HP OpenVMS I/O User's Reference Manual |
Disk Drivers |
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Supported Disk Devices and Controllers
To obtain more information about a device, use the DCL command SHOW DEVICE with the /FULL qualifier, the Get Device/Volume Information ($GETDVI) system service (from a program), or the F$GETDVI lexical function (in a command line or command procedure). Disk Driver Device Information lists the information on disk devices returned by $GETDVI.
UDA50
UNIBUS Disk Adapter ![]()
The UDA50 UNIBUS
Disk Adapter is a microprocessor-based disk controller for mass
storage devices that implements the DIGITAL Storage Architecture
(DSA); for more information on the DSA, see
Dual-Pathed DSA Disks.
The UDA50 controller is used to connect any combination of four RA60, RA80, and RA81 disk drives to the UNIBUS. Two UDA50 controllers can be attached to a single UNIBUS for a maximum of eight disk drives per UNIBUS. On the VAX-11/780 processor, the operating system supports one UDA50 on the first UNIBUS, which can accommodate certain other options. Adding a second UDA50 requires a second UNIBUS. With the exception of the first UNIBUS, a maximum of two UDA50 controllers per UNIBUS are supported. If two UDA50 controllers are on a UNIBUS, no other options can be placed on that UNIBUS. The VAX-11/730 processor supports only one UDA50 per UNIBUS.
The UDA50, in implementing DSA, takes over the control of the physical disk unit. The operating system processes request virtual or logical I/O on disks controlled by the UDA50. The operating system maps virtual block addresses into logical block addresses. The UDA50 then resolves logical block addresses into physical block addresses on the disk.
The UDA50 controller corrects bad blocks on the disk by requesting that the disk class driver revector a failing physical block to another, error-free physical block on the disk; the logical block number is not changed (see Bad Block Replacement and Forced Errors for DSA Disks). Any bad blocks that might exist on a disk attached to a UDA50 are transparent to the operating system, which does logical or virtual I/O to such a disk. The UDA50 also corrects most data errors.
KDA50
Disk Controller ![]()
The KDA50 disk
controller is a two-module disk controller that allows the RA-series
DSA disk drives to be attached to Q-bus systems. The KDA50 performs
the same functions as the UDA50 (see
UDA50 UNIBUS Disk Adapter).
KDB50
Disk Controller ![]()
The KDB50 disk
controller is a two-module disk controller that allows the RA-series
DSA disk drives to be attached to BI bus systems, such as the VAX
8200 processor. The KDB50 performs the same functions as the UDA50
(see
UDA50 UNIBUS Disk Adapter).
HSC40,
HSC50, and HSC70 Controllers ![]()
HSC controllers
are high-speed, high-availability controllers for mass storage devices
that implement the DIGITAL Storage Architecture (DSA); for more
information about the DSA, see
Dual-Pathed DSA Disks. An HSC controller is connected to a processor
by a Computer Interconnect (CI) bus. The operating system supports
the use of the HSC controllers in controlling the RA family of disks.
The HSC40 can support up to 12 SDI (standard disk interface) disks from the SA or RA families of disk drives or a combination of up to 12 SDI disk drives and TA-series tape drives.
The HSC70 can support up to 32 SDI disks from the SA or RA families of disk drives or a combination of SDI disk drives and TA-series tape drives.
HSC controllers, in implementing DSA, take over the control of the physical disk unit. System processes request virtual or logical I/O on disks controlled by the HSC controller. The operating system maps virtual block addresses into logical block addresses. The HSC controller then resolves logical block addresses into physical block addresses on the disk.
HSC controllers correct bad blocks on the disk by revectoring a failing physical block to another, error-free physical block on the disk; the logical block number is not changed. The operating system, which performs logical or virtual I/O to such a disk, does not recognize that any bad blocks might exist on a disk attached to an HSC controller. HSC controllers also correct most data errors.
The HSC series of controllers provides access to disks despite most hardware failures. Use of an HSC controller permits two or more processors to access files on the same disk.
| Only one system should have write access to a Files-11 On-Disk Structure Level 1 disk or to a foreign-mounted disk; all other systems should only have read access to the disk. For Files-11 On-Disk Structure Level 2 volumes, the operating system enables read/write access to all nodes that are members of the same cluster. |
SII
Integral Adapter ![]()
The SII integral adapter
on the MicroVAX 3300/3400 processor provides access through the
DIGITAL Storage Systems Interconnect (DSSI) bus to a maximum of
seven storage devices.
