"""A class representing the logical and physical status of a node.
@ivar volumes: a structure as returned from
- L{ganeti.utils.GetVolumeList} (runtime)
+ L{ganeti.backend.GetVolumeList} (runtime)
@ivar instances: a list of running instances (runtime)
@ivar pinst: list of configured primary instances (config)
@ivar sinst: list of configured secondary instances (config)
@type lu: C{LogicalUnit}
@param lu: a logical unit from which we get configuration data
@type nodenames: C{list}
- @param node: the list of node names to check
+ @param nodenames: the list of node names to check
@type requested: C{int}
@param requested: the amount of disk in MiB to check for
@raise errors.OpPrereqError: if the node doesn't have enough disk, or