Displaying hardware and hypervisor information

Ubuntu 22.04 LTS LPAR mode z/VM guest KVM guest

You can display information about the physical and virtual hardware on which your Linux® instance runs.

About this task

This procedure describes how to use /proc/sysinfo. Alternatively, you can use the zname - Obtain information about the IBM Z hardware and zhypinfo - obtain information about virtualization layers on IBM Z commands, provided by the qclib package. Use apt install qclib to install the package.

Procedure

Issue the following command:

# cat /proc/sysinfo

The output of the command is divided into several blocks.

The first two blocks provide information about the mainframe hardware.
The third block provides information about the LPAR on which the Linux instance runs, either in LPAR mode or as a guest of a hypervisor.
Further blocks are present only if the Linux instance runs as a guest of a hypervisor. The field names in these sections have a prefix, VM<nn>, where <nn> is the hypervisor level.
If the hypervisor runs in LPAR mode, there is only one such block, with prefix VM00. If the hypervisor runs as a guest of another hypervisor, there are multiple such blocks with prefixes VM00, VM01, and so on. The highest prefix number describes the hypervisor that is closest to the Linux instance.

You can use the information from /proc/sysinfo, for example, to verify that a guest relocation has taken place.

The following example shows the command output for an instance of Linux as a KVM guest.

Example:

# cat /proc/sysinfo
Manufacturer:         IBM
...
LPAR Number:          9
...
LPAR Name:            LP4KVM09 
...
LPAR Extended Name:   Partition 9 KVM Host
LPAR UUID:            93724168-fda3-429b-8b28-a5d245dcb3ff
...
VM00 Name:            Linux in
VM00 Control Program: KVM/Linux
VM00 Adjustment:      1000
VM00 CPUs Total:      4
VM00 CPUs Configured: 4
VM00 CPUs Standby:    0
VM00 CPUs Reserved:   0
VM00 Extended Name:   Linux instance 42
VM00 UUID:            82038f2a-1344-aaf7-1a85-2a7250be2076

The fields with prefix LPAR include information that identifies and labels the partition:

Number: shows a number that identifies the partition within the mainframe.
Name: shows a partition name of up to 8 characters, as assigned on the HMC.
Extended Name: depending on your hardware, this field can contain an extended partition name, it can be empty, or it might be omitted.
UUID: shows the universally unique identifier (UUID) of the partition.
This field is present only if a UUID is assigned to the partition. On hardware that does not support UUIDs for partitions, this field is always omitted.

The fields with prefix VM<nn> show the following information:

Name

Depends on your hypervisor, z/VM® or KVM:

z/VM: shows the name of the z/VM guest virtual machine according to the z/VM directory.

KVM: shows the name of the virtual server according to the domain XML on the KVM host. Long names are truncated to 8 characters. The full name is always shown in the Extended Name field (see Extended Name (KVM only).

Control Program

shows hypervisor information.

Adjustment

does not show useful information for Linux on IBM® Z.

CPUs Total

shows the number of virtual CPUs that the hypervisor provides to Linux.

CPUs Configured

shows the number of virtual CPUs that are online to Linux.

CPUs Standby

for Linux on z/VM, shows the number of virtual CPUs that are available to Linux but offline.

CPUs Reserved

for Linux on z/VM, shows the number of extra virtual CPUs that z/VM could make available to Linux. This is the difference between the maximum number of CPUs in the z/VM directory entry for the guest virtual machine and the number of CPUs that are currently available to Linux.

For Linux on KVM, this number is always 0.

Extended Name (KVM only)

shows the name of the virtual server as specified in the domain XML on the KVM host. See also Name.

UUID (KVM only)

shows the universally unique identifier (UUID) according to the domain XML on the KVM host. If you do not specify an identifier, libvirt generates a UUID when creating a virtual server definition.