Thursday, April 12, 2018

White Paper: Exploiting HiperSockets in a KVM Environment Using IP Routing with Linux on Z

Our performance group has published a new white paper titled "Exploiting HiperSockets in a KVM Environment Using IP Routing with Linux on Z".
"The IBM Z platforms provide the HiperSockets technology feature for high-speed communications. This paper documents how to set up and configure KVM virtual machines to use HiperSockets with IP routing capabilities of the TCP/IP stack.
It provides a Network Performance comparison between various network configurations and illustrates how HiperSockets can achieve greater performance for many workload types, across a wide range of data-flow patterns, compared with using an OSA 10GbE card.
This white paper is available as .pdf and .html.

Wednesday, April 11, 2018

RHEL 7.5 with support for KVM on Z available

Red Hat Enterprise Linux 7.5 is out. From the release notes, available here:
Availability across multiple architectures
To further support customer choice in computing architecture, Red Hat Enterprise Linux 7.5 is simultaneously available across all supported architectures, including x86, IBM Power, IBM z Systems, and 64-bit Arm.
Support for IBM Z is available through the kernel-alt package, as indicated earlier here, which provides Linux kernel 4.14. QEMU ships v2.10 via package qemu-kvm-ma, and libvirt is updated to v3.9.0 for all platforms.
Thereby, all IBM z14 features as previously listed here are available.
Check these instructions on how to get started. 

Monday, March 26, 2018

SLES12 SP3 Updates

SLES12SP3, released late last year, received a couple of mostly performance and security-related updates in support of IBM z14 and LinuxONE through the maintenance web updates.
In particular:

Thursday, February 1, 2018

RHEL 7.5 Beta supports KVM on Z

The Red Hat Enterprise Linux 7.5 Beta ships with support for KVM on Z through the kernel-alt packages. This will essentially ship Linux kernel 4.14.
Here is the respective section from the release notes:
KVM virtualization is now supported on IBM z Systems. However, this feature is only available in the newly introduced user space based on kernel version 4.14, provided by the kernel-alt packages.
See here for further details.

Monday, December 18, 2017

QEMU v2.11 released

QEMU v2.11 is out. Here are the highlights from a KVM on Z perspective:
  • TOD-Clock Epoch Extension Support: Extends the TOD clock beyond the year 2042.
  • Setting sysctl vm.allocate_pgste is now superfluous.
  • Netboot: The network boot firmware sets the client architecture option (93) in the DHCP request to 0x1f ("s390 Basic"). This allows a DHCP server to deliver the correct boot image for IBM Z guests. This is useful in situations where a single DHCP server has to provide network boot images for multiple architectures, e.g. for the purpose of installing operating systems.
  • Added support for virtio-input-ccw and virtio-gpu-ccw. These newly supported devices lay the foundation for applications that require graphical interfaces, which thereby become usable from remote via VNC or SPICE.

Wednesday, December 13, 2017

Performance: Network Storage Protocols in a KVM Environment

Our performance group has published a new white paper titled "Network Storage Protocols in a KVM Environment - NFS/SMB/iSCSI Report" (.pdf and .html).

"iSCSI, NFS, and SMB protocols provide access to storage resources via a TCP/IP network. While iSCSI provides block device access, NFS and SMB are file-level access protocols. In cases where the devices are mounted on the KVM host (as in our case) they could be functionally considered as equivalent when utilized for KVM guest device attachment with image files."

Tuesday, December 12, 2017