date and time created 86/02/17 17:59:27 by sklower

[unix-history] / usr / src / share / man / man4 / man4.vax / uda.4

.\" Copyright (c) 1980 Regents of the University of California.
.\" All rights reserved.  The Berkeley software License Agreement
.\" specifies the terms and conditions for redistribution.
.\"
.\"	@(#)uda.4	6.1 (Berkeley) %G%
.\"
.TH UDA 4 ""
.UC 4
.SH NAME
uda \- UDA-50 disk controller interface
.SH SYNOPSIS
.B "controller uda0 at uba0 csr 0172150 vector udaintr"
.br
.B "disk ra0 at uda0 drive 0"
.SH DESCRIPTION
This is a driver for the DEC UDA-50 disk controller.
The UDA-50 communicates with the host through a packet
oriented protocol termed the Mass Storage Control Protocol (MSCP).
Consult the file
.RI < vax/mscp.h >
for a detailed description of this protocol.
.PP
Files with minor device numbers 0 through 7 refer to various portions
of drive 0;
minor devices 8 through 15 refer to drive 1, etc.
The standard device names begin with ``ra'' followed by
the drive number and then a letter a-h for partitions 0-7 respectively.
The character ? stands here for a drive number in the range 0-7.
.PP
The block files access the disk via the system's normal
buffering mechanism and may be read and written without regard to
physical disk records.  There is also a `raw' interface
which provides for direct transmission between the disk
and the user's read or write buffer.
A single read or write call results in exactly one I/O operation
and therefore raw I/O is considerably more efficient when
many words are transmitted.  The names of the raw files
conventionally begin with an extra `r.'
.PP
In raw I/O counts should be a multiple of 512 bytes (a disk sector).
Likewise
.I seek
calls should specify a multiple of 512 bytes.
.SH "DISK SUPPORT"
This driver handles all drives which may be connected to the
UDA-50.  Drive types per se are not recognized, but rather
the variable length partitions are defined as having an
``infinite'' length and the controller is relied on to return
an error when an inaccessible block is requested.  For
constructing file systems, however the partitions sizes are
required.
The origin and size (in sectors) of the pseudo-disks
on each drive are shown below.  Partitions are not rounded
to cylinder boundaries, as on other drives, because the type
of drive attached to the controller is discovered too late
in the autoconfiguration process to maintain separate partition
tables for each drive.  (The lack of proper drive
type recognition would be more easily dealt with if the partition
tables were read off the drive.)
.PP
.nf
.ta .5i +\w'000000    'u +\w'000000    'u +\w'000000    'u +\w'000000    'u
.PP
RA60 partitions
	disk	start	length
	ra?a	0	15884
	ra?b	15884	33440
	ra?c	0	400176
	ra?g	49324	82080
	ra?h	131404	268772
.PP
RA80 partitions
	disk	start	length
	ra?a	0	15884
	ra?b	15884	33440
	ra?c	0	242606
	ra?g	49324	82080
	ra?h	131404	111202
.PP
RA81 partitions
	disk	start	length
	ra?a	0	15884
	ra?b	15884	33440
	ra?c	0	891072
	ra?d	340670	15884
	ra?e	356554	55936
	ra?f	412490	478582
	ra?g	49324	82080
	ra?h	131404	759668
.DT
.fi
.PP
The ra?a partition is normally used for the root file system,
the ra?b partition as a paging area,
and the ra?c partition for pack-pack copying (it maps the entire disk).
.SH FILES
/dev/ra[0-9][a-f]
.br
/dev/rra[0-9][a-f]
.SH DIAGNOSTICS
.BR "uda: ubinfo %x" .
(VAX 11/750 only.)
When allocating UNIBUS resources, the driver found it already
had resources previously allocated.  This indicates a bug in
the driver.
.PP
.BR "udasa %o, state %d" .
(Additional status information given after a hard i/o error.)
The values of the UDA-50 status register and the internal
driver state are printed.
.PP
.BR "uda%d: random interrupt ignored" .
An unexpected interrupt was received (e.g. when no i/o was
pending).  The interrupt is ignored.
.PP
.BR "uda%d: interrupt in unknown state %d ignored" .
An interrupt was received when the driver was in an unknown
internal state.  Indicates a hardware problem or a driver bug.
.PP
.BR "uda%d: fatal error (%o)" .
The UDA-50 indicated a ``fatal error'' in the status returned
to the host.  The contents of the status register are displayed.
.PP
.BR OFFLINE .
(Additional status information given after a hard i/o error.)
A hard i/o error occurred because the drive was not on-line.
.PP
.BR "status %o" .
(Additional status information given after a hard i/o error.)
The status information returned from the UDA-50 is tacked onto
the end of the hard error message printed on the console.
.PP
.BR "uda: unknown packet" .
An MSCP packet of unknown type was received from the UDA-50.
Check the cabling to the controller.
.PP
The following errors are interpretations of MSCP error messages
returned by the UDA-50 to the host.
.PP
.BR "uda%d: %s error, controller error, event 0%o" .
.PP
.BR "uda%d: %s error, host memory access error, event 0%o, addr 0%o" .
.PP
.BR "uda%d: %s error, disk transfer error, unit %d" .
.PP
.BR "uda%d: %s error, SDI error, unit %d, event 0%o" .
.PP
.BR "uda%d: %s error, small disk error, unit %d, event 0%o, cyl %d" .
.PP
.BR "uda%d: %s error, unknown error, unit %d, format 0%o, event 0%o" .
.SH BUGS
The partition tables are so poorly laid out that they almost
certainly force each site to tailor them to their individual
needs.  The problem is even worse when a site has a mixed collection
of drives.  The best solution would be to read the partition tables
off the drive.