C-fast card problem

I have Ursa mini 4.6k PL latest firmware and I used scandisk 256gb cards for 4k 16x9 recording in prores 422hq.
Today I was shooting and as first card fill up, camera started to record to 2nd card. When I stopped I want to offload cards, I offloaded 1st and then started to offload 2nd. When I inserted it to macbook 10.12.5 pro via lexar usb reader is showed like I inserted 1st card, but I did inserted 2nd card. as content it shows 1st card content, but mov files are unreadable. is it possible that some how card structure got hit and now it is broken?

Any ideas how to fix it?

Regards

Kristjan-Jaak
jaak.me

Hi,

I think I know exactly what happened here. Had the same three days ago when a colleague offloaded the data because I was busy preparing the next shot and he came back saying the second card is corrupted and his mac asked him to "initialize the media".

Here is why this happens: Some card readers, HD docks and so on have a "flaw". If you have the reader with a card connected to your macbook and you remove the card from the reader, then the mac will NOT detect, that the media has been disconnected. It still thinks, that your card (lets assume this is media A001) is still connected. Your mac will only detect the missing media if you disconnect the whole card reader!
Lets get back to the previous situation: You have removed your A001 card. Your mac still thinks it has A001 inserted, because you have not disconnected the whole card reader. Now you are going to insert the next card A002.
As soon as you access the card the file system will be trashed completely, because the mac still thinks it is reading and writing to A001. But it actually is reading and writing from the new A002 card. This screws the file system up. You can compare it to a book. Lets say you have book one and you know from its index, that the info you want is on page 100. Now someone exchanges your book without you noticing it. Now you are trying to get the needed information from page 100. But the new book obviously has some different information on page 100. A computer cannot deal with this and screws it up, making the card unreadable.

Do NOT try to repair the card with disk utility. Disk utility will use a backup boot sector data to restore the file system. But this backup index is the index from the previous media! If disk utility overwrites the damaged structure with the backup index, then you will be able to read the drive, but all video files are destroyed, because the index refers to start and end points of the clips of the PREVIEOUS media, which is A001. At this point you are most likely not able to completely restore all your footage.

So, if you happen to get the card corrupted and the mac asks you to initalize the media, do nothing!! Download Data Rescue 4. This tool was the only tool which was able to reliably recover all the files!

You can prevent it the next time, if you disconnect and reconnect the card reader when you change cards.

If you need any help, message me.

Best regards,

Florian Duning

Thank You Florian!

You have good point there!

When I inserted the card it did not asked me to initialise, it showed the 1st card

I did tried to fix it with disk utility and nothing happened, then I for no reason hit restore in Disk Utilty and it showed me some kind of problem, next ting was "INITILAIZE" ....uhh

Then I took from Transcend site RecoverRX and it found all the files overnight and data was recovered, before hand RecoverRX couldn't find anything....feels like card must be unreadable if You want to fix it

all good, that end's good.
Good lesson to learn from here and go on!

All the best!

Jaak

htp://jaak.me

Just an anecdote how old this kind of problem is:
In 1995 I was working at my dad's graphic design office and we had a big project from last year saved on two-sided MO disk (magneto optical disk) and on DAT tape. MO disks could store the huge (at that time) size of 512 MB per side and was read by an external device connected via SCSI.
To throw out the disk you had to un-mount it by dragging the symbol to the trashcan, then press the physical eject button on the device. Quite save to use.
But if you switched the device later on (after the PowerMac was already up and running) you had to use a tool to mount the device. But then the eject button wasn't locked before un-mounting anymore.

One day I was working with data from side A of a disk and had a finder window open with the content. Then I pushed the eject button without un-mounting the disk, flipped it to side B and put it back in. And then I closed the finder window. Bang. All data lost because the MacOS finder corrupted the file system.
Couldn't restore it with the tools available.

Plan B was to restore from tape - but unfortunately exactly this tape was unreadable. 2 month's work was lost and I had to re-create it from scratch...

Murphy's law in full glory.

Remember on macOS, after you have finished offloading media from your card, you must Eject the card and then you can safely remove the card from the reader.

If you forget to do thus, macOS will warn you. 99 times out of 100, you may be fine, but who wants to risk it?


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