usr/man/man4/ra.4

.TH RA 4 10/8/81
.UC 4
.SH NAME
ra \- UDA50/RA80 Unibus disk controller and drives
.SH SYNOPSIS
controller uda0 at uba? csr 0177550 vector udintr
.br
disk ra0 at uda0 drive 0
.SH DESCRIPTION
The UDA50 is an intelligent disk controller for the UNIBUS.
It supports the RA80 124MB disk drive.
.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 origin and size of the pseudo-disks on each drive are
as follows:
.PP
.nf
.ta .5i +\w'000000    'u +\w'000000    'u
RA80 124M drive partitions:
        disk    start   length
        ra?a    0       15884
        ra?b    15884   33440
        ra?c    0       237298
        ra?d    0       0
        ra?e    0       0
        ra?f    0       0
        ra?g    49324   82080
        ra?h    131404  105994
.DT
.fi
.PP
It is unwise for all of these files to be present in one installation,
since there is overlap in addresses and protection becomes
a sticky matter.
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).
Both ra?g and ra?h are used to map the
remaining cylinders.
.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 FILES
/dev/ra[0-7][a-h]       block files
.br
/dev/rra[0-7][a-h]      raw files
.SH SEE ALSO
hk(4), hp(4), up(4)
.SH DIAGNOSTICS
\fBra%d%c: hard error sn%d udasa %o, state %d\fR.
.br
\fBra%d%c: hard error sn%d status %o\fR.
An unrecoverable
error occured during transfer of the specified sector of the specified
disk partition.  The contents of the udasa register are printed
in octal and symbolically with bits decoded.  The internal state is also
printed.  In the second form, the MSCP status is printed.
The error was either unrecoverable, or a large number of retry attempts
(including offset positioning and drive recalibration) could not
recover the error.
.PP
\fBra%d%c: hard error sn%d OFFLINE\fR.  The drive was spun down or off
line when it was accessed.  The i/o operation is not recoverable.
.PP
\fBuda%d: random interrupt ignored\fR.  The UDA received an interrupt
before it was initialized.
.PP
\fBuda%d: fatal error (%o)\fR.  A fatal error was noticed in the UDA
interrupt routine.  The contents of udasa are printed.  The controller
will be reinitialized.
.PP
\fBuda%d: [soft|hard] error, controller error, event 0%o\fR.
.br
\fBuda%d: [soft|hard] error, host memory access error, event 0%o, addr 0%o\fR.
.br
\fBuda%d: [soft|hard] error, disk transfer error, unit %d, grp %d, cyl %d,
sec %d, trk %d, lbn %d, retry %d, level %d\fR.
.br
\fBuda%d: [soft|hard] error, SDI error, unit %d, event 0%o, cyl %d\fR.
.br
\fBuda%d: [soft|hard] error, small disk error, unit %d, event 0%o, cyl %d\fR.
.br
\fBuda%d: [soft|hard] error, unknown error, unit %d, format 0%o, event 0%o\fR.
.br
See the driver and the UDA and MSCP manuals.
.SH BUGS
In raw I/O
.I read
and
.IR write (2)
truncate file offsets to 512-byte block boundaries,
and
.I write
scribbles on the tail of incomplete blocks.
Thus,
in programs that are likely to access raw devices,
.I read, write
and
.IR lseek (2)
should always deal in 512-byte multiples.
.PP
A program to analyze the logged error information (even in its
present reduced form) is needed.  Error messages should be more
consistent.
.PP
The partition tables for the file systems should be read off of each
pack, as they are never quite what any single installation would prefer,
and this would make packs more portable.
.PP
Dumps to the swap area on system crashes are not implemented.
.PP
Booting via block zero is not (and will not be) supported.  The ``boot''
program must be loaded from the console storage device.
.PP
Although the device supports unit numbers up to 255, the driver only
supports unit numbers up to 7.