IBM TS2340 User Guide - Page 413

Disable and Enable Primary and Alternate Paths (Control Path Failover), Querying Primary and Alternate Path Configuration (Data Path Failover)

Page 413 highlights

Linux - Tape Utility Program (IBMtapeutil) Disable and Enable Primary and Alternate Paths (Control Path Failover) Once you load the lin_tape device driver with the alternate_pathing parameter to be ON, by default, all the available paths for a physical device are enabled. If for some maintenance reason you need to disable a path and do not want to fail over to this path, you can run the following commands: v IBMtapeutil -f /dev/IBMchangerx path (to know what number of this path is) v IBMtapeutil -f /dev/IBMchangerx disablepath number (where: number is the number of the path you want to disable) v IBMtapeutil -f /dev/IBMchangerx path (to make sure the path is labeled as ″disabled″) Correspondingly, in the /proc/scsi/IBMchanger file, the disabled path is listed as ″Disabled″ under the ″FO Path″ column. To enable a path from a disabled state, you can run the following command: v IBMtapeutil -f /dev/IBMchangerx enablepath number (where: number is the number of the path you want to enable) Querying Primary and Alternate Path Configuration (Data Path Failover) You can display the primary and alternate path configuration for all devices by reading the /proc/scsi/IBMtape file.You can also display the primary and alternate path configuration for any device by running the following command: >IBMtapeutil -f /dev/IBMtapex path (IBMtapex is the logical name of any device) This command shows specific information for the primary path and all alternate paths, such as the logical name of the device, the attached host bus adapter, the channel id, the target id, the logical unit number under the target, the current enabled status, and how many paths are configured for the device. Once you load the lin_tape device driver with the alternate_pathing parameter to be ON, by default, all the available paths for a physical device are enabled. If for some maintenance reason you need to disable a path and do not want to fail over to this path, you can run the following commands: v IBMtapeutil -f /dev/IBMchangerx path (to know what number of this path is) v IBMtapeutil -f /dev/IBMchangerx disablepath number (where: number is the number of the path you want to disable) v IBMtapeutil -f /dev/IBMchangerx path (to make sure the path is labeled as ″disabled″) Correspondingly, in the /proc/scsi/IBMchanger file, the disabled path is listed as ″Disabled″ under the ″FO Path″ column. To enable a path from a disabled state, you can run the following command: v IBMtapeutil -f /dev/IBMchangerx enablepath number (where: number is the number of the path you want to enable) Appendix D. Tape Utility Programs 395

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Disable and Enable Primary and Alternate Paths (Control Path
Failover)
Once you load the lin_tape device driver with the
alternate_pathing
parameter to be
ON, by default, all the available paths for a physical device are enabled. If for
some maintenance reason you need to disable a path and do not want to fail over
to this path, you can run the following commands:
v
IBMtapeutil -f /dev/IBMchangerx
path (to know what number of this path is)
v
IBMtapeutil -f /dev/IBMchangerx
disablepath
number
(where:
number
is the number
of the path you want to disable)
v
IBMtapeutil -f /dev/IBMchangerx
path (to make sure the path is labeled as
disabled
)
Correspondingly, in the
/proc/scsi/IBMchanger
file, the disabled path is listed as
Disabled
under the
FO Path
column.
To enable a path from a disabled state, you can run the following command:
v
IBMtapeutil -f /dev/IBMchangerx
enablepath
number
(where:
number
is the number
of the path you want to enable)
Querying Primary and Alternate Path Configuration (Data Path
Failover)
You can display the primary and alternate path configuration for all devices by
reading the
/proc/scsi/IBMtape
file.You can also display the primary and alternate
path configuration for any device by running the following command:
>IBMtapeutil -f /dev/IBMtapex path (IBMtapex is the logical name of any device)
This command shows specific information for the primary path and all alternate
paths, such as the logical name of the device, the attached host bus adapter, the
channel id, the target id, the logical unit number under the target, the current
enabled status, and how many paths are configured for the device.
Once you load the lin_tape device driver with the
alternate_pathing
parameter to be
ON, by default, all the available paths for a physical device are enabled. If for
some maintenance reason you need to disable a path and do not want to fail over
to this path, you can run the following commands:
v
IBMtapeutil -f /dev/IBMchangerx
path (to know what number of this path is)
v
IBMtapeutil -f /dev/IBMchangerx
disablepath
number
(where:
number
is the number
of the path you want to disable)
v
IBMtapeutil -f /dev/IBMchangerx
path (to make sure the path is labeled as
disabled
)
Correspondingly, in the
/proc/scsi/IBMchanger
file, the disabled path is listed as
Disabled
under the
FO Path
column.
To enable a path from a disabled state, you can run the following command:
v
IBMtapeutil -f /dev/IBMchangerx
enablepath
number
(where:
number
is the number
of the path you want to enable)
Linux - Tape Utility Program (IBMtapeutil)
Appendix D. Tape Utility Programs
395