DCP-o-matic

Looking for some advice on copying my DCP folders onto target drives without flipped bits. Sometimes it takes 6+ attempts to copy all the files to a drive and pass hash checks with dcp_inspect! The system is a higher end PC running the newest version of Ubuntu and the target drives are EXT2 formatted externals connected via USB3.

I've tried using the regular cp command, rsync, UI drag-and-drop.... Tried copying over the network vs from a local source drive... Even tried plugging the drive into a USB2 port thinking the slower speed would increase the copying accuracy -- Nope!

Is there a file copying solution that does hash checks or other verification as it goes along, so I don't have to waste so much time copying and checking 150GB packages over and over??

Thanks in advance!

There's nothing special or "magical" about copying the DCP files. Normal copy procedures should work, no matter if you use the command line or some graphical interface.

I think it's likely that there's some hardware fault in your computer. Memory error, some problem with the disc controller or even with the internal hard disc itself. The power supply - if faulty - can also cause all kinds of strange errors.

You can start by running Memtest86+. Let it run for several hours and see if it catches any memory errors.
http://www.memtest.org/

If not, the problem is probably with the disc controller or hard disc. Several different strategies might apply for troubleshooting depending on your hardware. Replacing cards, switching things around internally, using external hard discs instead of internal etc.

I did have some issues with USB3 drives. I built a CRU drive slot into my rendering machine a while ago, and I create my DCPs directly onto that drive. That way, DCP-o-matic hashes the files actually on the distribution drive, and there is no additional copy involved.

You could also use the CRU movedock, with the eSATA option, preferable.


- Carsten

USB3 or not, I'm still of the opinion that if you can't reliably copy a file from one disc to another without some bits getting corrupted, then you've got some sort of hardware problem. Or possibly, but not very likely, a serious bug in the operating system.

That's certainly true. Even 200+Gbytes of data should copy 100% bit-identical in everyday scenarios.


- Carsten

Hi,

I am having the same copy issue. I checked my RAM with REMBER and my ram looks OK.

I am on Hackintosh. Can that be a issue ? May be with some drivers or something ??

I read in one of the post that insuffcient power supply can cause this problem too . Is it true ??

Thanks in advance
Kmeh7

Hi,

I exported a dcp to my internal harddisk and that dcp showed error in HASH check.

I am on Hack and i checked my internal harddisk with " repair disk" in disk utility and the disk is fine.


As told by carsten i checked my Ram and it looks fine. (Checked with Rember )

Any help would be great and thanks in advance ™

Kmeh7

Now, the interesting question is, is are your files corrupt, or is your hash checking buggy?

Tell us about your full system configuration, disk format, OS, etc.

- Carsten

Hi ,

Hash Check is perfect cos DCP did not get verify at server.

It's a long shot, but you may try to boot a different/minimal OS and try to copy from there. Although it is hard to believe there could be a substantial flaw in file copy integrity which doesn't show in everyday operations (e.g. swap file).

Admittedly, I have no idea what to advise here, other than changing components/drivers one by one...

I have never come across that sort of problem, except for an unreliable USB3 addon card. Also, I never touch the system when copying large files.

- Carsten