NAME

hp − RP06, RM03, RM05, RM80, RP07 MASSBUS moving-head disk

SYNOPSIS

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, 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
diskstartlengthcyls
hp?a0158840-37
hp?b158843344038-117
hp?c03406700-814
hp?g49324291280118-814

RM03 partitions
diskstartlengthcyls
hp?a0158840-99
hp?b1600033440100-309
hp?c01316800-822
hp?g4960081984310-822

RM05 partitions
diskstartlengthcyls
hp?a0158840-26
hp?b164163344027-81
hp?c05003840-822
hp?d34169615884562-588
hp?e35811255936589-680
hp?f41404886240681-822
hp?g341696158592562-822
hp?h4985629134682-561

RM80 partitions
diskstartlengthcyls
hp?a0158840-36
hp?b160583344037-114
hp?c02426060-558
hp?g4991082080115-304
hp?h132370110143305-558

RP07 partitions
diskstartlengthcyls
hp?a0158840-9
hp?b160006400010-49
hp?c010080000-629
hp?d52800015884330-339
hp?e544000258000340-499
hp?f800000207850500-629
hp?g528000479850330-629
hp?h8000044800050-329

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. 

th Berkeley Distribution  —  5/10/81