sdc.4

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 4 代码 · 共 211 行

.\" SCCSID: @(#)sdc.4	8.1	9/11/90
.TH sdc 4 VAX
.SH Name
sdc \- RD31, RD32, RD53, RD54, RX33, RX23 Small VAX disk interface
.SH Syntax
.B "controller sdc0 at uba0 csr 0x200c0000 vector sdintr "
.br 
.B "disk rd0 at sdc0 drive 0"
.br
.B "disk rd1 at sdc0 drive 1"
.br
.B "disk rx2 at sdc0 drive 2"
.SH Description				
.NXR "RD31 disk interface"
.NXR "RD32 disk interface"
.NXR "RD53 disk interface"
.NXR "RD54 disk interface"
.NXR "RX33 disk interface"
.NXS "sdc interface" "RD31 disk interface"
.NXS "sdc interface" "RD32 disk interface"
.NXS "sdc interface" "RD53 disk interface"
.NXS "sdc interface" "RD54 disk interface"
.NXS "sdc interface" "RX33 disk interface"
This is a driver for the Digital  Small VAX disk controller.
This disk controller is used by both the workstation and
multiuser configurations of the busless Small VAX processor.
This controller also supports the RX23 floppy disk drive in the
VAXstation 3100 model 30 processor.
.PP
The SDC driver uses the same disk format as the RQDX3 controller.
Winchester disks formatted by the small VAX controller are
compatible with RQDX3 formatted disks, but
not with RQDX1 and RQDX2 formatted disks.
The SDC driver implements dynamic bad block replacement
in the same manner as the RQDX3 controller.
.PP
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 
rd,
for Winchester disk drives 0 and 1 and
rx,
for the diskette drive 2
followed by the drive number and then a letter, a through h,
for partitions 0 through 7.
.PP
The block files access the disk by the system's normal
buffering mechanism and can 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.
One read or write call results in one I/O operation,
so raw I/O is considerably more efficient when
many words are transmitted.  
The names of the raw files conventionally begin with an additional letter
r, for example,
.PN rrx@a .
.PP
In raw I/O, counts should be a multiple of 512 bytes (a disk sector).
In the same way,
.PN seek 
calls should specify a multiple of 512 bytes.
.SH Disk Support
The SDC driver handles RD31, RD32, RD53, and RD54 Winchester disk drives
on drives 0 and 1 and the RX33/RX23 floppy disk drive on drive 2.
The RX33 drive reads and writes both single-density
(400 Kbytes) RX50 floppy
diskettes and double-density double-sided (1200 Kbytes) RX33 diskettes.
The RX23 drive reads and writes high density (18 sectors per track) RX23
floppy diskettes and reads double density (9 sectors per track) RX23
floppy diskettes.
Drive types are recognized in the autoconfiguration process.
For constructing file systems, the partition sizes 
are required.  Partition sizes are the same as those supported by
the MSCP driver,
.MS ra 4 .
Partition sizes can be queried or changed by 
.MS chpt 8 .
.PP
The rd?a partition is usually used for the root file system,
the rd?b partition as a paging area,
and the rd?g partition for the usr file system.
.SH Diagnostics
.NXR "RD32 disk interface" "diagnostics"
The following messages are printed at the console
and written to the system
error log file,
\f(CW/usr/adm/syserr/syserr.\fI<hostname>\fR.
.PP
.B "sd%d:HARD_ERR: cannot read XBN"
.br
The driver cannot read the format information
from the disk during autoconfiguration.
The disk may not be formatted properly.
.PP
.B "sd%d:HARD_ERR: CANNOT RECOVER FROM PREVIOUS BBR"
.br
Bad block replacement was interrupted 
in the middle when the system was last 
halted.
The driver cannot successfully complete the bad block replacement.
Try to recover all the data from the disk and reformat it.
Refer to the 
.I Guide to System Configuration File Maintenance
for additional information.
.PP
.B "sd%d:HARD_ERR: Drive select failed"
.br
The driver cannot select the specified
drive for doing I/O. Make sure the drive
is on line.
.PP
.B "sd%d:HARD_ERR: Invalid cylinder: %d"
.br
The driver tries I/O on a cylinder
outside the valid range for the type of disk
on the drive. 
This is a fatal error caused by the driver and should not happen.
.PP
.B "sd%d:HARD_ERR: Invalid head:%d"
.br
The driver tries I/O on
a head outside the valid range for the type of disk on
the drive.
This is a fatal error caused by the driver and should not happen.
.PP
.B "sd%d:HARD_ERR: Forced Error Modifier set LBN %d"
.br
The forced error bit is set on the specified block.
The block was found to be
bad and has been replaced with a good block,
but the data in the block is bad.
Writing new data into this block will clear the forced error bit.
Refer to the 
.I Guide to System Configuration File Maintenance
for additional information.
.PP
.B "sd%d:HARD_ERR: compare error"
.br
The driver received a compare error for the drive from the controller. 
This should be seen only for the floppy drive.
For hard disks, the bad block will 
get replaced.
.PP
.B "sd%d:HARD_ERR: eccerror"
.br
The driver received an ECC error for the drive from the controller.
.PP
.B "sd%d:HARD_ERR: syncerr"
.br
The driver received a sync error for the drive from the controller. 
If it is the
floppy drive, reinsert the floppy and repeat the command.
.PP
.B "sd%d:HARD_ERR: bad sector"
.br
The controller detected the sector to be bad from the sector's ID field.
This message should appear only for the floppy drive.
For hard disks, the bad block will get replaced.
.PP
.B "sd%d:HARD_ERR: WRITE FAULT"
.br
This is due to an internal error in the drive,
such as an improper supply voltage.
This message should appear only for hard disk drives.
.PP
The following messages are written to the system error file,
\f(CW/usr/adm/syserr/syserr.\fI<hostname>\fR,
but not printed at the console..
.PP
.B "sd:SOFT_ERR: stray interrupt"
.br
An unexpected interrupt was received 
(for example, when no I/O was pending). 
The interrupt is ignored.
.PP
.B "sd:SOFT_ERR: No valid buffer"
.br
An interrupt was received when the driver was not ready to receive one. 
The interrupt is ignored. This should rarely happen.
.PP
.B "sd%d:SOFT_ERR: Command not yet
implemented thru interrupt, command = %c"
.br
An interrupt was received for the command.  This should not happen.
The interrupt is ignored.
.PP
.B "sd%d:SOFT_ERR: Unknown error type,
UDC_CSTAT = %o, UDC_DSTAT = %o, DKC_STAT = %o"
.br
The error type indicated by the controller
for the last I/O is not any of the
common ones. An I/O error is generated.
.SH Files
.PN /dev/rd[0-1][a-f]
.br
.PN /dev/rrd[0-1][a-f]"
.sp
.br
.PN /dev/rx2a"
.br
.PN /dev/rx2c"
.sp
.br
.PN /dev/rrx2a"
.br
.PN /dev/rrx2c"

.SH See Also
dkio(4), nbuf(4), ra(4), rd(4), rx(4), chpt(8), uerf(8)