I know this thread is several months old and is without a satisfactory conclusion, but it seems worth reporting on something I discovered today using ROBOCOPY, and then looked up on these forums to see if it had previously been encountered - and it had, by Jim Kelly.
Yesterday I had copied the contents of a Maxstor OneTouch II external drive, NTFS formatted, to my new LinkStation Pro LS-XHL (firmware is the UK v1.20), using ROBOCOPY (XP-010) with the /MIR (mirror) option. This took about 12 hours.
Since the Maxtor gets updated daily with backup files from my PC's hard disk, I decided to copy any new files written on the Maxstor drive since yesterday to the LinkStation Pro,and found that far too many files were being copied across which ROBOCOPY thought were newer than those copied yesterday to the Linkstation Pro. So I abandoned this run.
I then did two ROBOCOPY tests using the /L option (which does all the file timestamp comparisons, but doesn't do the actual copying, so that the Maxtor and the Linkstation are both left in the same state after as they were before). I got the following results:
Total Copied Skipped
Files : 573566 184068 389498
Bytes : 244.405 GB 161.705 GB 82.700 GB
This action had clearly 'copied' a huge number of files which were classed as Newer on the Maxtor, but which I was certain had not altered siince the previous copy.
So I used the ROBOCOPY /FFT option (whose meaning is to ignore file timestamp differences of up to 2 seconds) and the results were now:
Total Copied Skipped
Files : 573566 14382 559184
Bytes : 244.405 GB 31.816 GB 212.589 GB
Inspecting the ROBOCOPY log showed that in the total of files that would have been copied across to the LinkStation Pro there were still a number of so-called 'newer' files which hadn't in fact been changed, but nowhere near as many as when the exact file timestamp comparison was made (previous test).
So I would allege that the file timestamp data that Windows is given by the Linkstation Pro (in this case) can be inaccurately low by as many as two seconds, and occasionally more.
Surely the LinkStation Pro's NTFS file system 'appearance' to Windows should be identical to that of a 'real' NTFS file system, and that includes file timestamp data?
I don't have the enthusiasm to examine these file timestamps to the 100 ns granularity offered by 'real' NTFS, nor whether consistent timestamp data is returned for the same file on different occasions, but probably some of the Buffalo techies should, to determine how this inaccuracy can be resolved.
Thanks!