The term dual-host refers to pairs of CPUs connected to a bus. In dual-host configurations of MicroVAX 3300/3400 CPUs, the DSSI bus must be connected between the SII integral adapters present on both CPUs.
A maximum of six devices can be connected to the EDA640 adapter, which is implemeneted by the SII chip, DXX chip, and 128K RAM chip, in dual-host configurations.
KFQSA
Adapter ![]()
The KFQSA adapter
allows a maximum of seven storage devices for use on Q-bus systems.
In dual-host configurations of MicroVAX 3800/3900 CPUs, the DSSI bus must be connected between KFQSA adapters present on both CPUs.
A maximum of six devices can be connected to the KFQSA adapter in dual-host configurations.
RQDX3
Disk Controller ![]()
The RQDX3 controller
is a Q-bus controller used with the RD series of Winchester-type
disk drives and the RX33 and RX50 flexible diskette drives.
RA70 and RA90 Disk Drives ![]()
The
RA70 is a 5.25-inch, 280-MB high-performance DSA disk drive that
uses thin-film media. It has an average access time of 27.0 ms and
average seek time of 19.5 ms. The RA70 uses the Standard Disk Interface (SDI)
and the KDA50 controller, and can be dual-ported.
The RA90 is a 1.2 GB disk drive designed with thin-film heads and 9-inch thin-film media with an average seek time of 18.5 ms. The RA90 conforms to DSA and uses the SDI. Both the RA70 and RA90 disk drives can be connected to medium-sized systems with the HSC-series controllers, KDB50, or UDA50 controllers.
RA60 Disk ![]()
The RA60 device uses high-capacity,
removable media that provides 205 MB of usable storage (7.5 million
bits of data per square inch) with transfer rates of 1.9 MB per
second (burst) and 950 Kb per second (sustained). The RA60 belongs
to the DIGITAL Storage Architecture (DSA) family of disk devices
(see
Dual-Pathed DSA Disks). It is
connected to either a UNIBUS Disk Adapter (UDA50) or an HSC50 controller.
Up to four disk drives can be connected to each UDA50. Up to 24
disk drives can be connected to each HSC50.
RA80/RB80/RM80 and RA81 Fixed-Media Disks ![]()
The R80 disk drive is a high-capacity, moving-head disk whose
nonremovable media consists of 14 data surfaces. Depending on how
it is connected to the system, the R80 is identified internally
as an RA80, RB80, or RM80, as follows:
The RA81 is a high-capacity disk drive with nonremovable media that can hold more than 890,000 blocks of data. This translates into more than 455 MB per spindle. The RA81 is connected to a UDA50 or an HSC50 controller. Up to four disk drives can be connected to each UDA50. Up to 24 drives can be connected to each HSC50.
The RA80 and RA81 belong to the DIGITAL Storage Architecture (DSA) family of disk devices (see Dual-Pathed DSA Disks).
RB02 and RL02 Cartridge Disk (VAX Only) ![]()
On VAX systems,
the RL02 cartridge disk is a removable, random-access mass storage
device with two data surfaces. The RL02 is connected to the system
by an RL11 controller that interfaces with the UNIBUS adapter. Up
to four RL02 disk drives can be connected to each RL11 controller.
For physical I/O transfers, the track, sector, and cylinder parameters
describe a physical 256-byte RL02 sector (see
Disk Function Codes).
When the RL02 is connected to an RB730 controller on a VAX-11/730 processor, it is identified internally as an RB02 disk drive. Disk geometry is unchanged and RL02 disk packs can be exchanged between drives on different controllers. Up to four drives can be connected to the RB730 controller.
RC25
Disk (VAX Only) ![]()
On VAX systems, the RC25
disk is a self-contained, Winchester-type, mass storage device that
consists of a disk adapter module, a disk drive, and an integrated
disk controller. The drive contains two 8-inch, double-sided disks.
