z/VM: CP Planning and Administration - z/VM - IBM

OverviewReal and Virtual Storage Planning and AdministrationThe following list describes real and virtual storage tasks and where to findinformation about each task:v Configure real storage. To define your real storage configuration, code theSTORAGE system configuration file statement. For more information, seeChapter 18, “Real Storage Planning and Administration,” on page 589 and“STORAGE Statement” on page 222.v Provide virtual storage to virtual machines. The amount of virtual storage CPassigns to a virtual machine when the virtual machine logs on is determined byan operand on the USER statement in the virtual machine’s directory entry. TheUSER statement can also set a maximum storage amount that each particularvirtual machine user can define. Code the mstor operand to specify the maximumvirtual machine storage size that a user can define. (Virtual machine users canenter the DEFINE STORAGE command to redefine their virtual machine storageup to the maximum specified on the USER statement.) For more information, see“USER Directory Control Statement (Control)” on page 572.Note: Allowing large numbers of virtual machines to have large storage sizes(primary address spaces and/or data spaces) may affect real storageavailability. This is discussed in the descriptions of the USER andXCONFIG Directory Control Statements. See “USER Directory ControlStatement (Control)” on page 572 and “XCONFIG ADDRSPACE Operand”on page 583.v Plan for using saved segments. A saved segment is an area of virtual storagethat holds data or reentrant code. Defining frequently used data as savedsegments provides several advantages. For detailed information, refer to thez/VM: Saved Segments Planning and Administration.Auxiliary Storage (Expanded Storage and DASD) Planning andAdministrationThe following sections describe planning and administration tasks for CP-owneddirect access storage devices (DASDs), dedicated DASDs, DASDs for minidisks,DASDs for shared file pools, Expanded Storage, and virtual disk in storage.CP-OwnedDASDsCP-owned DASDs are used for the CP system residence volume, real systempaging, spooling, directory and dump space, and temporary disk space for virtualmachines. Do the following for CP-owned DASDs:v Use HCM and HCD to define the DASD or, if needed, code an RDEVICEstatement in the system configuration file for the DASD. For moreinformation on HCM and HCD, see z/OS and z/VM: Hardware ConfigurationManager User’s Guide and z/VM: I/O Configuration. For more information oncoding the RDEVICE statement, see “RDEVICE Statement (DASD)” on page195.v Format CP-owned DASDs. Before CP can use a DASD as a CP-owned DASD,you must use the CPFMTXA utility, or the Device Support Facilities (ICKDSF)program to format the DASD. However, using ICKDSF is the recommendedmethod to format DASD volumes for CP use. For more information onCPFMTXA, refer to z/VM: CP Commands and Utilities Reference. For moreinformation on ICKDSF, refer to Device Support Facilities User’s Guide andReference.Chapter 1. Planning and Administration Overview 7