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Support Policy for Windows mount points and ClearCase

Technote (FAQ)


What is the support policy for IBM® Rational® ClearCase® VOBs and views stored on Microsoft® Windows® shares that are created from mount points (also known as junction points)?


A new feature in Windows® 2000 and later allows the creation of mount points on the workstation to other local partitions or local drives.

Mount points are persistent directories that point to disk volumes; in Windows, they always resolve to the root directory of the desired volume. Because mount points don't require that you associate each disk volume with a drive letter, they overcome Windows' drive-letter limitation (only 26 drives—A through Z) for disk drives.

If a shared directory is created in a mount point and used for ClearCase view storage, several problems result when attempting to work in a VOB. This technote provides a list of the known problems.

Rational has not qualified the compatibility of ClearCase with the use of mount points on Windows as a share for View or VOB storage; thus it is not supported.

The following is a list of errors that occurs if shares for ClearCase storage are used which are created from mount points on Windows.

  • Attempting to check in a file that was previously checked out from within a view created under a mount point returns with:

    Error checking in "O:\vobname\folder\checkedoutfile"
    Unable to access "O:\vobname\folder\checkedoutfile" file does not exist.

  • Creation of a new folder in a mount point returns with a Windows error:

    You may be unable to access files created in "O:\vobname\newfolder" would you like to continue?

    Note: Clicking Yes or No results in directory creation. If the directory is added to source control ClearCase creates a second folder with a .mkelem extension which appears as a view-private directory.

  • Attempting to create a new file under the newly created folder returns another Windows error:

    "Unable to create the file 'New Text Document'
    The system cannot find the file specified"

    Note: Refreshing Windows Explorer causes the file New Text Document.txt to appear.

  • Attempting to add this file to source control results in the following errors:

    Error adding the file 'O:\vobname\newfolder\New Text Document.txt' to source control
    "Created element "New Text Document.txt"
    INTERNAL ERROR detected and logged with the NT Event Service/
    See the Event Viewer for the error message.
    Internal Error detected in ".\../map_cache.c" line 1722
    Invalid input arguments to "map_obj_oid_to_dbid".
    Unable to checkout "O"\vobname\newfolder\New Text Document.txt

    Note: The Windows Event Viewer shows no errors at this time. It appears that adding the file to source has failed, however if you attempt to add it a second time, the following error occurs:

    Error adding the file 'O:\vobname\newfolder\New Text Document.txt' to source control
    Unable to create element "O:\vobname\newfolder\New Text Document.txt"
    The element "New Text Document.txt already exists.

    Note: Opening a command prompt and issuing a cleartool ls from the bad view shows the following output:

    O:\vobname\newfolder>cleartool ls
    New Text Document.txt
    New Text Document.txt@@ [eclipsed]

  • When working in a known good view (created in a normal network share), change into the directory created in the bad view "new folder" and create a new file (for example alpha.txt). You can add this file to source control successfully.

    Note: Switching back to the bad view and trying to checkout alpha.txt returns with:

    Error checking out 'O:\vobname\newfolder\alpha.txt'
    Checked out version but could not copy data 'O:\vobname\newfolder\alpha.txt' to view: No such file or directory
    Correct the condition, then uncheckout and re-checkout the element.
    Unable to check out 'O:\vobname\newfolder\alpha.txt'

    Note: After all these errors alpha.txt is in fact checkedout and cannot be checked in again returning with:

    Error checking in 'O:\vobname\newfolder\alpha.txt'
    unable to access 'O:\vobname\newfolder\alpha.txt'" No such file or directory.

Related information

About NTFS Junction Points

Cross reference information
Segment Product Component Platform Version Edition
Software Development Rational ClearCase Operating System Configurations

Document information

More support for: Rational ClearCase
Operating System Configurations

Software version: 2002.05.00, 2003.06.00, 2003.06.01, 2003.06.10, 2003.06.12, 2003.06.13, 2003.06.14, 2003.06.15

Operating system(s): Windows

Reference #: 1149102

Modified date: 16 July 2008

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