One of the disks (RCF25) is a sealed, nonremovable, fixed-media
disk. The other disk is a removable cartridge disk that is sealed
until it is loaded into the disk drive. The disks share a common
drive spindle, and together they provide 52 million bytes of storage.
Adapter modules interface the RC25 with either a UNIBUS system or
a Q-bus system.
RD53 and RD54 Disks (VAX Only) ![]()
On VAX systems, the RD53 and RD54 are 5.25-inch, full-height,
Winchester-type drives with average access time of 38 ms and a data
transfer rate of 0.625 MB per second. The RD53 and RD54 have a formatted
capacity of 71 MB and 159 MB, respectively. When used with the RQDX3
controller, the RD53 and RD54 are DSA disks.
See VAXstation 2000 and MicroVAX 2000 Disk Driver for information about using RD series disks on the VAXstation 2000.
RF30 and RF71 Disks ![]()
The RF30 is a 150-MB, 5.25-inch,
half-height disk drive while the RF71 is a 400-MB, full-height disk
drive. The RF30 and RF71 include an embedded controller for multihost
access and a mass storage control protocol (MSCP) server. The RF71
has a peak data transfer rate of 1.5 MB per second with average
seek and access time of 21 ms and 29 ms, respectively.
Both the RF30 and RF71 disks use DIGITAL Storage System Interconnect (DSSI) bus and host adapters.
RK06 and RK07 Cartridge Disks (VAX Only) ![]()
On VAX systems,
the RK06 cartridge disk is a removable, random-access, bulk storage
device with three data surfaces. The RK07 cartridge disk is a double-density
RK06. The RK06 and RK07 are connected to the system by an RK611
controller that interfaces to the UNIBUS adapter. Up to eight disk
drives can be connected to each RK611.
RM03 and RM05 Pack Disks (VAX Only) ![]()
On VAX systems, the RM03
and RM05 pack disks are removable, moving-head disks that consist
of five data surfaces for the RM03 and 19 data surfaces for the
RM05. These disks are connected to the system by a MASSBUS adapter
(MBA). Up to eight disk drives can be connected to each MBA.
RP05 and RP06 Disk (VAX Only) ![]()
On VAX systems, the RP05
and RP06 removable disks consist of 19 data surfaces and a moving
read/write head. The RP06 removable disk has approximately twice
the capacity of the RP05. These disks are connected to the system
by an MBA. Up to eight disk drives can be connected to each MBA.
RP07
Fixed-Media Disk (VAX Only) ![]()
On VAX systems, the RP07
is a 516-MB, fixed-media disk drive that attaches to the MASSBUS
of the VAX-11/780 system. The RP07 transfers data at 1.3 million
bytes per second or as an option at a peak rate of 2.2 million bytes
per second. The nine platters rotate at 3600 rpm and their data
is accessed at an average speed of 31.3 ms. These disks are connected
to the system by an MBA. Up to eight disk drives can be connected
to each MBA.
RRD40
and RRD50 Read-Only Memory (CD-ROM) ![]()
The RRD40
and RRD50 are compact disc read-only memory (CD-ROM) devices that
use replicated media with a formatted capacity of approximately
600 MB.
The RRD40 is a 5.25-inch half-height, front-loading tabletop or embedded device that attaches to the system using either the Small Computer System Interface (SCSI) or Q-bus interface.
The RRD50 is a 5.25-inch, top-loading tabletop device that attaches to the system using a Q-bus interface.
The RRD40 has an average access time of 0.5 second while the average access time for the RRD50 is 1.5 seconds. Both the RRD40 and RRD50 have a data transfer rate of 150 KB per second.
The media for the RRD40 and the RRD50 are removable 4.7-inch (120-mm) compact discs. However, the media for the RRD40 are enclosed in protective self-loading carriers. The RRD40 with a SCSI interface is also available as an embedded unit. The RRD40 and RRD50 Q-bus subsystems are standard disk MSCP devices.
RX01
Console Disk (VAX Only) ![]()
On
VAX systems, the RX01 disk uses a diskette. The disk is connected
to the LSI console on the VAX-11/780, which the driver accesses
using the MTPR and MFPR privileged instructions.
For logical and virtual block I/O operations, data is accessed with one block resolution (four sectors). The sector numbers are interleaved to expedite data transfers. Logical-to-Physical Translation (RX01 and RX02) describes sector interleaving in greater detail.
