DS(4) COMMAND REFERENCE DS(4)
NAME
ds - SCSI Winchester disk
DESCRIPTION
The files /dev/dssd* and /dev/rdssd* are special files
(devices) that provide access to SCSI Winchester disks. All
Winchester (hard) disks attached to UTek workstations are
connected by a Small Computer Systems Interface bus. A
drive must be prepared by scsifmt(8) and newfs(8) before it
can be used as a file system. Each file system and paging
partition should be entered into fstab(5) so UTek can
configure them automatically.
The letters sd in the device names refer to slot number and
device number, respectively. The slot number is that of the
workstation SCSI bus interface. The device number depends
on the SCSI bus controller address of the disk controller.
The suffix * is a letter from a to p indicating which
partition of the disk is to be used. The disk drive may be
referred to without the suffix, but most actual uses of the
disk require a specific suffix to be provided.
The slot number in the device name is the number of the slot
that has the SCSI bus interface. Some workstations allow
optional SCSI bus interfaces in expansion slots. All
provide a primary interface on the main board, whose slot
number is arbitrarily numbered /
0.
The device number is the SCSI bus address of the target
controller, multiplied by two, expressed as a hexadecimal
digit. The allowable device numbers are therefore the even
hexadecimal digits. The odd hexadecimal digits would
represent an additional logical unit attached to the same
controllers, but no such devices are currently offered or
are likely to be offered on UTek-based workstations.
The partition suffix is a letter from a to p which
indicates the part of the disk which should be accessed.
UTek imposes a structure on the disk so that it can verify
and enforce proper access to it. The first one or two
cylinders at the front of a disk contain information that
controls usage of the disk. The first block contains a
complete logical and physical description of the disk,
including the allocation of space on the disk to partitions.
Sixteen partitions are supported:
Partitions Suffix Usage
_______________________________________________
0 a data (root on first disk)
1 b swap (may be empty)
2 c data (optional)
3 d data (optional)
Printed 4/6/89 1
DS(4) COMMAND REFERENCE DS(4)
4 e data (optional)
5 f data (optional)
6 g data (optional)
7 h data (optional)
8 i reserved
9 j reserved
10 k reserved
11 l all allocatable space
12 m diagnostics
13 n manufacturer's defects
14 o maintenance
15 p whole disk
The last five partitions are used for UTek disk management.
Partition l keeps track of all allocatable space, and
should not be used for a file system. The diagnostics
partition is space set aside for testing the disk without
disturbing user data. The manufacturer's defects partition
is not used for SCSI based disk drives. The maintenance
partition is the first few cylinders of the disk, already
described. The whole disk partition provides access to
everything on the disk for maintenance purposes (e.g.,
formatting).
The first eight partitions are available to the user. By
convention, partition a is the first (perhaps only) data
partition, and partition b is swap space (if any). The
remaining six user partitions are typically not used, but
are available for the rare circumstances in which a drive is
to be divided into multiple file systems. It is highly
recommended that partition b be used only for swap space
and that all remaining space be allocated to partition a.
The raw disk ( /dev/rdssd* ) is formatted with 512 byte
blocks. All reads, writes and seeks should be multiples of
512 bytes.
DIAGNOSTICS
dssd: unformatted or bad format
The disk has not been prepared by scsifmt(8) or the
disk hardware is broken. This will make the open(2)
fail unless it is for the whole disk partition.
dssd: invalid maintenance block
The disk has not been prepared by scsifmt(8) or some
formatting information has been clobbered.
dssd: sense failed
After a problem was encountered during a SCSI
transaction, UTek could not communicate properly
with the target SCSI controller. This usually
indicates a problem with the SCSI interface or
Printed 4/6/89 2
DS(4) COMMAND REFERENCE DS(4)
target controller.
dssd*: error: recovered read data with method
Disk block number block
An recoverable read/write error was encountered. The
driver is informing the user that a spot on the disk
had a problem. The user should keep track of block.
If the same block is seen more than once, run
reassign(8) to stop using that block. (This message
should occur very rarely.)
dssd*: error: sense key = key, extended sense = sense
Disk block number block
An unrecoverable read/write error was encountered,
or some other catastrophic problem occurred. The
meanings of key and sense are too numerous and
controller-dependent to list. If sense is printed
out as 11, then the problem is a hard read error,
and the second line indicates the block value which
should be provided to reassign(8). For some other
errors the second line may not be printed.
FILES
The following special files are provided for the primary
disk drive:
/dev/ds00a The root file system partition as a block
device. Use this for fstab(5), mount(8),
fsck(8), and newfs(8).
/dev/ds00b The primary swap partition as a block device.
Use this for fstab(5).
/dev/rds00a The root file system partition as a raw device.
Use this for mkfs(8).
/dev/rds00o The maintenance partition as a raw device. Use
this for mkboot(8).
/dev/rds00p The whole disk partition as a raw device. Use
this for scsifmt(8).
RETURN VALUE
If an error occurs, the call returns -1 and one of the
following values is left in errno:
[ENODEV] You have attempted to open a nonexistent or
unformatted drive.
[ENXIO] You have attempted to read or write beyond the
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DS(4) COMMAND REFERENCE DS(4)
end of the partition.
[EIO] An unrecoverable I/O error has occurred.
CAVEATS
Turning off the disk drive while it is in use may damage the
file system or crash the workstation.
SEE ALSO
fstab(5), newfs(8), and scsifmt(8).
Printed 4/6/89 4
%%index%%
na:192,77;
de:269,3097;3630,2068;
fi:8126,905;
di:5698,908;6870,1256;
rv:9031,396;9691,99;
ca:9790,188;
se:9978,202;
%%index%%000000000150