Migrating data in increments

For large migrations, you can plan ahead to migrate the data in small increments. Use the --prevDirs and --prevDirsFile options of the export command.

About this task

When you export a large amount of data, you can identify subdirectories under the export root and then export and import them separately. At the end, you export and import the root, and then you can specify the --prevDirs option to exclude previously exported files from your current export. The syntax of the --prevDirs and --prevDirsFile options is:
> ccc export ccase -d <intermediate data directory>
	-i <View-relative root path to export>
	--prevDirs <space-separated previously exported data path>
	--prevDirsFile <path to a text file that contains previously exported data path>


  1. Export the subdirectories. For example, if the directory is M:\aView\aVOB\aRoot, you can identify the subdirectories to export to:
    > ccc export ccase -d C:\data\sub1 -i M:\aView\aVOB\aRoot\sub1
    > ccc export ccase -d C:\data\sub2 -i M:\aView\aVOB\aRoot\sub2
    > ccc export ccase -d C:\data\sub3 -i M:\aView\aVOB\aRoot\sub3
  2. Then, export the root using the --prevDirs option:
    > ccc export ccase -d C:\data\aRoot -i M:\aView\aVOB\aRoot 
    	--prevDirs C:\data\sub1 C:\data\sub2 C:\data\sub3


The export and import of the root is divided to four operations, and all commands finish in a reasonable amount of time. You can also use the --prevDirs or --prevDirsFile options when you have additional check-in versions to migrate at the same root, or when you have additional Rational® ClearCase® views to migrate.

What to do next

When you run the import commands, they run in the same order as you exported them.