Red Hat Training

A Red Hat training course is available for Red Hat Enterprise Linux Creating a snapshot for the current domain

The virsh snapshot-create-as domain command creates a snapshot for the domain with the properties specified in the domain XML file (such as <name> and <description> elements). If these values are not included in the XML string, libvirt will choose a value. To create a snapshot run:
# virsh snapshot-create-as domain {[--print-xml] | [--no-metadata] [--reuse-external]} [name] [description] [--diskspec] diskspec]
The remaining options are as follows:
  • --print-xml creates appropriate XML for snapshot-create as output, rather than actually creating a snapshot.
  • --diskspec option can be used to control how --disk-only and external checkpoints create external files. This option can occur multiple times, according to the number of <disk> elements in the domain XML. Each <diskspec> is in the form disk[,snapshot=type][,driver=type][,file=name]. To include a literal comma in disk or in file=name, escape it with a second comma. A literal --diskspec must precede each diskspec unless all three of <domain>, <name>, and <description> are also present. For example, a diskspec of vda,snapshot=external,file=/path/to,,new results in the following XML:
    <disk name=’vda’ snapshot=’external’>
       <source file=’/path/to,new’/>
  • --reuse-external creates an external snapshot reusing an existing file as the destination (meaning this file is overwritten). If this destination does not exist, the snapshot request will be refused to avoid losing contents of the existing files.
  • --no-metadata creates snapshot data but any metadata is immediately discarded (that is, libvirt does not treat the snapshot as current, and cannot revert to the snapshot unless snapshot-create is later used to teach libvirt about the metadata again). This option is incompatible with --print-xml.