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LDOMCTL(8) System Manager's Manual (sparc64) LDOMCTL(8)

ldomctlLogical Domain management interface

ldomctl command [argument ...]

The ldomctl program is used to manage logical domains on sun4v systems. It can be used to assign resources to the primary and guest domains, start and stop guest domains from the primary domain, and to display information about domains running on the system.

The following commands are available:

Delete the specified configuration from non-volatile storage.
Save a logical domain configuration to non-volatile storage on the service processor. The configuration will take effect after the primary domain is rebooted. The name of the configuration is taken from the name of the directory which must contain files created with the init-system command. The download is aborted if a configuration with the same name already exists.
Dump the current configuration from non-volatile storage into the current working directory.
Generate files in the current working directory for a logical domain configuration file as described in ldom.conf(5).
List configurations stored in non-volatile storage. Indicate the currently running configuration, and the configuration which will be used next (after rebooting the primary domain) if it differs from the currently running one.
Panic a guest domain. The exact behaviour of this command depends on the OS running in the domain. For OpenBSD the default behaviour is to enter ddb(4).
Select the next logical domain configuration to use (after rebooting the primary domain).
Start a guest domain.
Display status information for domain, or for all domains running on the system.
Stop a guest domain.

A system using factory defaults has a single "factory-default" configuration:

# ldomctl list
factory-default [current]

Create a new configuration based on the defaults:

# mkdir factory-default
# cd factory-default
# ldomctl dump
# cd ..
# cp -R factory-default openbsd
# cd openbsd

A file describing the desired configuration must be created - see ldom.conf(5).

Generate a set of configuration files and download to non-volatile storage. If a configuration with the same name already exists, it must be removed first:

# ldomctl init-system ldom.conf
# cd ..
# ldomctl delete openbsd
# ldomctl download openbsd
# ldomctl list
factory-default [current]
openbsd [next]

Create a virtual disk image for each guest domain:

# dd if=/dev/zero of=/home/puffy/vdisk0 bs=1m count=8192
# dd if=/dev/zero of=/home/salmah/vdisk0 bs=1m count=8192

The minirootfs install media can be used to boot guest domains:

# cp miniroot56.fs /home/puffy/vdisk1
# cp miniroot56.fs /home/salmah/vdisk1

Enable ldomd(8) by adding the following to /etc/rc.conf.local:


Halt the primary domain and reset the machine from ALOM:

# halt
sc> reset -c

The machine will now reset and boot into the new configuration. The primary domain should have less CPUs and memory, since they are now assigned to the guest domains:

# ldomctl status
primary      running      OpenBSD running                   1%
puffy        running      OpenBoot Primary Boot Loader      8%
salmah       running      OpenBoot Primary Boot Loader     12%

Configure the vnet(4) interfaces for the guest domains. This example bridges guest domains into the physical network:

# ifconfig vnet0 up
# ifconfig vnet1 up
# ifconfig bridge0 create
# ifconfig bridge0 add em0 add vnet0 add vnet1 up

Access the console of the first domain and boot it:

# cu -l ttyV0
ok boot disk1

dd(1), ddb(4), vnet(4), ldom.conf(5), ldomd(8)

The ldomctl program first appeared in OpenBSD 5.3.

The ldomctl program was written by Mark Kettenis <>.

July 27, 2019 OpenBSD-current