KVM vs IBM z/VM

KKVM9.2Visit IBM z/VM8.5Visit

Higher score K KVM #1 in Server Virtualization Software 9.2/10 Free plan Free plan✓ 0 of 2 features Explore KVM

vs

IBM z/VM #5 in Server Virtualization Software 8.5/10 Paid ✓ 0 of 2 features Visit IBM

• KVM fits best

  Linux teams building self-hosted virtualization

• IBM z/VM fits best

  IBM Z and LinuxONE large-scale consolidation

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Side by side

Feature	KKVM 9.2/10 Visit ↗	IBM z/VM 8.5/10 Visit ↗
At a glance
Editor score	9.2	8.5
Ranking	#1 in Server Virtualization Software	#5 in Server Virtualization Software
Best for	Linux teams building self-hosted virtualization	IBM Z and LinuxONE large-scale consolidation
Pricing model	Free	Paid
Starting price	Free plan	Not checked yet
Free plan	✓ (best)	—
Free trial	—	—
Deployment	Self-hosted	Self-hosted
Support	Docs	Docs
Features KVM 0/2 · IBM z/VM 0/2
Live migration	Not checked yet	Not checked yet
Central management	Not checked yet	Not checked yet
Specs
Deployment	Not checked yet	Not checked yet
Hypervisor type	Not checked yet	Not checked yet
VMs per host	Not checked yet	Not checked yet
Guest OS support	Not checked yet	Not checked yet
Our review
Pros	Runs unmodified Linux and Windows guest images with virtualized hardware Supports nested virtualization, live migration and VFIO device assignment Open source and integrated into the Linux kernel, with an ioctl-based API	Hosts hundreds to thousands of guest servers on one physical system Single System Image clustering coordinates up to four z/VM systems Virtualizes shared processor, memory, storage and I/O resources
Cons	Requires Linux hosts and userspace tooling such as QEMU for VM management Not a standalone desktop or web application GPU virtualization depends on related Linux components	Supports IBM Z and LinuxONE servers, limiting host-platform choice Paid product with no free plan Public support channel listed is documentation
Our verdict	KVM is an open-source virtualization component integrated into the Linux kernel. It provides hardware-assisted full virtualization for teams that want to run and manage virtual machines on Linux hosts. KVM can run unmodified Linux and… Read the review →	IBM z/VM is an operating system and hypervisor for IBM Z and LinuxONE servers. It is aimed at enterprise teams consolidating large server workloads on those systems, as well as organizations using them for production, testing or… Read the review →

Strengths and trade-offs

• KVM — where it wins

  • Runs unmodified Linux and Windows guest images with virtualized hardware
  • Supports nested virtualization, live migration and VFIO device assignment
  • Open source and integrated into the Linux kernel, with an ioctl-based API

  Where it doesn't

  • Requires Linux hosts and userspace tooling such as QEMU for VM management
  • Not a standalone desktop or web application
  • GPU virtualization depends on related Linux components

• IBM z/VM — where it wins

  • Hosts hundreds to thousands of guest servers on one physical system
  • Single System Image clustering coordinates up to four z/VM systems
  • Virtualizes shared processor, memory, storage and I/O resources

  Where it doesn't

  • Supports IBM Z and LinuxONE servers, limiting host-platform choice
  • Paid product with no free plan
  • Public support channel listed is documentation

• KKVM9.2/10 · Free plan

  A flexible Linux hypervisor foundation for teams managing VMs with tools such as QEMU.

  Explore KVMFull verdict →
• IBM z/VM8.5/10 · Paid

  A fit for large-scale IBM Z and LinuxONE consolidation, not cross-platform virtualization.

  Visit IBMFull verdict →