hp(4)hp(4)Namehp - MASSBUS disk interface
Syntax
disk hp0 at mba0 drive 0
Description
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.
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'.
In raw I/O, counts should be a multiple of 512 bytes (a disk sector).
Similarly, calls should specify a multiple of 512 bytes.
Standard DIGITAL drive types are recognized according to the MASSBUS
drive type register. The origin and size (in sectors) of the parti‐
tions on each drive are as follows:
RM03 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
RM05 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
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?d 49324 15884 118-155
hp?e 65208 55936 156-289
hp?f 121220 219384 290-814
hp?g 49324 291280 118-814
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?d 49910 15884 115-151
hp?e 68096 55936 152-280
hp?f 125888 120559 281-558
hp?g 49910 192603 115-558
RP05 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
RP07 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
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 program.
Restrictions
In raw I/O, and truncate file offsets to 512-byte block boundaries, and
scribbles on the tail of incomplete blocks. Thus, in programs that are
likely to access raw devices, and should always deal in 512-byte multi‐
ples.
Diagnostics
The following messages are printed at the console and noted in the
error log file:
hp%d%c: hard error sn%d
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 infor‐
mation may be gathered from the system error log file,
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.
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.
The following message is written to the system error log file only:
hp%d%c: soft ecc sn%d
A recoverable ECC error occurred on the specified sector of the named
disk partition. This happens normally a few times a week. If it hap‐
pens more frequently than this, the sectors where the errors are occur‐
ring should be checked to see if certain cylinders on the pack or spots
on the carriage of the drive or heads are indicated.
FilesSee Alsodkio(4), nbuf(4), MAKEDEV(8), uerf(8)
VAX hp(4)