DiskSurveyor FAQ

Question:
Is DiskSurveyor "Year 2000 (Y2K) Compliant?"

Answer:
Yes. The only date/time calls it makes are getting the files' and folders' Modified Date info. However, in the older DiskSurveyor 1.x versions, when you saved a DiskSummary file, you can see in each item in the list that the date was abbreviated YYMMDD. (April 7 1999 was represented as 990407, January 1 2000 as 000101). DiskSurveyor 2.0 now saves the dates as YYYYMMDD and can read any DiskSummary files written by any of the older versions. If you load an old DiskSummary file back in, DiskSurveyor assumes any year >= 84 (the year the Mac was introduced) is in the 20th centry and any value < 84 is in the 21st. So, in 2084, it might start getting confused... that is, if anyone still has any files older than 100 years on their disk. :-)

Question:
How come there are no scroll bars in DiskSurveyor? I don't see all my files.

Answer:
If you're still using DiskSurveyor 1.x, the window that you see should represent 100% of the allocated space on the disk or folder you are scanning. (If a folder contains files and folders that take up half the disk, it is displayed as half of the window.) DiskSurveyor 2.0 now lets you resize and move the scanning window around the desktop. (Position and size will be remembered next time DiskSurveyor is launched.)

Sometimes not every folder or files produces a bar thick enough to write its name on. And if the files are really small (compared to the disk or folder you are scanning), they show up as a single line. If you place the cursor on the bar representing the folder or file, it should display the file or folder name in the status bar at the top. (It will also show the percentage of the disk used by that file or folder if it's at least 1 percent of the disk.)

Remember, DiskSurveyor was created to identify the large file and folders, and not necessarily to show every small file.

Question:
How come DiskSurveyor is only displaying part of my disk?

Answer:
One possible cause could be if you are using any of the automatic (driver-level) compression programs like DiskDoubler, SpaceSaver or Stacker, etc... Apparently, they 'lie' to the Operating System about how big a file is (they tell it the original size, not the compressed size), and in this case you can appear to have more space used by files than the disk thinks it has... which causes DiskSurveyor to not display the 'extra' space.

Question:
...and how about this CDROM?

Answer:
I have come across some CDROMs (mostly multi-platform) that have an incorrect value for the volume's total allocated bytes.

When DiskSurveyor scans a volume, it gets the total allocated blocks that the volume thinks it has... that way it can display the files and folders as it finds them (as the correct percentage of the disk). (That's also why it can't display them as it scans a folder... it doesn't know the total number of bytes used by all the files in the folder until it scans through them... kind of a Catch-22... There's no Toolbox call to tell you how many bytes are allocated in a folder.)

This problem was corrected in DiskSurveyor 1.3.
At the end of scanning the volume, DiskSurveyor compares the total number of bytes read with the value that the volume reported, and if they disagree, it adjusts the page so the higher number is 100% of the window, and brings up a warning dialog that the totals disagree. (There is a preference to disable this warning, since those using driver-level compression programs would be constantly warned.)