10.7. Guest Requirements and Support Limits

The following requirements and support limits apply to guests that are run on the Hypervisor:

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Table 10.5. Virtualized Hardware
Item	Limitations
CPU	A maximum of 160 virtualized CPUs per guest is supported in Red Hat Enterprise Linux 6. A maximum of 240 virtualized CPUs per guest is supported in Red Hat Enterprise Linux 7.
RAM	Different guests have different RAM requirements. The amount of RAM required for each guest varies based on the requirements of the guest operating system and the load under which the guest is operating. See https://access.redhat.com/articles/rhel-kvm-limits for the maximum and minimum supported RAM for guest machines.
PCI devices	A maximum of 31 virtualized PCI devices per guest is supported. A number of system devices count against this limit, some of which are mandatory. Mandatory devices which count against the PCI devices limit include the PCI host bridge, ISA bridge, USB bridge, board bridge, graphics card, and the IDE or VirtIO block device.
Storage	A maximum of 28 virtualized storage devices per guest is supported, composed of a possible 3 IDE and 25 Virtio.