For a brief summary of Xapi terminology, see: https://xapi-project.github.io/xen-api/overview.html#object-model-overview Xapi contains functionality to backup and restore metadata about Virtual Machines and Storage Repositories (SRs). The metadata itself is stored in a Virtual Disk Image (VDI) inside an SR. This is used for two purposes; a general backup of metadata (e.g. to recover from a host failure if the filer is still good), and Portable SRs (e.g. using an external hard drive to move VMs to another host). Metadata is only restored as an explicit administrator action, but occurs in cases where the host has no information about the SR, and must locate the metadata VDI in order to retrieve the metadata. The metadata VDI is located by searching (in UUID alphanumeric order) each VDI,…