ra(4)ra(4)Namera - MSCP disk interface
Syntax
For UNIBUS, Q-bus:
controller uda0 at uba?
controller uq0 at uda0 csr 0172150 vector uqintr
disk ra0 at uq0 drive 0
For VAX BI:
controller kdb0 at vaxbi0 node 4
controller uq0 at kdb0 vector uqintr
disk ra0 at uq0 drive 0
controller bvpssp0 at aio1 vector bvpsspintr
disk ra0 at bvpssp0 drive 0
For MSI Bus:
adapter msi0 at nexus?
controller dssc0 at msi0 msinode 0
disk ra0 at dssc0 drive 3
For VAX CI/HSC:
adapter ci0 at nexus?
adapter ci0 at vaxbi? node?
controller hsc0 at ci0 cinode 6
disk ra0 at hsc0 drive 3
Description
Prior to Version 2.0, this device was referenced by
This is a driver for all DIGITAL MSCP disk controllers. All con‐
trollers communicate with the host through a packet-oriented protocol
termed the Mass Storage Control Protocol (MSCP).
The following rules are used to determine the major and minor numbers
that are associated with an type disk. There is a range of major num‐
bers used to represent disks. Each major number represents 32 disks.
For this reason, the first major number associated with disks repre‐
sents logical unit number 0 through logical unit number 31. Similarly
the second major number represents logical unit number 32 through logi‐
cal unit number 63. The minor number is used to represent both the
logical unit number and partition. A disk partition refers to a desig‐
nated portion of the physical disk. To accomplish this, the 8-bit
minor number is broken up into two parts. The low three bits of the
minor number specify a disk partition. These three bits allow for the
naming of eight partitions. The partitions are named a,b,c,d,e,f,g and
h. The upper five bits of the minor number specify the logical unit
number within a group of 32 disks.
The device special file names associated with disks are based on the
following conventions, which are closely associated with the minor num‐
ber assigned to the disk. The standard device names begin with for the
block special file and for the raw (character) special file. Following
the is the logical unit number and then a letter, a through h, to rep‐
resent the partition. Throughout this reference page, the question
mark (?) character represents the logical unit number in the name of
the device special file. For example ra?b could represent ra0b, ra1b,
and so on.
The following examples illustrate how the logical unit number is calcu‐
lated given the major and minor number of an disk. For the device spe‐
cial file rra6a, the major number is 60 and the minor number is 48.
The partition is represented by the low 3 bits of the number 48. The
low 3 bits will be 0 which specifies the ``a'' partition. The upper 5
bits of 48 specifies the number 6. The major number is 60. Because 60
is the base major number, it represents the first group of 32 disks.
For this reason, there is no need to adjust the unit number for a high
order grouping. Putting all these pieces together reveals that the
major/minor pair 60/48 refers to the ``a'' partition of logical unit 6.
As another example, the following computation determines the logical
unit number corresponding to the major/minor pair 62,49. The low 3
bits of the minor number gives the number 1, which is the ``b'' parti‐
tion. The upper 5 bits of the minor number gives the number 6. The
major number is 62. Subtracting 62 from the base major number of 60
gives a value of 2. This means that 2 groups of 32 disks preceed the
unit in question. For this reason, the logical unit number is as fol‐
lows: (2 * 32) + 6 = 70. The figure 6 is from the minor number.
Therefore, the major/minor pair 62,49 refers to the ``b'' partition of
logical unit number 70, or rra70b.
The disk can be accessed through either the block special file or the
character special file. The block special file accesses the disk using
the file system's normal buffering mechanism. Reads and writes to the
block special file can specify any size. This avoids the need to limit
data transfers to the size of physical disk records and to calculate
offsets within disk records. The file system may break up large read
and write requests into smaller fixed size transfers to the disk.
The character special file provides a raw interface which allows for
direct transmission between the disk and the user's read or write buf‐
fer. In contrast to the block special file, reads and writes to the
raw interface must be done on full sectors only. For this reason, in
raw I/O, counts should be multiples of 512 bytes (a disk sector). In
the same way, calls should specify a multiple of 512 bytes. A single
read or write to the raw interface results in exactly one I/O opera‐
tion, consequently raw I/O may be considerably more efficient for large
transfers. Multiply buffered I/O operations are possible to any raw
MSCP device. (See for more information.)
Disk Support
This driver handles all disk drives that may be connected to an MSCP-
based controller. Consult the ULTRIX Software Product Description to
determine which controllers are supported for which CPU types and hard‐
ware configurations.
