Copyright (c) 1980 Regents of the University of California.
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@(#)hp.4 4.1 (Berkeley) 05/15/85

C 4 hp - RP06, RM03, RM05, RM80, RP07 MASSBUS moving-head disk disk hp0 at mba0 drive 0 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 ``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.

The origin and size of the pseudo-disks on each drive are as follows:

RP06 partitions
 disk start length cyls
 hp?a 0 15884 0-37
 hp?b 15884 33440 38-117
 hp?c 0 340670 0-814
 hp?g 49324 291280 118-814 

RM03 partitions
 disk start length cyls
 hp?a 0 15884 0-99
 hp?b 16000 33440 100-309
 hp?c 0 131680 0-822
 hp?g 49600 81984 310-822

RM05 partitions
 disk start length cyls
 hp?a 0 15884 0-26
 hp?b 16416 33440 27-81
 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 49856 291346 82-561

RM80 partitions
 disk start length cyls
 hp?a 0 15884 0-36
 hp?b 16058 33440 37-114
 hp?c 0 242606 0-558
 hp?g 49910 82080 115-304
 hp?h 132370 110143 305-558

RP07 partitions
 disk start length cyls
 hp?a 0 15884 0-9
 hp?b 16000 64000 10-49
 hp?c 0 1008000 0-629
 hp?d 528000 15884 330-339
 hp?e 544000 258000 340-499
 hp?f 800000 207850 500-629
 hp?g 528000 479850 330-629
 hp?h 80000 448000 50-329



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 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-pack copying (it maps the entire disk).
On rp06's and rm03's the hp?g partition maps the rest of the pack.
On rm80's, rm05's and rp07's, both hp?g and hp?h are used to map the
remaining cylinders.

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.'

In raw I/O counts should be a multiple of 512 bytes (a disk sector).
Likewise
 seek calls should specify a multiple of 512 bytes.
 FILES
/dev/hp[0-7][a-h] block files

/dev/rhp[0-7][a-h] raw files
 SEE ALSO
hk(4), up(4)
 DIAGNOSTICS
hp%d%c: hard error sn%d mbsr=%b er1=%b er2=%b. An unrecoverable
error occured during transfer of the specified sector of the specified
disk partition. The MASSBUS status register is printed in hexadecimal and
with the error bits decoded if any error bits other than MBEXC and DTABT
are set. In any case the contents of the two error registers are also printed
in octal and symbolically with bits decoded.
(Note that er2 is what old rp06 manuals would call er3; the terminology
is that of the rm disks).
The error was either unrecoverable, or a large number of retry attempts
(including offset positioning and drive recalibration) could not
recover the error.

hp%d: write locked. The write protect switch was set on the drive
when a write was attempted. The write operation is not recoverable.

hp%d: not ready. The drive was spun down or off line when it was
accessed. The i/o operation is not recoverable.

hp%d%c: soft ecc sn%d. A recoverable ECC error occurred on the
specified sector of the specified disk partition. This happens normally
a few times a week. If it happens more frequently than
this the sectors where the errors are occuring should be checked to see
if certain cylinders on the pack, spots on the carriage of the drive
or heads are indicated.
 BUGS
In raw I/O
 read and
 write (2) truncate file offsets to 512-byte block boundaries,
and
 write scribbles on the tail of incomplete blocks.
Thus,
in programs that are likely to access raw devices,
 read, write and
 lseek (2) should always deal in 512-byte multiples.

DEC-standard error logging should be supported.

Bad block forwarding is not yet supported on RP06's.

A program to analyze the logged error information (even in its
present reduced form) is needed.

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.