>>> On 2/17/2015 at 02:07 AM, "Pavelka, Tomas" <tomas.pave...@ca.com> wrote: > Could you elaborate on what are the most important things that z/VM provides > that KVM does not? I occasionally get questions from people that heard > somewhere that KVM will replace z/VM on the mainframe but can't give answers > because I don't really know anything about KVM.
Berthold gave a decent list of items. I would add to that - More dynamic capabilities, even for non-privileged guests. I can't count the number of times I wanted to add a device to a KVM guest and had to wait until it was shutdown and restarted before I could use it. - Better sharing capabilities - Really good performance data collection - Better isolation/separation of guests - Better over-commit of resources - CP Privilege classes - External Security Manager (ESM) interface(s) - DCSS - xip2fs - Named Saved Systems - CP USER DIRECT is a lot easier for a human to parse than KVM's XML files. But in large part, z/VM is "better" because of the ISV ecosystem around it. There are a huge number of management tools out there for z/VM (which can also be a problem for shops to figure out which are the ones they want). Being so new, KVM really has nothing like that. I like libvirt, but it also is not yet very mature. VMware is the dominant hypervisor in the distributed world, and will likely remain so for some time. A big part of that are the management tools that VMware creates. In the mainframe world, z/VM is the same way, but from a multiplicity of vendors, not just IBM. I'm sure other people could add a lot of items to this list, since I just rattled this off from the top of my head. I like KVM and think it's cool. SUSE uses it for our internal Build Service for System z, which is for us a mission critical application. I'm just not ready to recommend it to customers for _their_ business critical workload because it hasn't been used in the "real world" enough yet. Mark Post ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
