[xubuntu-users] Peculiarities with copying large files to a flash drive, Xubuntu 12.04

[Pasi Lallinaho]

Forwarding this mail to xubuntu-users, which is appropriate.

Pasi

On 06/11/2012 10:00 PM, Len E. wrote:
> (The situation described herein may be of interest
>   to the development team).
>
> A large .iso file (Debian 6.0.5 DVD), 4.4GB size, which
> had been downloaded from the Debian website was copied
> to an 8GB flash drive formatted as NTFS.  The checksum,
> using MD5calc from the terminal command line, matched 
> with the posted value on the website, both for the 
> downloaded file, and the file copy on the flash drive.
>
> When the flash drive was mounted on a Vista PC (which
> has the DVD burner), the checksum value calculated there,
> both on the flash drive and on the file copied to the
> Vista hard disk did not match the posted value.
>
> What was most unusual, was that when the flash drive
> was remounted onto the Xubuntu machine, the checksum
> value no longer matched the posted value, even though
> no further write operations to the flash drive had
> occurred.
>
> This process was repeated a few times, alternately
> using the cp terminal command, and a copy/paste operation
> to transfer the .iso file to the flash drive.
> (Between attempts, the flash drive was reformatted to NTFS
> using Gparted on Xubuntu).   The peculiar results were
> the same with each attempt.
>
> The final attempt was to put the .iso file into a tar 
> archive on Xubuntu, then cp the archive onto the flash
> drive.  On Vista, the 7zip utility was used to extract the
> .iso from the tar archive.
>
> The checksum for the extracted .iso file DID MATCH THE
> POSTED ORIGINAL VALUE !!
>
> I don't really understand what is happening, but I'm
> pleased to have a work-around using the tar archive if
> I have similar large-file transfer requirements in the
> future.
>
> For your consideration .....
>
>  
>
>


-- 
Pasi Lallinaho (knome)                      » http://open.knome.fi/
Leader of Shimmer Project and Xubuntu       » http://shimmerproject.org/
Graphic artist, webdesigner, Ubuntu member  » http://xubuntu.org/