How does the probe handle symbolic links?
The probe ignores symbolic links. Thus, if it is scanning a directory tree and encounters a symbolic link to another area of the file system, it will not follow it.
How does the probe handle hard links?
The probe attempts to detect if two files in the tree it is scanning point to the same data and automatically ignores the duplication.
How does the probe handle sparse files?
By default, the probe is not aware of sparse files. This means that it will read zero values for the sparse regions of the files, which can result in artificially high data reduction. The probe reports zero chunks, which hints at this potential issue. Refer to Understanding VAST Probe Output for more details. Note that the probe can be run to recognize sparse files on some file systems, as described in the referenced document.
Can the probe scan multiple unrelated directory trees?
Yes, it can. This is done by providing multiple --input-dir values.