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Configuring drives with persistent naming for IBM devices on Linux



Learn how to use persistent names to configure IBM libraries and tape drives for the Tivoli Storage Manager server running on Linux.

Resolving The Problem

The IBM Tape Device Drivers Installation and User's Guide has detailed information on configuration persistent naming with the IBM device driver on Linux. The information is provided under chapter 4, titled : "Linux Tape and Medium Changer device driver". Refer to section titled "Special files", sub-section titled "Persistent Naming Support". Persistent naming is configured using Linux udev rules. An example on how to configure the persistent name on Linux is provided via technote # 1459487.

Once persistent is configured, the goal is to identify the WWN or the serial number of the device and its name so this information can be used when defining paths on the Tivoli Storage Manager server. The persistent names associated to the IBM devices can be queried using the information from the udev file and the ls command. For example :

# more /etc/udev/rules.d/98-lin_tape.rules
KERNEL=="IBMtape*[!n]", SYSFS{serial_num}=="1110058875",SYMLINK="lin_tape/by-id/tapedrive_1110058875"
KERNEL=="IBMtape*[!n]", SYSFS{serial_num}=="1110027758",SYMLINK="lin_tape/by-id/tapedrive_1110027758"
KERNEL=="IBMtape*[!n]", SYSFS{serial_num}=="4966383000",SYMLINK="lin_tape/by-id/tapedrive_4966383000"
KERNEL=="IBMtape*[!n]", SYSFS{serial_num}=="4966383001",SYMLINK="lin_tape/by-id/tapedrive_4966383001"
KERNEL=="IBMchanger*[!n]", SYSFS{serial_num}=="0000000103640401",SYMLINK="lin_tape/by-id/changer_0000000103640401"
KERNEL=="IBMchanger*[!n]", SYSFS{serial_num}=="0049663839990402",SYMLINK="lin_tape/by-id/changer_0049663839990402"

The above output shows that the "/dev/lin_tape/by-id/" prefix is used to configure the persistent names. Use the "ls" command to find the device names. For example :

# ls -la /dev/lin_tape/by-id
lrwxrwxrwx 1 root root 17 Feb 11 09:52 changer_0000000103640401 -> ../../IBMchanger0
lrwxrwxrwx 1 root root 17 Feb 11 09:52 changer_0049663839990402 -> ../../IBMchanger1
lrwxrwxrwx 1 root root 14 Feb 11 09:52 tapedrive_1110027758 -> ../../IBMtape1
lrwxrwxrwx 1 root root 14 Feb 11 09:52 tapedrive_1110058875 -> ../../IBMtape0
lrwxrwxrwx 1 root root 14 Feb 11 09:52 tapedrive_4966383000 -> ../../IBMtape2
lrwxrwxrwx 1 root root 14 Feb 11 09:52 tapedrive_4966383001 -> ../../IBMtape3

The above output shows that device /dev/lin_tape/by-id/tapedrive_1110058875 is the persistent device name associated to device /dev/IBMtape0. The persistent name includes the serial number in its name. In this case, the serial number is 1110058875.

The serial number of the device can also be identified with the IBM Tape Diagnostic Tool using the itdt inquiry command. For example :

# ./itdt -f /dev/IBMtape0 inquiry 80
Issuing inquiry for page 0x80...
Inquiry Page 0x80, Length 14

0 1 2 3 4 5 6 7 8 9 A B C D E F 0123456789ABCDEF
0000 - 0180 000A 3131 3130 3035 3838 3735 [....1110058875 ]
Exit with code: 0

The above output shows that the serial number of device /dev/IBMtape0 is 1110058875.

Once the persistent name and its associated serial number have been identified, this information can be used to define the DRIVE path with the appropriate persistent name. Run the QUERY DRIVE F=D command on the Tivoli Storage Manager. For example :

tsm: MYTSM>q drive f=d
Library Name: 3584LIB
Drive Name: 3584-DRV1
Device Type: LTO
WWN: 5005076300026C01
Serial Number: 1110058875

In this case, drive 3584-DRV1 is the drive with serial number 1110058875. When defining a drive path for storage agent or library client for library sharing, use the persistent name when defining the drive path. For example :

define path MYAGENT 3584-DRV1 srct=server destt=drive library=3584LIB device=/dev/lin_tape/by-id/tapedrive_1110058875

[{"Product":{"code":"SSGSG7","label":"Tivoli Storage Manager"},"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Component":"Server","Platform":[{"code":"PF016","label":"Linux"}],"Version":"All Supported Versions","Edition":"","Line of Business":{"code":"LOB26","label":"Storage"}}]

Document Information

Modified date:
17 June 2018