Coridon Henshaw wrote in a message to All:

 CH> I have a program that needs to gather the names and
 CH> statistics of all files on any number of drives.  Would
 CH> there be any advantage in making the scanning subsystem 
 CH> multithreaded?

Yes, especially if the disks were on different controllers.

 CH> It seems to me that scanning two or more partitions at a
 CH> time would be faster than scanning only one at a time if the
 CH> partitions where on different physical disks and one or more
 CH> of the drives where SCSI.  Is this correct, or would there
 CH> be no advantage at all?

SCSI is not the problem, since it can intelligently reorder your requests. 
As you suspect, trying to multithread scans of two partitions on the same
physical disk would significantly increase head motion and greatly slow you
down, which is not what you want to happen.

 CH> In any case, how can I find out which physical disk a
 CH> partition is located on and the disk subsystem type?

You can call the Generic IOCtl facilities using Category 08h (IOCTL_DISK)
and 09h (IOCTL_PHYSICALDISK) commands, especially DSK_GETLOGICALMAP (21h). 
Be aware that a "physical disk" may not correspond to what you
think of as such if there are device drivers manipulating the tables to
create a RAID or striping volume, for example.
 
-- Mike


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