chdev

Purpose

Use the chdev command to change the attributes of a configured tape drive or library. Use the mkdev command to configure a device.

Prerequisites

You must have the modify administrative domain's configuration right to use the chdev command.

Syntax

Syntax 1

Use the following syntax to reconfigure a tape drive.

chdev::=

chd•ev [ --attach/-a aspec[,aspec]... ]
[ --addattach/-A aspec[,aspec]... ] [ --rmattach/-R aspec[,aspec]... ]
[ --inservice/-o | --notinservice/-O ] [ --wwn/-W wwn ]
[ --library/-l devicename ] [ --dte/-d dte ]
[ --blockingfactor/-f bf ] [ --maxblockingfactor/-F maxbf ]
[ --automount/-m { yes | no }  ] [ --erate/-e erate ]
[ --current/-T se-spec ] [ --uselist/-u se-range ]
[ --usage/-U duration ] [ --queryfreq/-q queryfrequency ]
[ --serial/-N serial-number ] [ --model/-L model-name ]
devicename ...

Syntax 2

Use the following syntax to reconfigure a tape library.

chdev::=

chd•ev [ --attach/-a aspec[,aspec]... ]
[ --addattach/-A aspec[,aspec]... ] [ --rmattach/-R aspec[,aspec]... ]
[ --inservice/-o | --notinservice/-O ] [ --wwn/-W wwn ]
[ --autoclean/-C { yes | no }  ] [ --cleanemptiest/-E { yes | no }  ]
[ --cleaninterval/-i { duration | off } ]
[ --barcodereader/-B { yes | no | default } ]
[ --barcodesrequired/-b { yes | no }  ] [ --unloadrequired/-Q { yes | no }  ]
[ --serial/-N serial-number ] [ --model/-L model-name ]
devicename ...

Semantics

The following options enable you to reconfigure a tape drive or library. Refer to "mkdev" for descriptions of options not included in this section.

--addattach/-A aspec ...

Adds a device attachment for a tape drive or library. Refer to "aspec" for a description of the aspec placeholder.

--rmattach/-R aspec ...

Removes a device attachment for a tape drive or library. Refer to "aspec" for a description of the aspec placeholder.

--usage/-U duration

Specifies the amount of time a drive has been used since it was last cleaned. Refer to "duration" for a description of the duration placeholder.

The mkdev command enables you to request a cleaning cycle for a specific interval. Specify the --usage option on chdev to initialize the configured interval to reflect drive usage since the last cleaning.

devicename ...

Specifies the name of the library or tape drive to be reconfigured. Refer to "devicename" for the rules governing device names.

Examples

Example 2-18 reconfigures tape drive tape1 in library lib1. The chdev command specifies the following:

• The tape drive is in service.

• The error rate is 16 (the default is 8).

• The blocking factor is 256, which means that obtool writes blocks of size 128K.

• Tapes can be automounted.

Note that the command line has been reformatted to fit on the page.

ob> lsdev --long tape1
tape1:
    Device type:            tape (virtual)
    Model:                  [none]
    Serial number:          [none]
    In service:             yes
    Library:                lib1
    DTE:                    1
    Automount:              yes
    Error rate:             8
    Query frequency:        [undetermined]
    Debug mode:             no
    Blocking factor:        (default)
    Max blocking factor:    (default)
    Current tape:           4
    Use list:               all
    Drive usage:            33 seconds
    Cleaning required:      no
    UUID:                   42e073da-5a39-1028-92bf-000cf1d9be50
    Attachment 1:
        Host:               brhost3
        Raw device:         /dev/tape1
ob> chdev --type tape --erate 16 --blockingfactor 256 
--maxblockingfactor 256 tape1

Example 2-19 reconfigures a tape library called lib1. The chdev command specifies the following:

• The tape library is in service.

• There is no barcode reader.

• The interval between automatic cleaning cycles is 30 hours.

• obtool should use the fullest cleaning tape for cleaning.

Note that the command line has been reformatted to fit on the page.

ob> lsdev --long --nohierarchy lib1
lib1:
    Device type:            library
    Model:                  [none]
    Serial number:          [none]
    In service:             yes
    Debug mode:             no
    Barcode reader:         default (hardware-selected)
    Barcodes required:      no
    Auto clean:             no
    Clean interval:         (not set)
    Clean using emptiest:   no
    UUID:                   f088f234-8d46-1027-90e1-000cf1d9be50
    Attachment 1:
        Host:               brhost3
        Raw device:         /dev/lib1
ob> chdev --type library --inservice --barcodereader no --barcodesrequired no
--autoclean yes --cleanemptiest no --cleaninterval 30hours lib1
ob> lsdev --long --nohierarchy lib1
lib1:
    Device type:            library
    Model:                  [none]
    Serial number:          [none]
    In service:             yes
    Debug mode:             no
    Barcode reader:         no
    Barcodes required:      no
    Auto clean:             yes
    Clean interval:         30hours
    Clean using emptiest:   yes
    UUID:                   f088f234-8d46-1027-90e1-000cf1d9be50
    Attachment 1:
        Host:               brhost3
        Raw device:         /dev/lib1