MDADM/Samba/Ext4 video corruption issue
Im running Ubuntu 12.04.1 LTS as the OS on my main media file server at home. It has a 6 x 2TB Raid 5 array (mdadm) that I use to house backups of my music and movies, which in turn I am able to stream to various playback devices around the house (samba).
This has been working like a dream ever since it was set up. However, I recently noticed a problem with video corruption in some of the more recent rips I've made. My first investigation was with the application forums:
If I perform the whole ripping process locally, no errors occur. The "glitches" are introduced even by a simple samba file copy from a Win 7 box to the Ubuntu file server.
I can reproduce this, with one file in particular returning a different MD5 hash every time I copy it over to the Ubuntu box (though total byte count is always correct). Local copies result in a file with an identical MD5 hash 100% of the time. I also attempted copying the file using SCP instead of samba and the resulting file still produced a bad MD5 hash.
Therefore, I assume there must be an issue with either the underlying RAID array (mdadm), file system (ext4) or sharing mechanism (samba/scp).
Can anybody advise some troubleshooting steps that might help me track down the culprit?
Thanks in advance