Joined: 22 Sep 2005 Posts: 104 Location: Concord, New Hampshire, USA.
Address space and region are keyword parameters.Address space specifies the type of memory - real or virtual memory(ie.paging).Virtual is default. Region specifies the amount of workspace used to execute a job or job step.
Refer IBM Manual for more info. Let us know what puzzles you in this topic.
cause address space and region are both have the relationship with memory,I don't know the real difference between them.
According to your explaination above,do u mean that address space is the name of the memory,and region is the amount of the memory?
I believe the original question was to distinguish the concept of address space and the regions in an MVS system.
Address Space: An address space is a range of irtual addresses that the operating system assigns to a user or separately running program. This is the area of contiguous virtual addresses available for executing instructions and storing data. The range of virtual addresses in an address space starts at zero and can extend to the highest address permitted by the operating system architecture.
An active MVS system uses many address spaces. There is at least one address space for each job in progress and one address space for each user logged on through TSO, telnet, rlogin or FTP. There are many address spaces for operating system functions, such as operator communication, automation, networking, security, and so on. Within each address space the user can start multiple tasks, using task control blocks or TCBs that allow user multiprogramming.
Region: Address spaces are divided into 2-8 gigabyte units called regions. A region is a block of sequential virtual addresses spanning 2-8 gigabytes, beginning at a 2-gigabytes boundary. In each address space, there is a User Region, a System Region, and in 64-bit architecture, there is a High User Region, that is addressable by programs running in 64-bit mode.
I suppose you need to refer to the relevant MVS primer manual for a better understanding of the MVS concepts.