The starting location and length (in 512-byte sectors) of the disk par‐
titions of each drive are shown in the following table. Partition
sizes can be changed by For further information, see
RA60 partitions
disk start length
ra?a 0 32768
ra?b 32768 50160
ra?c 0 400176
ra?d 24298 52416
ra?e 295344 52416
ra?f 347760 52415
ra?g 82928 160000
ra?h 24928 157247
ra?h 281805 265236
RA70 partitions
disk start length
ra?a 0 32768
ra?b 32768 66690
ra?c 0 547042
ra?d 0 99458
ra?e 0 281805
ra?f 99458 447583
ra?g 99458 182347
RA71 partitions
disk start length
ra?a 0 32768
ra?b 32768 131072
ra?c 0 1367310
ra?d 778240 204800
ra?e 983040 204800
ra?f 1187840 179470
ra?g 163840 614400
ra?h 778240 589070
RA72 partitions
disk start length
ra?a 0 32768
ra?b 32768 190464
ra?c 0 1953300
ra?d 1144832 299008
ra?e 1443840 299008
ra?f 1742848 210452
ra?g 223232 921600
ra?h 1144832 808468
RA80 partitions
disk start length
ra?a 0 32768
ra?b 32768 50160
ra?c 0 237212
ra?d 82928 51428
ra?e 134356 51428
ra?f 185784 51428
ra?g 82928 154284
ra?h 0 0
RA81 partitions
disk start length
ra?a 0 32768
ra?b 32768 66690
ra?c 0 891072
ra?d 323840 210538
ra?e 46996 210538
ra?f 680534 210538
ra?g 99458 160000
ra?h 259458 631614
RA82 partitions
disk start length
ra?a 0 32768
ra?b 32768 66690
ra?c 0 1216665
ra?d 99458 220096
ra?e 319554 219735
ra?f 539289 437760
ra?g 99458 877591
ra?h 977049 239616
RA90 partitions
disk start length
ra?a 0 32768
ra?b 32768 127072
ra?c 0 2409680
ra?d 159840 420197
ra?e 580037 420197
ra?f 1000234 840393
ra?g 159840 1680787
ra?h 1840627 535526
RA92 partitions
disk start length
ra?a 0 32768
ra?b 32768 127072
ra?c 0 2940951
ra?d 159840 420197
ra?e 580037 420197
ra?f 1000234 840393
ra?g 159840 1680787
ra?h 1840627 1100324
RD31 partitions
disk start length
ra?a 0 15884
ra?b 15884 10024
ra?c 0 41560
ra?d 0 0
ra?e 0 0
ra?f 0 0
ra?g 25908 15652
ra?h 0 0
RD32 partitions
disk start length
ra?a 0 15884
ra?b 15884 15625
ra?c 0 83236
ra?d 31509 25863
ra?e 57372 25864
ra?f 0 0
ra?g 31509 51727
ra?h 0 0
RD51 partitions
disk start length
ra?a 0 15884
ra?b 15884 5716
ra?c 0 21600
ra?d 0 0
ra?e 0 0
ra?f 0 0
ra?g 0 0
ra?h 0 0
RD52 partitions
disk start length
ra?a 0 15884
ra?b 15884 9766
ra?c 0 60480
ra?d 0 0
ra?e 0 50714
ra?f 50714 9766
ra?g 25650 34830
ra?h 15884 44596
RD53 partitions
disk start length
ra?a 0 32768
ra?b 32768 50160
ra?c 0 138672
ra?d 0 0
ra?e 0 0
ra?f 0 0
ra?g 82928 55744
ra?h 32768 105904
RD54 partitions
disk start length
ra?a 0 32768
ra?b 32768 50160
ra?c 0 311200
ra?d 82928 130938
ra?e 213866 97334
ra?f 0 0
ra?g 82928 228272
ra?h 0 0
RF30 partitions
disk start length
ra?a 0 32768
ra?b 32768 50160
ra?c 0 293040
ra?d 82928 130938
ra?e 213866 79173
ra?f 0 0
ra?g 82928 210111
ra?h 0 0
RF31 partitions
disk start length
ra?a 0 32768
ra?b 32768 66690
ra?c 0 744400
ra?d 0 99458
ra?e 0 281805
ra?f 99458 644942
ra?g 99458 182347
ra?h 281805 462595
RF71 partitions
disk start length
ra?a 0 32768
ra?b 32768 66690
ra?c 0 781440
ra?d 0 99458
ra?e 0 281805
ra?f 99458 681982
ra?g 99458 182347
ra?h 281805 499635
RRD40 (read only) partitions
disk start length
ra?a 0 0
ra?b 0 0
ra?c 0 1171875
ra?d 0 0
ra?e 0 0
ra?f 0 0
ra?g 0 0
ra?h 0 0
RRD50 (read only) partitions
disk start length
ra?a 0 15884
ra?b 15884 33440
ra?c 0 1171875
ra?d 131404 122993
ra?e 254397 122993
ra?f 377390 794485
ra?g 49324 82080
ra?h 131404 1040471
RX33 partitions
disk start length
ra?a 0 2400
ra?b 0 0
ra?c 0 2400
ra?d 0 0
ra?e 0 0
ra?f 0 0
ra?g 0 0
ra?h 0 0
RX50 partitions
disk start length
ra?a 0 800
ra?b 0 0
ra?c 0 800
ra?d 0 0
ra?e 0 0
ra?f 0 0
ra?g 0 0
ra?h 0 0
ESE20 partitions
disk start length
ra?a 0 15884
ra?b 15884 33440
ra?c 0 245757
ra?d 49324 130938
ra?e 180262 65495
ra?f 0 0
ra?g 49324 196433
ra?h 0 0
Usually the ra?a partition is used for the root file system, the ra?b
partition as a paging area. The ra?c partition for pack to pack copy‐
ing because it maps the entire disk.
FilesSee Alsonbuf(4), dkio(4), chpt(8), MAKEDEV(8), uerf(8)ra(4)
