Announcing z/VM V5.2
IBM z/VM V5.2 enhances scalability for virtualization on System z9 and zSeries, including Linux guests

IBM continues the evolution of its premier virtualization technology with a new release of z/VM Version 5 Release 2 (V5.2). An infrastructure for on demand computing environments can be deployed with IBM System z9 or zSeries servers using the virtualization technology of z/VM. z/VM V5.2 extends the strength of the System z9 and zSeries environments as ideal platforms for integrating applications and data and for consolidating select UNIX, Windows, and Linux workloads on a single physical System z9 or zSeries server. This allows you to run tens to hundreds of virtual Linux servers with the potential to support new workloads, achieve productivity gains, and lower IT costs. z/VM supports Linux on the mainframe and enables Linux servers to share hardware resources and use internal high-speed communications within the System z9 and zSeries environments.

z/VM V5.2 is planned to be available on December 16, 2005.

Improved hosting of Linux servers as guests of z/VM

z/VM V5.2 provides major improvements when operating on System z9 or zSeries servers with large memory configurations. Scalability is improved with the use by the control program (CP) of system memory above 2 GB for a much broader set of operations. Previously, guest page frames had to be moved below 2 GB for many reasons. For Queued Direct Input/Output (QDIO), CP queue-control structures had to reside below 2 GB, as did guest queue-control structures, which were moved below 2 GB when needed. Now I/O can be done using buffers anywhere in real memory, and QDIO structures can reside above 2 GB, as can most CP control blocks. These improvements offer constraint relief for large-real-memory virtual-server environments that are memory-intensive.

z/VM V5.2 provides performance improvements for Small Computer System Interface (SCSI) disk I/O, including QDIO efficiency improvements, paging and spooling optimization and improved Fixed Block Architecture (FBA) emulation efficiency.

z/VM Virtual Systems Management APIs are provided for platform-provisioning applications, including programs developed by independent software vendors (ISVs), for ease of use in creating and managing large numbers of Linux and other virtual images running on z/VM.

The SSL server support that shipped with TCP/IP for z/VM V4.4 and V5.1 provided Red Hat Package Manager (RPM) packages for the Novell SUSE LINUX Enterprise Server SLES7 (Linux kernel 2.4.7) and SLES8 (Linux kernel 2.4.19) distributions. With z/VM V5.2, support is provided for additional SLES distributions, as well as for Red Hat Enterprise Linux AS V3.

z/VM support for the System z9 109 (z9-109):

  • The Crypto Express2 Accelerator-for SSL acceleration-is designed to support clear-key RSA operations and offloads compute-intensive RSA public-key and private-key cryptographic operations required by the SSL protocol. The configurable Crypto Express2 feature is exclusive to the System z9 and is supported by z/VM V5.2. z/VM guest support on System z9 and zSeries systems includes dedicated-queue support for clear-key and secure-key cryptographic functions for z/OS guests, and shared-queue and dedicated-queue support for clear-key cryptographic functions for Linux guests
  • z/VM V5.2 enables VTAM on z/VM and other guests to access OSA-Express Channel Data Link Control (CDLC) channels by supporting OSA-Express2 Open Systems Adapter for NCP (OSN). OSA-Express2 OSN helps eliminate the need for any external medium (and all related hardware) for communications between a VTAM host and a Communication Controller for Linux (CCL) image. Traffic between the two images (operating system and CCL) no longer requires an external Local Area Network (LAN) or ESCON channel-traffic can flow LPAR-to-LPAR. OSA-Express2 OSN provides an efficient method of communication, and is designed to create a secure and seamless integration of the VTAM host and CCL.
  • Virtualization technology allows adapter interruptions to be passed directly to z/VM guests using HiperSockets, Fibre Channel Protocol (FCP), and OSA on the System z9, z990, and z890 servers. A complementary virtualization technology is being introduced for the System z9, z990, and z890 servers. These new hardware assists can allow a cooperating guest operating system to initiate QDIO operations directly to the applicable channel, without interception by z/VM, thereby providing additional performance improvements
  • N_Port ID Virtualization (NPIV) for FCP channels is designed to allow the sharing of a single physical FCP channel among multiple operating-system images, whether in LPARs or as z/VM guests in virtual machines. z/VM exploits this capability, offering improved FCP channel utilization and sharing among operating-system images, with FCP now joining ESCON and FICON in offering channel-sharing through virtualization. This may help to reduce hardware requirements and may help to facilitate infrastructure simplification
  • Support for up to 60 LPARs is exclusive to the System z9 and is supported by z/VM V5.2, V5.1, and V4.4.

Enhancing network virtualization

z/VM V5.2 virtualizes a LAN sniffer to capture network traffic on a z/VM guest LAN or virtual switch (VSWITCH) to help improve problem determination for guest LANs and virtual switches. This capability helps an administrator (or owner of the guest LAN) to capture network data to resolve virtual networking problems. Capabilities are provided to capture and process the data in both Linux and native z/VM environments.

A new MPRoute server has been adapted from z/OS V1.7 to operate on z/VM V5.2 to enhance dynamic routing capabilities.

Other enhancements

  • In addition to improving DirMaint directory management performance in z/VM V5.2, the directory management functions of DirMaint can be more easily integrated with the security management functions of RACF. The coordination of DirMaint and RACF changes help simplify user administration. DirMaint can be configured to notify RACF whenever important changes are made to user definitions and the resources they own. This configuration reduces the administrative effort and skills needed to deploy and manage users and their resources when DirMaint and RACF are used together. By eliminating the need to manually define and manage z/VM resources in RACF, the possibility of incomplete or incorrect RACF configurations is reduced.
  • z/VM V5.2 SCSI support is extended to the lower-priced IBM TotalStorage DS4000 Midrange Disk Systems (formerly FAStT) with the addition of the redundant disk array controller (RDAC) driver. The RDAC includes multi-path attachment with failover support. Multipath failover support is designed for continued access to storage on attached devices even if an element in a path (for example, an adapter, cable, or switch) fails
  • z/VM V5.2 is designed to exploit the capability of dynamically adding and deleting a logical partition (LPAR) name on System z9, z890, and z990 servers by providing facilities to dynamically define and delete logical partitions using CP's dynamic I/O command interface and z/VM HCD/HCM support.

Requires IBM System z9 or zSeries Servers

z/VM V5.2 requires the z/Architecture, and runs only on the IBM System z9 BC and z9 EC and and zSeries (z890, z990, z800, z900) servers.

Realize the benefits of z/VM V5.2

You can put the power of System z9 and zSeries environments to work for you, combining partitioning and z/VM virtualization technology, to help realize the benefits of workload isolation and resource sharing. This power includes:

  • Reliability, availability, and serviceability of IBM mainframes
  • Flexibility to create as many as 60 logical partitions (LPARs) with the System z9
  • Ability to virtually partition each LPAR into hundreds or more virtual machines
  • Ability to virtualize processor, communication, memory, storage, I/O, and networking resources
  • Help with maximizing resources to achieve high system utilization
  • Advanced dynamic resource allocation
  • High-speed communications among LPARs and guests with HiperSockets and guest LANs

For the additional information about z/VM V5.2, refer to

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