The disk is filled with many files like null-resource-*.ser in the crx-quickstart/launchpad/installer folder. The files occupy GB of space.  Cleaning and restarting the system continuously creates another file with null-resource-*.ser.

Solution

1. Remove the null-resource-*.ser file.
2. Install the additional bundles that contain a fix to avoid creating new null-resource-*.ser files.
   1. Unzip installer_update.zip which contains a bundle [1].
      
   2. Using Apache Felix Webconsole, install three bundles listed at [1].

[1]

org.apache.sling.installer.core: 3.2.3-R1221231
org.apache.sling.installer.factory.configuration: 1.0.3-R1186760
org.apache.sling.installer.provider.jcr: 3.1.1-R1213753