drum(4)drum(4)Namedrum - paging device
This file refers to the paging device in use by the system. This may
actually be a subdevice of one of the disk drivers, but, in a system
with paging interleaved across multiple disk drives, it provides an
indirect driver for the multiple drives.
Reads from the drum are not allowed across the interleaving boundaries.
Because these occur only every .5Mbytes or so, and because the system
never allocates blocks across the boundary, this is usually not a prob‐