hp.4

<B>Digital的Unix操作系统VAX 4.2源码</B>

.\" SCCSID: @(#)hp.4	8.1	9/11/90
.TH hp 4 VAX
.SH Name
hp \- MASSBUS disk interface
.SH Syntax
.B "disk hp0 at mba0 drive 0"
.SH Description
.NXR "hp interface" "RM03 disk interface"
.NXR "hp interface" "RM05 disk interface"
.NXR "hp interface" "RM80 disk interface"
.NXR "hp interface" "RP06 disk interface"
.NXR "hp interface" "RP07 disk interface"
.NXR "hp interface" "RP05 disk interface"
.NXR "MASSBUS disk interface" "RM03 disk interface"
.NXR "MASSBUS disk interface" "RM05 disk interface"
.NXR "MASSBUS disk interface" "RM80 disk interface"
.NXR "MASSBUS disk interface" "RP06 disk interface"
.NXR "MASSBUS disk interface" "RP07 disk interface"
.NXR "MASSBUS disk interface" "RP05 disk interface"
.NXR "RM03 disk interface"
.NXR "RM05 disk interface"
.NXR "RM80 disk interface"
.NXR "RP06 disk interface"
.NXR "RP07 disk interface"
.NXR "RP05 disk interface"
Files with minor device numbers 0 through 7 refer to various portions
of drive 0;
minor devices 8 through 15 refer to drive 1, and so forth.
The standard device names begin with `hp' 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 with the system's normal
buffering mechanism and may be read and written without regard to
physical disk records.	There is also a ``raw'' interface 
that 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).
Similarly, 
.PN seek
calls should specify a multiple of 512 bytes.
.PP
Standard DIGITAL drive types are
recognized according to the MASSBUS drive type register.
The origin and size (in sectors) of the partitions
on each drive are as follows:
.NXR "MASSBUS disk interface" "drive types recognized"
.PP
.nf
.ta .5i +\w'000000    'u +\w'000000    'u +\w'000000	'u +\w'000000	 'u
.PP
\fBRM03 partitions\fR
.NXR "RM03 disk" "partitions"
	disk	start	length	cyls
	hp?a	0	15884	0-99
	hp?b	16000	33440	100-308
	hp?c	0	131680	0-822
	hp?d	49600	15884	309-408
	hp?e	65440	55936	409-758
	hp?f	121440	10144	759-822
	hp?g	49600	82144	309-822
.PP
\fBRM05 partitions\fR
.NXR "RM05 disk" "partitions"
	disk	start	length	cyls
	hp?a	0	32768	0-53
	hp?b	32832	66880	54-163
	hp?c	0	500384	0-822
	hp?d	341696	15884	562-588
	hp?e	358112	55936	589-680
	hp?f	414048	86240	681-822
	hp?g	341696	158592	562-822
	hp?h	99712	241984	164-561
.PP
\fBRP06 partitions\fR
.NXR "RP06 disk" "partitions"
	disk	start	length	cyls
	hp?a	0	15884	0-37
	hp?b	15884	33440	38-117
	hp?c	0	340670	0-814
	hp?d	49324	15884	118-155
	hp?e	65208	55936	156-289
	hp?f	121220	219384	290-814
	hp?g	49324	291280	118-814
.PP
\fBRM80 partitions\fR
.NXR "RM80 disk" "partitions"
	disk	start	length	cyls
	hp?a	0	15884	0-36
	hp?b	16058	33440	37-114
	hp?c	0	242606	0-558
	hp?d	49910	15884	115-151
	hp?e	68096	55936	152-280
	hp?f	125888	120559	281-558
	hp?g	49910	192603	115-558
.PP
\fBRP05 partitions\fR
.NXR "RP05 disk" "partitions"
	disk	start	length	cyls
	hp?a	0	15884	0-37
	hp?b	15884	33440	38-117
	hp?c	0	171798	0-410
	hp?d	2242	15884	118-155
	hp?e	65208	55936	156-289
	hp?f	121220	50512	290-410
	hp?g	2242	122408	118-410
.PP
\fBRP07 partitions\fR
.NXR "RP07 disk" "partitions"
	disk	start	length	cyls
	hp?a	0	15884	0-9
	hp?b	16000	66880	10-51
	hp?c	0	1008000 0-629
	hp?d	376000	15884	235-244
	hp?e	392000	307200	245-436
	hp?f	699200	308650	437-629
	hp?g	376000	631850	235-629
	hp?h	83200	291346	52-234
.DT
.fi
.PP
It is unwise for all of these files to be present in one installation,
because there is overlap in addresses and protection becomes
difficult.
The hp?a partition is normally used for the root file system,
the hp?b partition as a paging area,
and the hp?c partition for pack-to-pack copying (it maps the entire disk).
On disks larger than about 205 Megabytes, the hp?h partition
is inserted prior to the hp?d or hp?g partition;
the hp?g partition then maps the remainder of the pack.
All disk partition tables are calculated using the
.MS diskpart 8
program.
.SH Restrictions
.NXR "MASSBUS disk interface" "restricted"
In raw I/O,
.MS read 2
and
.MS write 2
truncate file offsets to 512-byte block boundaries,
and
.PN write
scribbles on the tail of incomplete blocks.
Thus,
in programs that are likely to access raw devices,
.PN read ,
.PN write ,
and
.MS lseek 2
should always deal in 512-byte multiples.
.SH Diagnostics
.NXR "MASSBUS disk interface" "diagnostics"
The following messages are printed at the console and noted
in the error log file:
.PP
.B "hp%d%c: hard error sn%d"
.br
An unrecoverable error occurred during transfer of the specified sector
of the named disk partition.
Either the error was unrecoverable, or a large number of retry attempts
(including offset positioning and drive recalibration) could not
recover the error.  Additional register information may be
gathered from the system error log file,
.PN /usr/adm/syserr/syserr.<hostname>.
.PP
.B "hp%d: write locked"
.br
The write protect switch was set on the drive when a write was
attempted.  The write operation is not recoverable.
.PP
.B "hp%d: not ready"
.br
The drive was spun down or off line when it was
accessed.  The I/O operation is not recoverable.
.PP
During autoconfiguration, one of the following messages may appear
on the console indicating the appropriate drive type was recognized.
The last message indicates the drive is of an unknown type.
.sp
.PP
The following message is written to the system error log file only:
.PP
.B "hp%d%c: soft ecc sn%d"
.br
A recoverable ECC error occurred on the specified sector of the
named disk partition.
This happens normally a few times a week.
If it happens more frequently than this,
the sectors where the errors are occurring should be checked to see
if certain cylinders on the pack or spots on the carriage of the drive
or heads are indicated.
.SH Files
.PN /dev/hp???
.br
.PN /dev/rhp???
.SH See Also
dkio(4), nbuf(4), MAKEDEV(8), uerf(8)