15.00 - Chapter 32 Verify Pdisks (verify_pdisks) - Teradata Database

Teradata Database Utilities

Product
Teradata Database
Release Number
15.00
Content Type
Configuration
Publication ID
B035-1102-015K
Language
English (United States)
Last Update
2018-09-25

The Verify Pdisks utility, verify_pdisks, is used to verify the pdisks on the system are accessible and are mapped correctly.

Verify Pdisks reads each pdisk storage device on the node from which it was run and determines the TVS system and disk IDs associated with that device. If the IDs differ from those specified in the Vconfig GDO (globally distributed object that stores configuration settings), or if the attempt to read the pdisk device fails, verify_pdisks returns an error with information about the nature of the problem.

This utility can be run at any time regardless of the state of the PDE or Teradata Database.

Scenarios Runs From

  • Database Window or comparable interface to the Teradata Database console subsystem, such as cnsterm
  • Linux command line
  • To start Verify Pdisks, type verify_pdisks at the command prompt. For general information on starting the utilities from different interfaces, see Appendix B: “Starting the Utilities”

    Scenarios Syntax

     

    Syntax element

    Description

    -v

    Provides a detailed (verbose) description of verify_pdisks activity.

    -h

    (Help mode) Displays usage.

    -?

    (Help mode) Displays usage.

    Note: If no options are specified, Verify Pdisks reports any errors and summarizes the number of errors detected. If no errors are detected, Verify Pdisks reports that all pdisks on the current node are verified.

    Scenarios When to Run Verify Pdisks

    Verify Pdisks should be run any time you suspect that the database is unable to access disks.

    Some possible indicators include:

  • vprocs are reported as fatal** from vprocmanager status.
  • A database restart or restart loop.
  • Any errors following a system operating system restart or during the starting of PDE.
  • Errors in the /etc/.osm, or /var/adm/streams/* log files that indicate disk failures.
  • Note: Verify Pdisks automatically checks all pdisks for all AMP vprocs in the clique of the node on which it is run. To check the entire system, Verify Pdisks should be run on one node from each clique.

    Scenarios Examples

    Example  

    This example shows all pdisks on the current node are verified.

    > verify_pdisks
     
    All pdisks on this node verified.

    Example  

    This example shows two errors detected by Verify Pdisks.

    > verify_pdisks

    *****ERROR DETECTED*****
        subpool 1, pdisk /dev/pdisk/dsk1:
        disk id was 1, should be 1.
        system id was 0xF14EA20847AA36E0, should be 0x46A513645281BA31

    *****1 error(s) found during pdisk verification*****

    Example  

    This example shows an excerpt of Verify Pdisks output from the same system as the previous example, but in verbose mode.

    > verify_pdisks -v

    1276 bytes successfully read from Vconfig GDO
    TVS system-id from file: 0x46A513645281BA31
    Succesfully loaded libtvsaalloclib.so.
    This is node 002-10.
    It is in clique 1.
    Checking subpool 1 pdisks...
         pdisk 0: /dev/pdisk/dsk1....
    *****ERROR DETECTED*****
         subpool 1, pdisk /dev/pdisk/dsk1:
         disk id was 1, should be 1.
         system id was 0xF14EA20847AA36E0, should be 0x46A513645281BA31.

    *****1 error(s) found during pdisk verification*****
    Please check the vconfig.txt file and/or the hardware.

    Scenarios Vconfig Text File

    The file vconfig.txt describes the physical components of a system and how they are utilized. It lists the mappings of virtual elements to physical elements (such as vprocs to physical disk devices). These settings are stored in the Vconfig GDO, and automatically distributed to all nodes of the system.

    The vconfig text files can be inspected if Verify Pdisks reports errors in the configuration, however, configuration changes should be made only by using the Parallel Upgrade Tool (PUT). Do not edit the vconfig text file unless instructed to do so by Teradata Support Center personnel.

    The vconfig.txt file is located in /etc/opt/Teradata/tdconfig.