display or modify contents of the
host's key-value store
hostctl program provides a generic
interface for accessing key-value stores on the system's host. It is
primarily used for an abstracted way to exchange information with
hypervisors that are supported by the
pvbus(4) subsystem. When given the name of a specific
hostctl will display the
value or list the key names of the subtree. If the key is followed by a
hostctl will write the
new key-value pair to the key-value store.
The options are as follows:
- Use device instead of the default /dev/pvbus0.
- Read the new value for the specified key from the input file.
- Save the returned value in the output file.
- Don't ask for confirmation of any default options.
- Print the type of the underlying driver.
Multiple hypervisor interfaces and key-value stores can be simultaneously available and reached through different device nodes.
- pvbus(4) device unit u file.
The vmt(4) driver provides access to the “guestinfo” information that is available in VMware virtual machines:
# hostctl guestinfo.hostname vm-111.example.com # hostctl guestinfo.ip 192.168.100.111
The xen(4) driver provides access to the XenStore that is available in Xen virtual machines. The pvbus(4) layer abstracts it as a simple key-value interface:
# hostctl device/vif/0/mac fe:e1:ba:d0:27:0f # hostctl device/vif/0/description "My interface"
The XenStore is a virtual filesystem that also provides directories. The directory name can be specified as a key to return the contents, other keys, of the directory:
# hostctl device vfb vbd vif console
Access to the Hyper-V Key-Value Pair exchange interface is provided by the hyperv(4) driver. The pvbus(4) layer abstracts access to several pre-defined key pools: Auto, Guest, External and Guest/Parameters. Available keys can be listed and set:
# hostctl Auto/ FullyQualifiedDomainName IntegrationServicesVersion NetworkAddressIPv4 NetworkAddressIPv6 OSBuildNumber OSName OSMajorVersion OSMinorVersion OSVersion ProcessorArchitecture # hostctl Auto/FullyQualifiedDomainName `hostname`
hostctl program first appeared in
hostctl program was written by