Sunday, June 10, 2018

KVM at Share St.Louis 2018


Yes, we will be at SHARE in St.Louis this August!
See our sessions in the Linux and VM track as follows:


Thursday, May 17, 2018

Knowledge Series: Managing KVM on IBM Z with oVirt

See here for a new entry in our "knowledge" series, providing step-by-step instructions on how to include IBM Z hosts in an oVirt data center.

Friday, May 4, 2018

Ubuntu 18.04 released

Ubuntu Server 18.04 LTS is out! Support for IBM Z is available here.
It ships
  • Linux kernel 4.15,
  • QEMU v2.11, and
  • libvirt v4.0.
As obvious from these package versions, support for IBM z14 is readily in place.

Since this is a so-called LTS (Long Term Support) release providing approx. 5 years of support (in contrast to the usual 9 months of non-LTS releases), it is of particular interest to Ubuntu users interested in a stable environment for production deployments.

Thursday, May 3, 2018

QEMU v2.12 released

QEMU v2.12 is out. Here are the highlights from a KVM on Z perspective:
  • Added support for an interactive bootloader. As always, we strongly recommend to use the existing support in libvirt.
    To enable/disable, add the following element to your guest definition:

       <os>
         <bootmenu enable=’yes|no’ timeout=’n’/>
         ...
       </os>


    The timeout parameter specifies a timeout in milliseconds after which the default entry is chosen.
    Alternatively, set attribute loadparm to PROMPT to enable the boot menu without timeout in the respective disk's element:

       <disk ...>
         <boot order=’1’ loadparm=’PROMPT’/>
         ...
       </disk>


    Example:
    To enable the boot menu for 32 seconds for a guest using a libvirt
    domain XML format follows:

       <domain type=’kvm’>
         <os>

           <bootmenu enable=’yes’ timeout=’32000’/>

           ...
         </os>
  • Exposure of guest crash information: When a guest is started using libvirt and crashes due to disabled wait, wrong interrupts or a program check loop, libvirt will print the information to the guest’s log, typically located at /var/log/libvirt/qemu.
    E.g. a crash due to a disabled wait results in an entry as follows:

       s390: psw-mask=’0xXXXXXXXXXXXXXXXX’, psw-addr=’0xXXXXXXXXXX
             XXXXXX’,crash reason: disabled wait


    Requires  libvirt v4.2.
  • Added support for guests with more than 8TB of memory.

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".
Abstract:
"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.