2.9BSD/usr/man/man4/intrlve.4

.TH INTRLVE 4
.UC
.SH NAME
intrlve \- file system interleaving
.SH DESCRIPTION
File system interleaving is achieved by encoding information
in the minor device numbers of the disks across which the
interleaving is to take place.
.PP
The octal representation of the minor device number is encoded
\fIidp\fP, where \fIi\fP is an interleave flag, \fId\fP is a physical
drive number, and \fIp\fP is a partition (subsection) within
a physical unit.  If \fIi\fP is 0, no interleaving takes place.
If \fIi\fP is 1, the minor device consists of the specified
partition on drives number 0 through \fId-1\fP and successively
numbered blocks are distributed across the drives in rotation.
.SH SEE ALSO
dvhp(4), hk(4), hp(4), rm(4), rp(4), xp(4)
.SH DIAGNOSTICS
None.
.SH BUGS
Raw device drivers don't work on interleaved devices.  Thus any
file system maintainance program must refer to disk files by
their block (non-raw) names.  Some programs (notably
.IR fsck (8))
automatically translate a block device name to its raw counterpart
and will fail miserably.