EXCHANGE, INITIALIZE
*Conan The Librarian (sorry for the slow response - running on an old VAX)
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VMS Help EXCHANGE, INITIALIZE *Conan The Librarian (sorry for the slow response - running on an old VAX) |
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Formats and writes a label on a foreign mass storage volume.
For directory-structured devices, the device directory is also
initialized.
Format
INITIALIZE device-name [volume-label]
INITIALIZE/CREATE file-name [volume-label]
| 1 - Parameters |
device-name
Specifies the name of the device on which the volume to be
initialized is physically mounted.
The device name can also refer to the name of a mounted virtual
device to be reinitialized.
file-name
For INITIALIZE/CREATE, file-name refers to the name of a file to
be created and initialized as a virtual device.
volume-label
Specifies the identification to be written onto the volume header
for RT-11 volumes only. The volume label can contain up to a
maximum of 12 alphanumeric characters. The default is OpenVMS
Exchange. Use quotation marks to specify a volume label with
lowercase letters.
| 2 - Description |
The EXCHANGE command INITIALIZE erases all files from a volume.
After initialization, the volume directory contains no files.
DOS-11 magnetic tapes and RT-11 block-addressable devices can be
initialized.
The device must be mounted with the /FOREIGN qualifier.
| 3 - Qualifiers |
3.1 - /ALLOCATION
/ALLOCATION=n
Specifies the allocation of a new virtual device file in terms
of 512-byte blocks. The allocation specified is the number you
entered as n. If you do not specify the /ALLOCATION qualifier
when you create a new virtual device file, the default allocation
is 494 blocks, the size of a single-density diskette. The maximum
allocation is 65,536 blocks.
A virtual device file is usually the size of a standard device
supported by both RT-11 and OpenVMS. These sizes are as follows:
Device Blocks
TU58 512
RX01 494
RX02 494 (single density)
RX50 800
RX02 988 (double density)
RX33 2400
RL02 20480
RK06 27126
RK07 53790
You can also use the /ALLOCATION qualifier to reduce the size
of a physical device. For example, if you want to prepare
an RL02 disk but have only an RK07 device available, you can
initialize the RK07 to a volume of 20,480 blocks. When the RL02
is available, you can transfer the files to the RL02 knowing they
will fit on the smaller device.
3.2 - /BADBLOCKS
/BADBLOCKS[=RETAIN]
Performs a bad block scan of the volume before initialization. A
file named FILE.BAD is created on top of each bad block or group
of bad blocks encountered on the device, preventing any future
use of the bad areas.
If a bad block is found in either the boot block or the volume
directory, the volume is not usable and EXCHANGE displays
an error message. If the bad block is in a directory segment
other than the first, you might be able to use the volume by
reinitializing it with a smaller number of segments (see the
/SEGMENTS qualifier description).
If you specify /BADBLOCKS=RETAIN, EXCHANGE uses the device's
existing bad block information, instead of performing a bad block
scan. Therefore, initializing takes less time. If you do not
specify RETAIN, EXCHANGE writes a pattern on each block of the
volume, then reads each block to verify that the block is usable.
EXCHANGE prints a list of the bad blocks found on the device.
RK06, RK07, and RL02 disk volumes support bad block replacement.
Therefore, Compaq recommends that you use the /REPLACE=RETAIN
qualifier for these volumes. If you use the /BADBLOCKS qualifier
with a volume initializied previously with the /REPLACE
qualifier, EXCHANGE deletes the bad block replacement table and
performs a new bad block scan. If you use /BADBLOCKS=RETAIN with
such a volume, EXCHANGE uses the FILE.BAD files created during
the volume initialization.
3.3 - /CREATE
Specifies that a virtual device is to be created and initialized.
The specification is a file name; if a file type is not given,
EXCHANGE applies the default type of DSK.
3.4 - /DENSITY
/DENSITY=density-value
Specifies, for magnetic tape volumes, the density in bytes per
inch (bpi) at which the tape is to be written.
