SET DOSPART nnnnnK command to define a larger partition.
4. Error message DMS333E is given only if DOS is unable to get the amount of storage it needs. For more information on getting more storage, see the CP DEFINE command in z/VM: CP Commands and Utilities Reference.

Messages and Return Codes

• DMS099E CMS/DOS environment not active [RC=40]
• DMS109S Virtual storage capacity exceeded [RC=104]
• DMS333E nnnnnK bytes of contiguous free storage are not available to establish the DOS partition at location 20000 [RC=24]
• DMS1101I nnnnnK DOS partition defined at hexadecimal location xxxxxx [RC=0]

Additional system messages may be issued by this command. The reasons for these messages and their location are: