HP-UX automounter issues with large database files and remote VOB storage

Technote (troubleshooting)


Problem(Abstract)

This technote explains some additional issues (specifically Value to large for defined datatype errors and misreporting of file sizes for files greater than 2GB) that may occur when moving IBM® Rational® ClearCase® VOBs hosted by HP-UX® servers from local to remote storage.

Cause

These issues can occur on HP-UX 11.x hosts when the legacy "automount" command is used instead of the newer "AutoFS". The older "automount" command is limited to using NFS version 2 (NFSv2) to mount remote storage. NFSv2 is limited to accessing files that are 2GB or smaller.

Symptom #1:


    The misreporting of the file size occurs when using certain NAS devices that will "translate" the file size to 2GB. While this allows the database files to be OPENED across the NFSv2 mount, attempts to modify the data may result in data being written in undesired locations and could lead to data corruption.

Symptom #2:

    When a file exceeds the maximum size for NFS version 2, the file may not normally be opened across an NFSv2 mount. During the process of opening the file, attempts will be made by the operating system to retrieve the size of the file. If the size of the file exceeds the maximum size for NFSv2, the operating system will report an illegal file size to the opening process, which will then fail with the "Value too large for defined datatype" error.

Resolving the problem

Enable the AutoFS automounter.

  1. Edit /etc/rc.config.d/nfsconf and set the following variables if not already applied:
    • AUTOMOUNT=1
      AUTO_MASTER=”/etc/auto_master”
      AUTOMOUNT_OPTIONS=”-f $AUTO_MASTER”
      AUTOMOUNTD_OPTIONS=
      AUTOFS=1
  2. Edit /etc/auto_master to force hard mounts, NFS v3, and a few other options for the appropriate automount map:
    • vers=3,proto=udp, rsize=32768, wsize=32768,hard
  3. Reboot the server.

Note: The options in step #2 should be the default setting for HP-UX 11i. This step merely hard-codes the options in the auto_master file.



Related information

ClearCase database file size 2 GB limitation

Cross Reference information
Segment Product Component Platform Version Edition
Software Development Rational ClearCase Mount HP-UX
Software Development Rational ClearCase Database HP-UX
Software Development Rational ClearCase Interop: NAS HP-UX

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Document information


More support for:

Rational ClearCase
Operating System Configurations

Software version:

2002.05.00, 2003.06.00

Operating system(s):

HP-UX

Reference #:

1227557

Modified date:

2006-01-10

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