Can a file be corrupted by copying from NFS to CIFS?

Question

I have Linux RedHat 6.x, and I mounted a Windows 2008 R2 NFS share.

If I copy data from my Linux machine to Windows, that doesn't seem like any harm. But if I take that file that is in my exported NFS share (the share on Windows), and I copy it to another Windows machine that is not using NFS, can that file be corrupted just because they are different file systems?

Example:

I needed space on my Linux machine for a backup, I backup to the mounted drive, which is the NFS share on the Windows server, I will then take the copied over files which are now on my Windows machine and copy them to another Windows server, just regular CIFS and NTFS, right-click copy paste, From there I have backup software to put it on tape, I cannot at this time have the Linux machine to directly to the machine with the tape drive.

Of course, I need to be able to restore those files, but if moving them between file systems somehow corrupts them.

Answer 1

There is always a possibility of something going wrong with the files during or after transit, although in your case it might be more likely to be at the point things are written to tape.

If the extra effort warrants it, I would calculate the MD5 or SHA1/SHA256 sums for the files on your Linux box and do that again on the Windows box on which the tape drive is attached. I have used MD5 on Windows at some point, and I assume executables for the SHA is available as well. If you cannot find an executable for either, install Python on the windows machine and use:

python -c "import hashlib; print hashlib.md5(open('xyz').read()).hexdigest();"

(replacing xyz with the filename).

Best is of course to run the MD5 check after reading back the files from tape, but that takes extra time.