The following limits apply to Red Hat Enterprise Linux Server with KVM virtualization. Red Hat also offers Red Hat Enterprise Virtualization, which offers greater scalability and more advanced features. To see limits for Red Hat Enterprise Virtualization, please see Virtualization limits for Red Hat Enterprise Virtualization.
|Red Hat Enterprise Linux 5 Server with KVM||Red Hat Enterprise Linux 6 Server with KVM||Red Hat Enterprise Linux 7 Server with KVM|
|Maximum number of concurrently running virtual guests||41||41||41|
|Maximum number of virtual CPUs in virtualized guest||16||2402||2402|
|Maximum memory in virtualized guest||512 GB3||4000 GB3,4||4000 GB3,4|
|Minimum memory in virtualized guest||512 MB5||512 MB5||512 MB|
- Supported limits reflect the current state of system testing by Red Hat and its partners. Systems exceeding these supported limits may be included in the Hardware Catalog after joint testing between Red Hat and its partners. If they exceed the supported limits posted here, entries in the Hardware Catalog will be fully supported. In addition to supported limits reflecting hardware capability, there may be additional limits under the Red Hat Enterprise Linux subscription terms. Supported limits are subject to change based on ongoing testing activities.
- For limits using the Xen hypervisor included with Red Hat Enterprise Linux 5, please see this article
- This guest limit does not apply to Red Hat Enterprise Linux with Unlimited Guests. There is no guest limit for Red Hat Enterprise Virtualization, Red Hat Enterprise Linux OpenStack Platform, and the Red Hat Enterprise Linux with Smart Virtualization bundle.
- For Red Hat Enterprise Linux 6.2 and earlier, the maximum is 64 virtual CPUs. In Red Hat Enterprise Linux versions 6.3, 6.4, 6.5, and 6.6, and 7.0, the maximum is 160 virtual CPUs.
- Supports the maximum supported memory in the host, all of which may be allocated to the virtualized guest. 32-bit guests with Physical Address Extension (PAE) support will only be able to access 64 GB. This is a virtual hardware limitation.
- For Red Hat Enterprise Linux 6.2 and earlier, the maximum memory in a virtual machine is 512 GB. For Red Hat Enterprise Linux 6.3, the maximum memory in a virtual machine is 2000 GB.
- This is the recommended limit in text mode. Graphical mode requires 640 MB.