Re: How to check integrity of files after big copy
Can you run any commands on the NAS box (i.e. does it have a Linux terminal you can access over SSH?)
If so, use the md5sum command on the files on your hard disk and record the results:
Now SSH into the NAS box and run basically the same command to generate the MD5 sums for the original copies of the videos. Compare the "sums.txt" file on the NAS box with the one on your computer. If the video files differ in any way, their sums will be totally different. (you can compare the sums.txt files side-by-side by eye in Gedit, or use the 'diff' command to quickly show you any differences).
md5sum /media/Harddisk/Videos/* > sums.txt
If you don't have SSH access to the NAS, if you tried the md5sum trick you'd basically be copying the video files to your computer again! You might as well just copy them all again to your hard disk, if you're in doubt.
I'd say that if you didn't get any error messages during the copy, that everything would be okay. Linux is very fussy about getting things right, and any errors during read or write will cause an Input/Output error message.
I try to treat the cause, not the symptom. I avoid the terminal in instructions, unless it's easier or necessary. My instructions will work within the Ubuntu system, instead of breaking or subverting it. Those are the three guarantees to the helpee.