This is a follow-up to my post about Data Management and is a more detailed look at the procedure for DMTs to follow on set.
The same production company asked me to write this up for them, since on their smaller productions, they sometimes end up having someone inexperienced dumping cards. They asked for a step-by-step guide, so that they could grab any person off the street and be confident that the cards would be copied correctly. And while I don’t recommend doing that (and they would never actually do that), I think that they would be able to do that with this guide.
- ALWAYS BACKUP DATA TO AT LEAST TWO HARD DRIVES.
- ALWAYS BACKUP DATA TO HARD DRIVES DIRECTLY FROM THE CAMERA MEDIA. Never copy data from one drive to another.
- NEVER USE A COMPUTER’S INTERNAL HARD DRIVE AS A BACKUP DRIVE.
- This guide assumes you are using a Mac with OSX. The procedure will be slightly different on Windows, but will be generally the same.
1. Shutdown any non-essential programs and disconnect any non-essential devices. When a computer is backing up media, that should be the only function it is performing.
2. Connect the two drives to the computer. Thunderbolt or USB 3 are the fastest connections and should be the preferred choices. If the drives do not support either of those, use USB 2. Always make sure that the drives are connected in such a way that they do not have to be disconnected and reconnected at all during the production day.
3. Connect the media reader. Use the same preference for connections as for the drives.
4. If either of the hard drives are brand new, it will need to be formatted. If both have previous data on them, do not format them and skip to step 5.
4a. Open Disk Utility. From the window on the left, select the drive you wish to format. From the window on the right, select “Erase.” Set the format to “Mac OS Extended (Journaled)” and name the drive, making sure to include the capacity of the drive at the end of the name. If you have two new drives, they should be given paired names (i.e. “Lewis 2TB” and “Clark 2TB”). Click erase.
4b. Using a label maker or white gaff tape and a sharpie, label the physical drive with the same name you gave it in Disk Utility.
5. Open DaVinci Resolve. Login and create a new project. The name should be the reverse date and the name of the shoot (i.e. yyyy-mm-dd Project X).
6. From the Library window, navigate to one of the drives. Create a top level folder in it with the same name as you gave the Resolve project. Within that folder, create a “Raw Footage” folder and an “Audio” folder. If the shoot will take place over multiple days, make a subfolder in both “Raw Footage” and “Audio” with today’s date in reverse order. If there are multiple cameras on the shoot, create a subfolder for each within the “Raw Footage” subfolder for today (if the shoot is only one day, the camera subfolders can go directly in “Raw Footage.”) Copy all the folders created in this step onto the second drive.
7. Select “Clone Tool.” This is the icon just above the Media Pool window.
8. Once you get a card from the camera, remove the mag tag and place it on top of the reader. Insert the media into the reader. On both drives, create a new subfolder within the folder for the camera it came from. Give this new subfolder the same name as is on the media’s mag tag.
9. From the Library window, find the camera media and right click on it. Select “Set as Clone Source.”
10. Still in the Library window, find one of the folder you created in step 8 and right click on it. Select “Set as Clone Destination.” Repeat with the other folder from step 8.
11. In the Clone Tool window, you should now see three file paths. The top one will have a downward facing arrow to the left of it and the file path should be for the camera media. The bottom two should have a file box to the left of them and the file paths should be for the folders you created in step 8. Once you have confirmed that this is the case, click “Clone.” This will begin the backup.
12. Once the backup is complete, open Finder and navigate to one of the folders from step 8. Inside should now be the contents of the camera media, plus a text file called md5sums. Open this. You should see strings of nonsense numbers and letters followed by filenames. Note the first filename. Leaving this text file open, return to Finder and navigate to the camera media. Find the file with the same name as the filename you noted from md5sums.
13. Open Terminal. Type “md5” followed by a space. From finder, drag the file on the camera media to the terminal window and press enter. This will generate a hash. Compare this hash to the matching file’s hash in md5sums. They should be the same.
14. Repeat steps 12 and 13 with a few other randomly selected files and confirm that the hashes match. If it is reasonable to check all the backed up files, do that.
15. Once you have verified the backups, you can eject the camera media and return it to one of the ACs.
16. Repeat steps 8 through 15 with each new card.
17. After you have verified the last card of the day, close Resolve. You do not need to save the project. Eject the drives and shut off the computer.
Production only gave you one backup drive
Immediately inform production. Ask if they are comfortable having only one copy of the footage and remind them that if anything happens to the drive, they will lose the entire day’s work. Most producers will understand the importance of having redundant backups and be happy to get a second drive. If not, it’s their choice and if something goes wrong, your ass is covered.
The computer doesn’t have enough ports for me to connect both hard drives and a media reader
If your computer and drives both have Thunderbolt, remember that it can daisy-chain devices together. You may need additional cables to make this work. If daisy-chaining will not solve the problem, you will need a USB 3 hub. In either case, if you need production to buy something, immediately inform them of the problem and let them know that the solution is as simple as buying a cable or USB 3 hub and will cost them under $50. Most producers will understand the importance of not disconnecting and reconnecting drives multiple times and be happy to get you what you need. If not, it’s their choice and if something goes wrong because they didn’t get you what you need, your ass is covered.
The media doesn’t have a mag tag on it
If there is no mag tag on the media, you need to immediately talk to one of the ACs. Untagged media may indicate that they did not give you the correct media or they are not tagging media. If they gave you the wrong media, get the correct one. If they are not tagging media, insist that they start doing so. Media with a mag tag taped over the contacts lets everyone know that there is un-copied footage on it. When you take the mag tag off the media and put it on the reader, it is a reminder to you of either what media is in the reader or what the last mag backed up was. When you give a mag without a tag back to the ACs, they know that means it has been backed up and is safe to format.
Resolve encounters an error in backing up the camera media to the drives
Figure out how much data was successfully backed up, then delete the partial media backup and retry. If it fails again, try to backup manually by dragging and dropping with Finder. You can use Terminal to generate and verify checksums. If this fails, something in the chain is corrupted. Immediately inform an AC.
The md5 hashes don’t match between the camera media file and the drive file
First, double check that you were matching the same file. If you were, then manually transfer the file from the camera media to the drive using Finder. Use Terminal to generate md5 hashes for the original and manually transferred file. If the hashes still do not match, open the camera media file in an app you can play it in (eg Redcine-X or Quicktime) and watch it the whole way through, looking for errors. If there is an error, it likely means the media is corrupt. Immediately inform an AC of the problem. If there is not an error, then open the file transferred with Resolve in a player and watch it through. If the Resolve transferred file plays fine and matches the camera media file, then you should be okay. If there is a discrepancy, watch the manually transferred file. If there is no issue here, overwrite the Resolve transferred file with the manually transferred file. If there is still an issue, immediately inform an AC.
One or both of the drives run out of free space
This is the one situation where backing up to the computer’s internal hard drive is acceptable. Begin the backup, then immediately inform production of the problem. Most producers will understand and purchase extra drives. Do not delete files from the drive to clear space, even if asked; it’s not your job to decide what is worth keeping and what isn’t. Once you receive new drives, transfer the backup on the computer’s internal hard drive to the new drives as if the computer’s drive was camera media.