ra(4)

NAME

ra − 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 msinode0
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 uda(.).

This is a driver for all DIGITAL MSCP disk controllers. All controllers 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 which are associated with an ra type disk. All ra disks have the same major number. The minor number is used to represent the both the logical unit number and partition. A disk partition refers to a designated portion of the physical disk. To accomplish this the eight bit minor number is broken up into two parts. The low three bits of the minor number specifies a disk partition. These three bits allow for the naming of eight partitions. The partitions are named a,b,c,d,e,f,g or h. The upper five bits of the minor number specifies the logical unit number. Logical unit numbers therefore are in the range 0 through 31.

The device special file names associated with ra disks are based on the following conventions. These conventions are closely associated with the minor number assigned to the disk. The standard device names begin with ra for the block special file and rra for the raw (character) special file. Following the ra is the logical unit number and then a letter a through h to represent the partition. Through out this reference page the 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 up to ra31b.

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 buffer. 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 a multiple of 512 bytes (a disk sector). Likewise, seek calls should specify a multiple of 512 bytes. A single read or write to the raw interface results in exactly one I/O operation, 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 nbuf(4) 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 hardware configurations.

The starting location and length (in 512 byte sectors) of the disk partitions of each drive are shown in the following table. Partition sizes can be changed by chpt(.). For further information, see dkio(.).

RA60 partitions
diskstartlength
ra?a015884
ra?b1588433440
ra?c0400176
ra?d13140489591
ra?e22099589591
ra?f31058589591
ra?g4932482080
ra?h131404268772

RA70 partitions
diskstartlength
ra?a015884
ra?b1588466690
ra?c0547042
ra?d082574
ra?e0264921
ra?f82574464468
ra?g82574182347
ra?h264921283021

RA80 partitions
diskstartlength
ra?a015884
ra?b1588433440
ra?c0237212
ra?d13140435260
ra?e16666435260
ra?f20192435288
ra?g4932482080
ra?h131404105808

RA81 partitions
diskstartlength
ra?a015884
ra?b1588433440
ra?c0500383
ra?d131404122993
ra?e254397122993
ra?f377390122993
ra?g4932482080
ra?h131404368979

RA82 partitions
diskstartlength
ra?a015884
ra?b1588466690
ra?c01216665
ra?d82574220096
ra?e302670219735
ra?f522405437760
ra?g82574877591
ra?h960165256500

RA90 partitions
diskstartlength
ra?a015884
ra?b15884127072
ra?c02376153
ra?d142956420197
ra?e563153420197
ra?f983350840393
ra?g1429561680787
ra?h1823743552410

RD31 partitions
diskstartlength
ra?a015884
ra?b1588410024
ra?c041560
ra?d00
ra?e00
ra?f00
ra?g2590815652
ra?h00

RD32 partitions
diskstartlength
ra?a015884
ra?b1588415625
ra?c083236
ra?d3150925863
ra?e5737225864
ra?f00
ra?g3150925862
ra?h00

RD51 partitions
diskstartlength
ra?a015884
ra?b158845716
ra?c021599
ra?d00
ra?e00
ra?f00
ra?g00
ra?h00

RD52 partitions
diskstartlength
ra?a015884
ra?b158849766
ra?c060480
ra?d00
ra?e050714
ra?f507149766
ra?g2565034830
ra?h1588434830

RD53 partitions
diskstartlength
ra?a015884
ra?b1588433440
ra?c060480
ra?d00
ra?e050714
ra?f507149766
ra?g4932411156
ra?h1588444596

RD54 partitions
diskstartlength
ra?a015884
ra?b1588433440
ra?c0311200
ra?d49324130938
ra?e180262130938
ra?f00
ra?g49324261876
ra?h00

RF30 partitions
diskstartlength
ra?a015884
ra?b1588433440
ra?c0311200
ra?d49324130938
ra?e180262130938
ra?f00
ra?g49324261876
ra?h00

RF71 partitions
diskstartlength
ra?a015884
ra?b1588466690
ra?c0781440
ra?d082574
ra?e0264920
ra?f82574698866
ra?g82574182347
ra?h264920516520

RRD50 (read only) partitions
diskstartlength
ra?a015884
ra?b1588433440
ra?c01171875
ra?d131404122993
ra?e122993254397
ra?f377390794485
ra?g4932482080
ra?h1314041040471

RX33 partitions
diskstartlength
ra?a02400
ra?b00
ra?c02400
ra?d00
ra?e00
ra?f00
ra?g00
ra?h00

RX50 partitions
diskstartlength
ra?a0800
ra?b00
ra?c0800
ra?d00
ra?e00
ra?f00
ra?g00
ra?h00

ESE20 partitions
diskstartlength
ra?a015884
ra?b1588433440
ra?c0245760
ra?d49324130938
ra?e18026265498
ra?f00
ra?g49324196436
ra?h00

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 copying because it maps the entire disk.

FILES

/dev/ra???
/dev/rra???

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