The CONVERT LIBRARY command creates a copy of an existing CMS
    library and converts the copy for use with this version of
    CMS. Libraries created with CMS Version 3.0 do not need to be
    converted.

    To convert a library, you must first create an empty directory
    to contain the new, converted library. Conversion maintains
    everything in your existing library, including the reference
    copy directory. After the library is converted, CMS automatically
    executes the VERIFY/REPAIR command to ensure that any existing
    reference copy directory is valid and current.

    The CONVERT LIBRARY command causes an unusual occurrence to be
    logged in the history file.