For magnetic tape volumes, the density value specified can be 800
or 1600, as long as the density is supported by the magnetic tape
drive. If you do not specify a density value for a blank tape,
the system uses a default of the lowest density supported by the
tape drive.
For the RX02 dual-density diskette drive, use the DCL command
INITIALIZE/DENSITY=SINGLE or INITIALIZE/DENSITY=DOUBLE to
reformat the diskettes to a different density; then use the
EXCHANGE command INITIALIZE to create the RT-11 directory
structure.
NOTE
Diskettes formatted in double density cannot be read or
written by the console block storage device (an RX01 drive)
of a VAX-11/780 until they have been reformatted in single
density.
3.5 - /EXTRA_WORDS
/EXTRA_WORDS=n
Specifies, for RT-11 volumes, the number of extra words to add
to each directory entry, in addition to the required seven words.
The ability to increase the length of directory entries is useful
for some RT-11 applications. Increasing the size of the directory
entries reduces the number of entries that fit in each directory
segment.
3.6 - /MESSAGE
/MESSAGE
/NOMESSAGE
Controls whether or not EXCHANGE displays a message that the
volume was initialized. The default is determined by the /MESSAGE
qualifier entered with the EXCHANGE command when EXCHANGE was
activated.
3.7 - /REPLACE
/REPLACE=RETAIN
Retains, when an RT-11 volume is initialized, the bad block
replacement table and any existing FILE.BAD files.
The RETAIN option is required; EXCHANGE cannot build a
replacement table for a volume. The RT-11 system builds and
uses the table based on specific hardware error conditions. The
OpenVMS I/O system is different, and cannot be relied upon to
generate exactly the same error conditions. Therefore, it is not
possible for EXCHANGE to generate the same replacement table that
would be generated by RT-11.
If no replacement table is present, the qualifier /REPLACE=RETAIN
is equivalent to /BADBLOCKS=RETAIN.
3.8 - /SEGMENTS
/SEGMENTS=n
Defines, for RT-11 volumes, the number of 2-block directory
segments to allocate for the directory. The number of segments
in the directory establishes the number of files that can be
stored on a device. The system allows a maximum of 72 files
per directory segment and 31 directory segments per device. The
argument n represents the number of segments; the valid range for
n is from 1 to 31 (decimal). The default values for n depend on
the device type, as follows:
Device Segments
TU58 1
RX01 1
RX02 1 (single density)
RX02 4 (double density)
RX50 4
RX33 16
RL02 16
RK06 16
RK07 31
3.9 - /VOLUME_FORMAT
/VOLUME_FORMAT=option
Defines the physical format of the volume to be processed.
The EXCHANGE command INITIALIZE is not valid for Files-11
devices.
| 4 - Examples |
1.$ MOUNT/FOREIGN DLA2:
%MOUNT-I-MOUNTED, mounted on DLA2
$ EXCHANGE
EXCHANGE> INITIALIZE DLA2:
%EXCHANGE-S-INITIALIZED, the RT-11 volume _DLA2: has been initialized
The command in this example initializes the volume mounted on
the RL02 drive DLA2. Since DLA2 is a block-addressable device
mounted with the /FOREIGN qualifier, RT-11 is the default
format. EXCHANGE physically scans all blocks of the volume,
builds a bad block replacement table, and displays a message
indicating that it failed to turn up any bad blocks.
2.EXCHANGE> INITIALIZE MTA0:/DENSITY=1600
The command in this example initializes the DOS-11 magnetic
tape volume loaded on MTA0. The density is specified as 1600
bpi; the default would have been 800 bpi for an MT drive.
3.EXCHANGE> INITIALIZE/CREATE/ALLOCATION=1000 VIRTUAL
%EXCHANGE-S-INITIALIZED, the RT-11 volume DRB0:[LOGIN]VIRTUAL.DSK
has been initialized
The command in this example creates a virtual device with an
allocation of 1000 blocks in the directory [LOGIN] on DRB0.
EXCHANGE applies the default file type DSK.
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