As long as no write operation is performed running the analysis
should be safe. In fact Micromat's
Checkmate relies on exactly that. But Apple has a well established habit of adding new features and functions to the file system. Therefore DiskWarrior, TechTool Pro, and Drive Genius are all OCD about running on any OS version they have not been tested on and certified safe. For the same reason even though running the analysis
should be safe those same changes could easily cause those utilities to report either false negatives or false positives.
Disk Utility is no great shakes at repairing damaged file and volume structures but it is pretty good at finding and reporting errors. Unless and until I have a certified copy of DW, TTP, or DG I stick to Disk Utility for finding file and volume errors and if an error is found, hope DU will be capable of making the necessary repairs. Does that work? All I can say is, "so far, so good."
