hp - MASSBUS disk interface
hp* at mba? drive ?
The hp driver is a generic MASSBUS disk driver which handles
the standard
DEC controllers. It is typical of a block-device disk driver; block I/O
is described in physio(9).
The script MAKEDEV(8) should be used to create the special
files; if a
special file needs to be created by hand, consult mknod(8).
It is recommended
as a security precaution to not create special files
for devices
which may never be installed.
The first sector of each disk contains both a first-stage
bootstrap program
and a disk label containing geometry information and
partition layouts
(see disklabel(5)). This sector is normally write-protected, and
disk-to-disk copies should avoid copying this sector. The
label may be
updated with disklabel(8), which can also be used to writeenable and
write-disable the sector. The next 15 sectors contain a
second-stage
bootstrap program.
During autoconfiguration or whenever a drive comes on line
for the first
time, or when a drive is opened after all partitions are
closed, the
first sector of the drive is examined for a disk label. If
a label is
found, the geometry of the drive and the partition tables
are taken from
it. If no label is found, a fake label is created by the
driver, enough
so that a real label can be written.
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 packpack 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.
/dev/hp[0-7][a-p] block files
/dev/rhp[0-7][a-p] raw files
hp%d%c: hard error %sing fsbn %d [of %d-%d] (hp%d bn %d cn
%d tn %d sn
%d) mbsr=%b er1=%b er2=%b. An unrecoverable error occurred
during transfer
of the specified filesystem block number, which is a
logical block
number on the indicated partition. If the transfer involved
multiple
blocks, the block range is printed as well. The parenthesized fields
list the actual disk sector number relative to the beginning
of the
drive, as well as the cylinder, track and sector number of
the block.
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 RPER3; 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%c: soft ecc reading fsbn %d [of %d-%d] (hp%d bn %d cn
%d tn %d sn
%d). A recoverable ECC error occurred on the specified sector of the
specified disk partition. If the transfer involved multiple
blocks, the
block range is printed as well. The parenthesized fields
list the actual
disk sector number relative to the beginning of the drive,
as well as the
cylinder, track and sector number of the block. 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, spots on the carriage of the drive or
heads are indicated.
intro(4), disklabel(5), disklabel(8)
The hp driver appeared in 4.0BSD. A new hp driver showed up
in NetBSD
1.1A.
DEC-standard bad144(8) bad-block handling should be used.
DEC-standard error logging should be supported.
A program to analyze the logged error information (even in
its present
reduced form) is needed.
OpenBSD 3.6 March 27, 1991
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