September 9, 201114 yr I'm confused. I'm using MD5 checksum to compare two files - one a copy of the other, an 8GB DVD ISO file - one on my USB hard drive attached directly to my PC and the other on my unRAID server. The two checksums don't match. OK - one file must be corrupt, right? So I ran the same checksum multiple times against the file on the USB drive. It comes up different every time! - Dodgy USB drive or lead, right? Then I ran it multiple times against the file on the unRAID server connected over gigabit ethernet - it also comes up different every time! What the heck is going on? Is there something I don't know about checksum tools not being able to accurately check 8GB files? Is there a way I can easily checksum the file directly on my unRAID server? I also tried two different checksum tools (Microsoft FCIV and FastSum). Not one checksum is ever the same... Whaat?
September 9, 201114 yr grab a copy of beyond compare and do a binary compare. it will tell you if the files are truly identical or not.
September 9, 201114 yr Author I actually have a licensed copy of Beyond Compare. I'll give it a try, thanks.
September 9, 201114 yr Author Same deal. Files don't match. Running a Memtest 86 scan now and will see what it says tomorrow. It passed one complete scan so far, so it looks like I might be OK for the RAM in my PC. Who knows though - this is just bizarre. Also running a compare with another machine shows a mismatch between practically every file on the USB drive and the unRAID server, so I guess there was some issue copying them. WTF? I thought there was supposed to be parity checking on read, network and write operations. This has just made me lose faith in my whole setup, rightly or wrongly. I guess DVD ISO files are designed to be resistant to corrupt or unreadable bits, so at least they will probably still play OK...
September 10, 201114 yr unraid wont verify what your copying, it protects what you gave it. if you gave if goobered files.. it protects the goobered files. It is a always a good idea to transfer large quantity of files with a program that verifies the write. Beyond Compare or Teracopy for example..
September 10, 201114 yr Author I'm not blaming unRAID. So far It seems to be an issue with my Win 7 PC. Memory checks out OK. I'll try disabling NetPeeker and see if that has an effect. I'll also try using SyncBack Pro to copy the files with verification from different PCs.
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