For physical block I/O operations, the track, sector, and cylinder parameters describe a physical, 128-byte RX01 sector (see Disk Physical Address and Disk Function Codes). Note that the driver does not apply track-to-track skew, cylinder offset, or sector interleaving to this physical medium address.
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Figure 1 Disk Physical Address |
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RX02
Disk (VAX Only) ![]()
On VAX systems, the RX02
disk is a mass storage device that uses removable diskettes. The
RX02 supports existing single-density, RX01-compatible diskettes.
A double-density mode allows diskettes to be recorded at twice the
linear density. An entire diskette must be formatted in either single
or double density. Mixed mode diskettes are not allowed.
The RX02 is connected to the system by an RX211 controller that interfaces with the UNIBUS adapter. Up to two disk drives can be controlled by each RX211.
For logical and virtual block I/O operations, data is accessed with single block resolution (four single-density sectors or two double-density sectors). The sector numbers are interleaved to expedite data transfers. Logical-to-Physical Translation (RX01 and RX02) describes this feature in greater detail.
For physical block I/O operations, the track and sector parameters shown in Disk Physical Address describe a physical sector (128 bytes in single density; 256 bytes in double density). The driver does not apply track-to-track skew, cylinder offset, or sector interleaving to the physical medium address.
RX23
(VAX Only) ![]()
On VAX systems,
the RX23 device is a 1-inch high, flexible diskette drive that uses
3.5-inch microfloppy diskettes. The RX23 drive can access standard-
and high-density media. The following table summarizes capacities
for standard- and high-density media:
| Density | Unformatted | Formatted |
|---|---|---|
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Standard
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1.0 MB
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700 KB
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High
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2.0 MB
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1.4 MB
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The RX23 is backward compatible in that it can read 1-MB media. It can also read and write 2.0-MB double-sided, high-density (135 tracks per inch) media.
The RX23 communicates with the controller using the ST506 fixed-disk interconnect (FDI).
RX33
(VAX Only) ![]()
On VAX systems,
the RX33 is a 1.2-MB, 5.25-inch, half-height diskette drive. The
RX33 can record in either standard- or high-density mode. High-density
mode provides 1.2 MB of storage using 96 tracks per inch using double-sided,
high-density diskettes.
In standard-density mode, the RX33 drive is read- and write-compatible with single-sided, standard-density RX50 diskettes.
RX50
(VAX Only) ![]()
On VAX systems,
the RX50 dual-diskette drive stores data in fixed-length blocks
on 5.25-inch 0.8-MB, flexible diskettes using preformatted headers.
The RX50 can accommodate two diskettes simultaneously.
RZ22, RZ23, and RZ55 Disks ![]()
The RZ22 and RZ23 are 3.5-inch,
half-height SCSI drives with an average seek rate of 33 ms and an
average data transfer rate of 1.25 MB per second. The RZ22 and RZ23
have capacities of 52 MB and 104 MB, respectively.
The RZ55 is a 332-MB, 5.25-inch, full-height SCSI drive with an average access rate of 24 ms.
TU58
Magnetic Tape (DECtape II) ![]()
The TU58 is
a random-access, mass storage magnetic tape device capable of reading
and writing 256 KB per drive of data on block-addressable, preformatted
cartridges at 800 bpi. Unlike conventional magnetic tape systems,
which store information at variable positions on the tape, the TU58
stores information at fixed positions on the tape, as do magnetic
disk or floppy disk devices. Therefore, blocks of data can be placed
on tape in a random fashion, without disturbing previously recorded
data. In its physical geometry, the tape is conceptually viewed
as having one cylinder, four tracks per cylinder, and 128 sectors
per track. Each sector contains one 512-byte block.
The TU58 uses two vectors. NUMVEC=2 is required on the CONNECT command when specifying system parameters.
The TU58 interfaces with the UNIBUS adapter through a DL11-series interface device. Both the TU58 and the DL11 should be set to 9600 baud. (Because the TU58 is attached to a DL11, the user cannot directly access the TU58 registers if the TU58 is on the UNIBUS.) The TU58, which has its own controller, can access either one or two tape drives.
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