8 VBoxManage reference
When you modify a USB filter using usbfilter modify, you must specify the filter by index (see the output of VBoxManage list usbfilters to find global filter indexes and that of VBoxManage showvminfo to find indexes for individual machines) and by target, which is either a virtual machine or “global”. The properties which can be changed are the same as for usbfilter add. To remove a filter, use usbfilter remove and specify the index and the target.
8.23 VBoxManage sharedfolder add/remove
This command allows you to share folders on the host computer with guest operat- ing systems. For this, the guest systems must have a version of the VirtualBox guest additions installed which supports this functionality.
Shared folders are described in detail in chapter 4.7, Folder sharing, page 68.
8.24 VBoxManage metrics
This command supports monitoring the usage of system resources. Resources are represented by various metrics associated with the host system or a particular VM. For example, the host system has a CPU/Load/User metric that shows the percentage of time CPUs spend executing in user mode over a specific sampling period.
Metric data is collected and retained internally; it may be retrieved at any time with the VBoxManage metrics query subcommand. The data is available as long as the background VBoxSVC process is alive. That process terminates shortly after all VMs and frontends have been closed.
By default no metrics are collected at all. Metrics collection does not start until VBoxManage metrics setup is invoked with a proper sampling interval and the number of metrics to be retained. The interval is measured in seconds. For example, to enable collecting the host processor and memory usage metrics every second and keeping the 5 most current samples, the following command can be used:
VBoxManage metrics setup
Specifying 0 as either the interval or as the number of retained samples disables metric collection again. Note that the VBoxManage metrics setup subcommand discards all samples that may have been previously collected for the specified set of objects and metrics.
The host and VMs have different sets of associated metrics. Available metrics can be listed with VBoxManage metrics list subcommand.
A complete metric name may include an aggregate function. The name has the following form: Category/Metric[/SubMetric][:aggregate]. For example, RAM/Usage/Free:min stands for the minimum amount of available memory over all retained data if applied to the host object.
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