IBM Support

IT29844: "VSNAP DISK SHOW" MAY DISPLAY INCORRECT INFORMATION ESPECIALLY WHEN IT COMES TO MULTIPATH DISKS

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APAR status

  • Closed as program error.

Error description

  • "vsnap disk show" may display incorrect information especially
    when it comes to multipath disks. For example, after some new
    disks are mapped to vSnap and rescan is run, the NAME of an
    existing vSnap disk is changed and value of "USED AS" is changed
    from vsnap_pool to unused. Here is an example:
    
    - Before adding disks, one vsnap disk device was /dev/dm-10:
    300050773808300d0900000000000001b | MPATH | IBM   | 2145 |
    10.00TB | vsnap_pool | /dev/dm-9
    
    - After adding disks, the same device becomes /dev/dm-8 and
    USED AS is changed to unused incorrectly:
    300050773808300d0900000000000001b | MPATH | IBM   | 2145 |
    10.00TB  | unused            | /dev/dm-8
    
    This may also affect the vlaues of "DISKS IN POOL" in "vnsap
    pool show". Pleae note that the information in "vsnap disk
    show" and "vsnap pool show" is just for display purposes and it
    is not used by Spectrum Protect Plus for the purpose of backup
    and restore jobs, so it does not affect functionality.
    

Local fix

  • 1/ Identify the UUIDs in the "zpool status -D" command
    
    2/ Map the SERIAL value with UUID and identify the sdx and
    /dev/dm-x values in the below command:
    
    lsblk -o NAME,KNAME,TYPE,SIZE,VENDOR,MODEL,SERIAL
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * IBM Spectrum Protect Plus level 10.1.3 and 10.1.4.           *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Apply fixing level when available. This problem is currently *
    * projected to be fixed in IBM Spectrum Protect Plus levels    *
    * 10.1.4.222 and 10.1.5. Note that this is subject to change   *
    * at the discretion of IBM.                                    *
    ****************************************************************
    

Problem conclusion

  • vSnap collects disk information by scanning the directory
    /dev/disk/by-id which contains device links generated by udev.
    Due to incorrect parsing of multipath links (dm-uuid-*), the
    disk information collected for multipath devices could be
    inaccurate. The problem has been resolved by improving the disk
    scanning logic that now uses lsblk to collect disk information.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT29844

  • Reported component name

    SP PLUS

  • Reported component ID

    5737SPLUS

  • Reported release

    A13

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2019-07-26

  • Closed date

    2019-09-06

  • Last modified date

    2019-09-06

  • APAR is sysrouted FROM one or more of the following:

  • APAR is sysrouted TO one or more of the following:

Fix information

  • Fixed component name

    SP PLUS

  • Fixed component ID

    5737SPLUS

Applicable component levels

[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSNQFQ","label":"IBM Spectrum Protect Plus"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"A13","Line of Business":{"code":"LOB26","label":"Storage"}}]

Document Information

Modified date:
30 January 2024