Why do different drives treat file name lengths differently

[magicant]

I have Windows 7 SP1 64bit. I am trying to find the best solution for keeping a regular backup of large amounts of data. I don't want to automate it. I want to manually do it every month or 2.

I have tried just copying and pasting everything using perigee copy (it bypasses windows prompts) and that usually works well, and at the end will give a list of files it skipped for some reason. I have also tried Allway Sync Pro. This works ok when files are already copied, but not trying an initial copy of large amounts of data.

Regarding my questions, I tried both methods on a new external western digital 2tb drive (usb powered) that came formatted in NTFS. I also reformatted and tried again. It skips a bunch of files that have long names or are maybe embedded too far in subfolders. Once I correct this, it copies fine. But I have another older drive in an enclosure (AC powered) and this never rejects those files. It is also NTFS. Why would one drive accept the copy and another reject it? I've had this problem with different drives since using Windows 7. And why is there no problem with the long file name on my internal hard drive that has the original?

Thank you for the help.

 

[ignatzatsonic]

The only problems I've had regarding copying and file name length involve the ENTIRE path length, not just the file name length.

Does one of these drives have a slightly longer name that might affect the path length rather than the file length per se?

Like maybe "WD" in one case and "backup" in the other. Or any other nuance that affects path length.

 

[mjf]

"In the Windows API (with some exceptions discussed in the following paragraphs), the maximum length for a path is MAX_PATH, which is defined as 260 characters. A local path is structured in the following order: drive letter, colon, backslash, name components separated by backslashes, and a terminating null character. For example, the maximum path on drive D is "D:\some 256-character path string<NUL>" where "<NUL>" represents the invisible terminating null character for the current system codepage. (The characters < > are used here for visual clarity and cannot be part of a valid path string.)"
Naming Files, Paths, and Namespaces (Windows)

It looks like one exceeds the 256 character limit.

 

[magicant]

The original, internal drive for the source files shows up in My Computer as:
(I) SG2TB
The path of the original files that I copy is:
I:\G (DOCUMENTS)\My Documents2\(all the files)


The external drive that works (which is a 2TB Western Digital, AC powered drive) shows up in My Computer as
(W) BACKUP
The path on this backup drive where I copy the files to is:
W:\Backup-12-30-14\(all the files I copy)

The external drive that has currently given me problems (which is a 2TB Western Digital, USB powered drive) shows up in My Computer as:
(P) My Passport
The path on this backup drive where I copy the files to is:
P:\_ANTHONY BACKUP_\I DRIVE\(all the files I copy)


So perhaps the problem is that the trouble drive has 2 folders above the files (similar to the internal drive) but the name of these folders are a little longer than the original?

NOTE: I left off the ":" after the drive letters from my computer as the : and the ) were converting to a smiley face.

 

[ignatzatsonic]

W:\Backup-12-30-14 is 18 characters.

P:\_ANTHONY BACKUP_\I DRIVE is 27 characters. This is the drive that is causing problems.

If my counting is correct.

So, I'd expect path problems to show up on the P drive before they show up on the W drive.

A difference of 9 characters, so a file name of maybe 235 characters would copy in one case and wouldn't in the other.

Shorten up the file name length of a few of your longest files as a test. See if they copy OK to the P drive with the short name.

 

[RolandJS]

One feature I like about Teracopy is that it will give you a long report -- with the trouble-files listed. I guess that's "after-warned."
Thanks to the previous posters about maximum character-spaces -- a reminder for me to always remember to take heed.

 

[magicant]

I did shorten the name of a few of the files (didn't count how much, just made them a lot shorter) then manually copied them over, and they copied. But I will try changed the initial characters of the drive next time and then copy again and see if it works. Thank you.

 

[magicant]

Although, looking at the original, internal drive (which obviously doesn't have the problem since the long files are there), it is:
I:\G (DOCUMENTS)\My Documents2\
which is 30 characters, if I counted correctly. So that is more than both external drives. Any idea why it doesn't have a problem?

I will still shorten the total characters of the external drive and give that another try.

Thanks.