T-ATT
Attaches a tape unit list to the default channel for the local process and optionally assigns tape parameters to that channel.
Note
To set up named channels, use ASSIGN.
Command Class
TCL-I command.
Syntax
T-ATT {unit-list {SIZE=recordSize} {DEN=density} {BUFF=buffers} {LABEL=labelType}}
Syntax Elements
unit-list The number(s) of the tape unit(s) to be used, separated by commas. The default, if omitted, is unit 1. However, unit-list must be specified explicitly if any other parameters are specified.
recordSize The tape record size in bytes. Default if omitted, 8000.
Note
The record size used with encrypted tape devices must be a multiple of 8.
density The tape density. This can be 800, 1600, 3200 or 6250 bpi, depending on your system, or 24, 120, 150, 320 or 525 QIC format for quarter inch cartridge tape units. The density determines the tape device used as specified in the database config file. For details, refer to Tape Definitions.
The density parameter is optional. The default is defined in the database config file.
When a density has been selected for a unit, it remains in force for any subsequent assignments until the density is redefined or the assignment is destroyed by tape detachment or log off.
buffer The number of tape buffers, in the range 1 to 10. The default is 2. The size of each buffer is equal to the record size. Most installations use the default value.
labelType The type of tape label to be written; one of the following:
2 SMA standard 80-byte label (default).
Note
If the record size is larger than 32Kbytes, a modified type 2 label is used. See Tape Labels for details.
1 Reality 50-byte label. Allows you to write tapes that can be read on early proprietary versions of Reality.
0 No label (use of this type is not recommended).
In read operations, the label type is automatically set to that found on the tape, and so this parameter does not need to be specified.
Options
L Leaves tapes loaded until all tapes have been written once. This allows a save to be carried out immediately after a restore without operator intervention.
If the tape system attempts to wrap around and write on the first tape, all units are unloaded.
Comment
Unspecified parameters are reset to their default values.
The tape speed is determined by the process being carried out and cannot be independently selected. For example, the tape speed is high for file and account saves whereas a lower speed is used for tape dumps.
Before using T-ATT, you must load the tape and switch the unit(s) on-line, otherwise the assignment may fail.
The tape unit attached and the density/QIC parameter selected is determined by the tape configuration defined in the database config file. For details, refer to Tape Definitions.
Messages
If a unit has already been assigned to another channel, the following message is displayed:
Device tape n assigned to this line, but for another channel
If you attempt to perform a tape operation before attaching the tape drive the following message is displayed:
[1129] No such tape assignment exists
If you attempt to attach a tape that is already assigned to another user, the following message is displayed:
Device(s) tape n now assigned to channel m
If you attempt to attach a tape device number which is not configured on your database, the following message is displayed:
Device Tape n not on this system
Examples
:T-ATT
[1021] DEVICE(S) TAPE 1 NOW ASSIGNED,
RECORD SIZE = 8000 DENSITY = 1600
No parameters are specified, so tape unit 1 is attached with the default settings.
:T-ATT 2 SIZE = 2048
[1201] DEVICE(S) TAPE 2 NOW ASSIGNED,
RECORD SIZE = 2048 DENSITY = 1600
Tape unit 2 is attached with a record size of 2048 bytes.