PR/SM

In mainframe computing a PR/SM (Processor Resource/System Manager) is a type-1 Hypervisor (a virtual machine monitor) that allows multiple logical partitions to share physical resources such as CPUs, I/O channels and direct access storage devices (DASD). It is integrated with all IBM System z machines.

IBM introduced PR/SM in 1988 with the IBM 3090 processors.[1]

IBM developed the concept of hypervisors in their CP-40 and CP-67, and in 1972 provided it for the S/370 as Virtual Machine Facility/370.[2] IBM introduced the Start Interpretive Execution (SIE) instruction as part of 370-XA on the 3081, and VM/XA versions of VM to exploit it. PR/SM is a type-1 Hypervisor based on the CP component of VM/XA that runs directly on the machine level and allocates system resources across LPAR's to share physical resources. It is a standard feature on IBM System z machines.

References

  1. ↑ Singh, K., Dymoke-Bradshaw, L., Castiglion, T., Hanninen, P., Junior, V. R., & Kappeler, P. (2010). Security on the IBM Mainframe. IBM Redbooks. http://www.redbooks.ibm.com/redbooks/pdfs/sg247803.pdf
  2. ↑ 1990, 2002, Copyright IBM Corp. (2002-04-12). z/VM built on IBM Virtualization Technology General Information Version 4 Release 3.0. GC24-5991-04.