HP 3000 Manuals HP 3000 Manuals
MPE/iX Host Control for Tape Drives
by Larry Nichoalds
Commercial Systems Division
Included with this MPE/iX release is a new utility called DEVCTRL (Device
Control). DEVCTRL interfaces with the program DEVTOOL to allow both
1/2-inch and DDS tape devices to be dynamically configured to eject the
media following an application rewind/offline or close. In addition, if
you have the newly released HPC1504B or HPC1521B DDS drives or an STK
4280/4220 cartridge tape drive running HP 1.1 firmware, the data
compression mode can be enabled or disabled.
Disabling the data compression option allows for tapes to be created
which can then be read by non-compressing DDS devices. Later on, you may
enable compression mode again to create compressed tapes.
To reset options, you must run the utility again with different
configuration options.
The following table defines how each of the different tape drives work
with DEVCTRL:
-------------------------------------------------------------------------------------------
| |
| Tape Drives Data Tape Note |
| Compression Eject (1) |
| |
-------------------------------------------------------------------------------------------
| |
| HP1504B/1521B (2) Yes Yes SCSI Data Compressing |
| |
| HP1503B/1520B No Yes SCSI Non Data Compressing |
| |
| HP1502A/1512A No Yes SCSI Non Data Compressing |
| |
| HP1501A/1511A No Yes HPIB Non Data Compressing |
| |
| STK 4280/4220 Yes No With HP 1.1 FW |
| |
| HP7980S/HP7980SX No Yes SCSI 1/2-inch tape |
| |
| HP7980/HP7980XC No Yes HPIB 1/2-inch tape, see Important |
| Details note |
| |
| Other HPIB Tape NA NA 7978, 7976, 7974 |
| |
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(1) All the tape drives do not maintain the eject settings when the
system is rebooted.
(2) These tape drives do not maintain the compression settings when the
system is rebooted.
DEVCTRL can be run directly from the console, other terminal or
incorporated into a job stream.
The following defines the command-like syntax for DEVCTRL:
Syntax
DEVCTRL logical device [compression = [enable|disable|nochange]]
[eject = [enable|disable|nochange]]
Examples
To enable data compression and the eject feature for LDEV 50:
DEVCTRL 50 compression=enable eject=enable
To enable the eject feature for only LDEV 50:
DEVCTRL 50 eject=enable
The logical device number is a required field, but compression and eject
are optional and can appear in any order. If the keywords are absent the
order is interpreted as compression first and eject second. For example,
DEVCTRL 50 enable disable
would enable compression and disable the eject feature.
NOTE If you don't know the status for a tape drive (whether it's enabled
or disabled), reset it.
\ \ \ Important Details \ Please Read For this MPE/iX release, DEVCTRL
and its companion program DEVTOOL
are located in the MPEXL.TELESUP
group and account. If you need to
relocate the utility, be certain
to move only the DEVCTRL command
file. DEVCTRL expects to find the
DEVTOOL program in the
MPEXL.TELESUP group and account.
For 7980 and 7980XC, the eject
feature can be configured into the
device through the front panel
using configuration option 81.
If you use both compressing and non-compressing DDS tape drives, you may
inadvertently put a compressed tape into a non-compressing drive. The
results of this mistake vary depending on the type of non-compressing
drive the tape is placed in.
When using an HPC1503B, the following AVR message is created in response
to a compressed tape mount:
I/O error ignored during AVR. I/O status % 74.
For an HPC1300H (HPIB DDS) or an HPC1502A, no AVR error is created.
However, any attempt to access the data on the tape results in an I/O
error. For example, if you execute a RESTORE the RESTORE aborts with a
CIERR 1091.