1*61595Sbostic.\" Copyright (c) 1980, 1991, 1993 2*61595Sbostic.\" The Regents of the University of California. All rights reserved. 320653Smckusick.\" 447675Scael.\" %sccs.include.redist.man% 520653Smckusick.\" 6*61595Sbostic.\" @(#)drum.4 8.1 (Berkeley) 06/05/93 747675Scael.\" 847675Scael.Dd 947675Scael.Dt DRUM 4 1047675Scael.Os BSD 4 1147675Scael.Sh NAME 1247675Scael.Nm drum 1347675Scael.Nd paging device 1447675Scael.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. 1947675Scael.Sh FILES 2047675Scael.Bl -tag -width /dev/drum 2147675Scael.It Pa /dev/drum 2247675Scael.El 2347675Scael.Sh HISTORY 2447675ScaelThe 2547675Scael.Nm 2647675Scaelspecial file appeared in 2747675Scael.Bx 3.0 . 2847675Scael.Sh BUGS 2920653SmckusickReads from the drum are not allowed across the interleaving boundaries. 3047675ScaelSince these only occur every .5Mbytes 3120653Smckusickor so, 3220653Smckusickand since the system never allocates blocks across the boundary, 3320653Smckusickthis is usually not a problem. 34