Problem copying a .DMG file to a USB hard disk
 

Hello,

I recently came up with a tricky problem.
I have a set of DMG files stored on a Windows XP server (the DMG files are originally coming from a Mac OS X 10.4 system).

When I try to transfer the files to an external usb Hard disk the process hangs in the middle and it looks like there is no possibility to transfer the files to the external hard disk. (no problem in transfering other types of files)

The funny thing is that I can transfer the same files without any problems to another internal SATA drive in the same system or to another PC through the network.

I thought about broblems with the USB drives, I tried several different brands, formatted them several time, check for bad sectors and file integrity both on the origin hard disk and the destination USB disk without finding anything abnormal.

Do you have any idea, or way to solve the problem?

Cheers
LV

Re: Problem copying a .DMG file to a USB hard disk
 

I can think of a few possibilities, but they are not all-inclusive:

- The files may be in a form where they must occupy contiguous disk memory. Defragmenting the USB drive may fix this.

- The file may contain a code combination which is an escape sequence for USB.

- The format (as opposed to the file) of the hard disk may have tangled links. Do a chkdsk (or equivalent) on the source disk.

Re: Problem copying a .DMG file to a USB hard disk
 

few additional explanations:
- I'm trying to copy to a freshly formatted USB disk. (formatted with the computer management tool of Windows XP)
- I have launched several times a CHKDSK e: /f /r (e: is the volume containing the files)

You are mentioning escape sequences for USB. This might be a possibility since the files are coming straight from an Mac OS X hard disk. I tried to find more info about USB escape sequences without success. Could you tell me more about this?

Cheers
LV

Re: Problem copying a .DMG file to a USB hard disk
 

I don't kjnow your drive.

There are certain byte combinations for any communications link which are gobbled by the link itself. So any binary file protocol must be designed to avoid such combinations.

Re: Problem copying a .DMG file to a USB hard disk
 

Right! I guess that the Windows USB driver and the USB interface hardware should prevent this from happening. As far as I remember the USB protocol encapsulate the data into frames... so I assume (not sure on that) that the content/type of file is not playing any part in this.

The PC is running windows XP. The motherboard is an "Asus A8N-Sli deluxe" and has an AMD Athlon64 with an nVidia nForce4 chipset. (I'm not sure about the USB bridge chip). Fort the hard disk I've tryed 3 different USB drives from different makes so I believe it's not playing a part in this.

I'll try to update all the drivers and see what happens... :eek: