Configure the boot settings of a host

·          ARM hosts do not support IOMMU, CPU isolation, CPU hyper-threading, or nested virtualization configuration. ·          By default, IOMMU is enabled on an ARM host.

 

This feature enables you to configure the boot settings of a host, including HugePages, IOMMU, CPU isolation, CPU hyper-threading, and nested virtualization settings.

• HugePages—Compared to the traditional 4 KB page size, HugePages uses at least 8 GB memory to increase the memory size of the page table in the CPU cache. This increases the TLB hit rate.

• IOMMU—An input/output memory management unit (IOMMU) maps virtual addresses to physical addresses to allow physical devices to operate in a virtual memory system and improve the VM performance.

• CPU isolation—CPU isolation removes the specified CPUs from the CPU scheduling policy of a host. The system will not assign tasks to the isolated CPUs. The isolated CPUs are reserved for VMs and DPDK to ensure that the hosts enabled with DPDK and the VMs can obtain the CPU resources in time.

• CPU hyper-threading—With hyper-threading enabled, each CPU core can run multiple threads to improve the throughput and threading software performance.

• Nested virtualization—Nested virtualization enables VMs to run on a x86 VM or a VM created on a physical host. That VM can provide physical CPU features. Nested virtualization degrades host performance.

Restrictions and guidelines

• The modifications to the boot settings take effect after the host restarts.

• You cannot disable HugePages for a host if the host is enabled with DPDK.

• You cannot disable IOMMU for a host if the NIC of the host uses a VFIO driver.

• If you enable CPU isolation and select CPUs created for CPU hyper-threading, do not disable CPU hyper-threading in the BIOS of physical servers. If you do so, CPU isolation will not take effect. For CPU isolation to operate correctly, enable CPU hyper-threading in the BIOS of the physical servers and reboot them.

• Nested virtualization is not supported by non-physical servers. Use this feature only for testing or demonstration.

Procedure

1. On the top navigation bar, click Resources.

2. From the left navigation pane, select Compute > Host Pool Name > Host Name or Compute > Host Pool Name > Cluster Name > Host Name.

3. Click the Advanced tab.

4. Click the Boot Configuration tab.

5. Configure the HugePages state.

If you enable HugePages, specify the page size and page number.

6. Configure the IOMMU state.

7. Configure the CPU isolation state.

If you enable CPU isolation, click the Edit icon  for a minimum of one NUMA node, select the CPUs to isolate, and then click OK.

8. Configure the CPU hyper-threading state.

9. Configure the nested virtualization state.

10. Click Save.

Parameters

Configure HugePages settings:

• Current State: Current HugePages state of the host.

• HugePages: Configure the HugePages state of the host.

• Page Size: Specify the page size.

• Pages: Specify the number of pages.

Configure IOMMU settings:

• Current State: Current IOMMU state of the host.

• IOMMU: Configure the IOMMU state of the host.

Configure CPUs:

• Current State: Current CPU isolation state of the host.

• CPU Isolation: Configure the CPU isolation state of the host.

• NUMA Node: The number of NUMA nodes equals the number of physical CPUs on the host. The number of CPUs on a NUMA node equals the number of CPU cores (multiply the superscalar value if supported) of each CPU. The NUMA nodes are numbered from 0. Each NUMA node contains CPU, I/O bus, and memory resources.

• Isolated CPUs: Isolated CPUs of the host

• Actions: Actions that operators can perform on the isolated CPUs. To isolate or de-isolate a CPU, click the  icon.

Configure CPU hyper-threading:

• Current State: Current state of CPU hyper-threading on the host. By default, this state is the same as the CPU hyper-threading state of the physical host. If CPU hyper-threading is enabled on the physical host, this state is On. If CPU hyper-threading is disabled on the physical host, this state is Not Supported.

• CPU Hyper-Threading: Set the state of CPU hyper-threading on the host. This parameter is available only when CPU hyper-threading is enabled on the host.

Configure nested virtualization:

• Current State: Current state of nested virtualization on the host.

• Nested Virtualization: Set the state of nested virtualization on the host.