Forum Discussion

Ewe's avatar
Ewe
Level 3
5 years ago

What do you mean RESET PATH / MISSING PATH ERROR

Hello,  I've some issue with my library especially with a drive.  I don't understand why I'm loose a path on onen drive. The others still working correctly.  By consequently a tape still lock in t...
8.1.2
Linux
  • Nicolai's avatar
    Nicolai
    5 years ago

    You are correct, if OS cannot see the tape drive, no device driver path are created.

    Once you get a change to talk to the FC admin, ask him to check if he/she can see 5 drives in SAN fabric. If yes, check SAN zoning include all 5 drives.

    Depending on FC HBA vendor, each company provide low level utilities that let you see, what the FC card can see, without going through the OS layer. For Qlogic card, this utility is called SANSurfer. It won't repair anything, but it will help you in troubleshooting the issue, by providing certainty about drive being visible to the host or not.

Nicolai's avatar
Nicolai
Moderator
5 years ago

From the screen dump provided, it looks like either the tape drive drop off the fibre channel bus. A device driver point to a tape drive, if either the tape drive drop off because of FC issues, or a non existing path is used, you will get MISSING_PATH. That is Netbackup way of saying "the path to the tape drive is missing".

My advice:

Check the scan command in /usr/openv/volmgr/scan before configuring tape devices. Does the command show the tape devices you expect ?

Consider to call in hardware vendor

Check relevant log for Fibre Channel issues or SCSI sense to narrow down issue.

  • Ewe's avatar
    Ewe
    Level 3
    5 years ago

    Thank you for your feedback

    On the header we can see the 4 drives

    It seems that the drive 4 is more visible, there are anymore path. 

    We can check the information somewhere? We can make log?
    I can do something for uplink this drive ?

    scan
    ************************************************************
    *********************** SDT_TAPE ************************
    *********************** SDT_CHANGER ************************
    ************************************************************
    ------------------------------------------------------------
    Device Name : "/dev/sg10"
    Passthru Name: "/dev/sg10"
    Volume Header: ""
    Port: -1; Bus: -1; Target: -1; LUN: -1
    Inquiry : "HP MSL6480 5.70"
    Vendor ID : "HP "
    Product ID : "MSL6480 "
    Product Rev: "5.70"
    Serial Number: "DEC451067F_LL02"
    WWN : ""
    WWN Id Type : 0
    Device Identifier: "HP MSL6480 DEC451067F_LL02"
    Device Type : SDT_CHANGER
    NetBackup Robot Type: 8
    Removable : Yes
    Device Supports: SCSI-5
    Number of Drives : 5
    Number of Slots : 70
    Number of Media Access Ports: 10
    Drive 1 Serial Number : "8026DD210D"
    Drive 2 Serial Number : "8026DD2117"
    Drive 3 Serial Number : "8026DD2121"
    Drive 4 Serial Number : "8026DD212B"
    Drive 5 Serial Number : "8026DD213F"
    Flags : 0x0
    Reason: 0x0
    ------------------------------------------------------------
    Device Name : "/dev/tape/by-path/pci-0000:24:00.0-fc-0x5001438026dd210e-lun-0-n st"
    Passthru Name: "/dev/sg9"
    Volume Header: ""
    Port: -1; Bus: -1; Target: -1; LUN: -1
    Inquiry : "HP Ultrium 6-SCSI 25MW"
    Vendor ID : "HP "
    Product ID : "Ultrium 6-SCSI "
    Product Rev: "25MW"
    Serial Number: "8026DD210D"
    WWN : ""
    WWN Id Type : 0
    Device Identifier: ""
    Device Type : SDT_TAPE
    NetBackup Drive Type: 16
    Removable : Yes
    Device Supports: SCSI-6
    Flags : 0x0
    Reason: 0x0
    ------------------------------------------------------------
    Device Name : "/dev/tape/by-path/pci-0000:24:00.1-fc-0x5001438026dd2118-lun-0-n st"
    Passthru Name: "/dev/sg3"
    Volume Header: ""
    Port: -1; Bus: -1; Target: -1; LUN: -1
    Inquiry : "HP Ultrium 6-SCSI 25MW"
    Vendor ID : "HP "
    Product ID : "Ultrium 6-SCSI "
    Product Rev: "25MW"
    Serial Number: "8026DD2117"
    WWN : ""
    WWN Id Type : 0
    Device Identifier: ""
    Device Type : SDT_TAPE
    NetBackup Drive Type: 16
    Removable : Yes
    Device Supports: SCSI-6
    Flags : 0x0
    Reason: 0x0
    ------------------------------------------------------------
    Device Name : "/dev/tape/by-path/pci-0000:24:00.1-fc-0x5001438026dd2140-lun-0-n st"
    Passthru Name: "/dev/sg5"
    Volume Header: ""
    Port: -1; Bus: -1; Target: -1; LUN: -1
    Inquiry : "HP Ultrium 6-SCSI 25GW"
    Vendor ID : "HP "
    Product ID : "Ultrium 6-SCSI "
    Product Rev: "25GW"
    Serial Number: "8026DD213F"
    WWN : ""
    WWN Id Type : 0
    Device Identifier: ""
    Device Type : SDT_TAPE
    NetBackup Drive Type: 16
    Removable : Yes
    Device Supports: SCSI-6
    Flags : 0x0
    Reason: 0x0
    ------------------------------------------------------------
    Device Name : "/dev/tape/by-path/pci-0000:24:00.0-fc-0x5001438026dd2122-lun-0-n st"
    Passthru Name: "/dev/sg8"
    Volume Header: ""
    Port: -1; Bus: -1; Target: -1; LUN: -1
    Inquiry : "HP Ultrium 6-SCSI 25GW"
    Vendor ID : "HP "
    Product ID : "Ultrium 6-SCSI "
    Product Rev: "25GW"
    Serial Number: "8026DD2121"
    WWN : ""
    WWN Id Type : 0
    Device Identifier: ""
    Device Type : SDT_TAPE
    NetBackup Drive Type: 16
    Removable : Yes
    Device Supports: SCSI-6
    Flags : 0x0
    Reason: 0x0

     

     

    • Nicolai's avatar
      Nicolai
      Moderator
      5 years ago

      OK - Robot can see 5 drives, but OS can only access 4 drives.

      Drive 4 with serial nimber "8026DD212B" isn't listed.

      Check:

      Hardware (tape drive is powered on, OK seen from the robot)
      Configuration of the tape library - no partitions or like.

      If connected by fibre channel:
      Fibre Channel Name server can see all 5 drives
      Verify zonning is correct (my guess the fault is here)

      /Nicolai

      • Ewe's avatar
        Ewe
        Level 3
        5 years ago

        Ok thank you, 

        From web interface of my library it looks good. The drive is up and running. 
        I'll contact HP support to send the robot logs. Maybe they'll see something.

        I'm looking for the path "/dev/tape/by-path/pci-0000..." of this missing drive in media server but there are nothing. This path doesn't exist.

        By consequently, i suppose my system doesn't see the drive. That explain why Netbackup can't turn up the path  

        In /var/log/message or dmesg i don't see anything, no error.  

        Do you think I can check something on the other side of the system?

        About FC configuration I need ask teaming who manage that