chg-device

chg-device


tape label Index Level set-8mm
Syntax chg-device device.number option=value { option=value ... }
chg-device ?
Category Tape
Type Verb
Description changes a tape device.

Devices which can be used as tapes are listed by the "list-device" command. Some characteristics can be changed to either modify the behavior of a device or to replace a device by another one.

The changes made with this command are not permanent and are lost when the virtual machine is rebooted. If no option is specified, the current value is retained. The following options and values are recognized:

name=newname

This specifies a new device name. Since this is likely to completely change the device, all other options should be specified as well. Spaces are not allowed. The length of the new name cannot exceed 63 characters.

type=[floppy|halfinch|8mm|sct]

Specifies the type of device.

density=[360K|1.2M|1.44M|pseudo]

This specifies the density for a floppy. "pseudo" indicates an 'infinite' density device, such as pseudo floppy on hard disk.

density=[1600|3200|6250]

Specifies the density for a half inch device. This field is essentially for information purposes, since, on most Unix implementations, the density of the drive is encoded in the device name (as a suffix, for instance).

density=[low|standard|high]

Specifies the density for a SCT. This field is essentially for information purposes, since, on most Unix implementations, the density of the drive is encoded in the device name (as a suffix, for instance).

label=[80|512]

Specifies the label block size. Valid for 8mm tapes only. The D3 label is always 80 bytes long, but some D3 implementations write it in a 80 byte block, while D3 writes it in a 512 byte block. To be able to exchange 8mm tapes between systems, it might be necessary to change this option.

blksize=default block size

Specifies the default block size. Usually, this is 16384 for Native systems, and 512 for hosted Unix systems.

volsz=volume size

Specifies the number of 1k (1024 byte) blocks to write to a compressed pseudo tape before cascading to a new file.  NOTE: this option is only valid for compressed pseudo tape devices.
Options
See Also list-device set-device config tape t-select t-stat chg-device
Example chg-device ?
USAGE: CHG-DEVICE devnum option=value {option=value ..}  {(option}
options:
name=newname
type=[ floppy | halfinch | 8mm | sct ]
density=[360K|1.2M|1.44M|pseudo] (floppy)
       [ 1600 | 3200 |6250 ]  (1/2 inch)
       [ low | standard | high ]   (sct)
label=[ 80 | 512 ]             (8mm only)
blksize=newblksize
Displays the help.

chg-device 7 name=/tmp/pseudotp
Changes the name of the Unix file or pipe used as a pseudo tape.
Warnings Chg-device must be used before the device is attached.  Failure to do this will result in an error message.
Compatibility D3 7.0 AP
tape label Index Level set-8mm