1*47675Scael.\" Copyright (c) 1980, 1991 Regents of the University of California. 2*47675Scael.\" All rights reserved. 320653Smckusick.\" 4*47675Scael.\" %sccs.include.redist.man% 520653Smckusick.\" 6*47675Scael.\" @(#)drum.4 6.2 (Berkeley) 03/28/91 7*47675Scael.\" 8*47675Scael.Dd 9*47675Scael.Dt DRUM 4 10*47675Scael.Os BSD 4 11*47675Scael.Sh NAME 12*47675Scael.Nm drum 13*47675Scael.Nd paging device 14*47675Scael.Sh DESCRIPTION 1520653SmckusickThis file refers to the paging device in use by the system. 1620653SmckusickThis may actually be a subdevice of one of the disk drivers, but in 1720653Smckusicka system with paging interleaved across multiple disk drives 1820653Smckusickit provides an indirect driver for the multiple drives. 19*47675Scael.Sh FILES 20*47675Scael.Bl -tag -width /dev/drum 21*47675Scael.It Pa /dev/drum 22*47675Scael.El 23*47675Scael.Sh HISTORY 24*47675ScaelThe 25*47675Scael.Nm 26*47675Scaelspecial file appeared in 27*47675Scael.Bx 3.0 . 28*47675Scael.Sh BUGS 2920653SmckusickReads from the drum are not allowed across the interleaving boundaries. 30*47675ScaelSince these only occur every .5Mbytes 3120653Smckusickor so, 3220653Smckusickand since the system never allocates blocks across the boundary, 3320653Smckusickthis is usually not a problem. 34