Hotplug scripts are needed in order to use fancy disk configurations in xl,
like iSCSI disks. The job of hotplug scripts is to locally attach the disk
and present it to blkback as a block device or a regular file.
This change introduces a new xenstore node in the blkback hierarchy, called
"path". This is a straigh replacement for the "params" node, which was used
before.
Hotplug scripts will need to read the "params" node, perform whatever
actions are necessary and then write the "path" node. The hotplug script is
also in charge of detaching the disk once the domain has been shutdown.
Sponsored by: Citrix Systems R&D
This is paired with the Xen series at: