Vault broken and sanitizer seems unable to fix


for a while now I am testing the combination of MountainDuck and Cryptomator (integrated into MountainDuck) as an option to do encrypted online backups to OneDrive.
The backup folder contains many photos and videos in a directory tree, about 400GB total.

The main reason to use MountainDuck is to avoid having to have a local copy of the backup.

After some time now, the vault seems to have become corrupt. The problem seems to be that in Cryptomators metadata, some directories which I copied exist, but the physical encrypted directories seem not to. The clearest error message is given by CyberDuck, which explicitly tell the directory does not exist.

Cryptomator itself only hangs when I try to open the directory and MountainDuck reports it as empty. If I try to copy the content into it, this hangs and fails.

I have found the sanitizer on Github, but that tool seems to be in too early stages. After a while, it tells me there are 60k+ files in the vault, but for hour and hours to come, it does tell anything useful.

All in all, I am a bit frustrated and am not sure if my use-case really can be covered by above combination.

Is there any advice from you more experienced folks?


So nobody here has experience or advice for repairing a remote-only vault?
Is this such an uncommon scenario?

Well this is not the cyberduck or mountainduck support, so I’m not sure if there are as many experienced users here as you think.
If you are having problems with this tools, I recommend to contact their support:

Cryptomator is open source. Means they can chance the code. If there is an issue with Cryptomator, I’m sure they will tell the team.

And if you want to have sanitizer support, I think it would be good to give more information what’s going on. As far as I know, if a vault is corrupt, sanitizer throws out tons of messages.

I also use cyberduck without any problems so far, so I cannot give you an advice what your problem might be.
But as you report that there are folders and files disappearing then I would investigate why.
As you do not have a local sync, something else is deleting your files.

Thanks for your answer, Michael.

I know this forum is for Cryptomator and I came here because my main question is how to check / fix the remote-only Cryptomator vault as easy as possible.

Probably I could copy the multi-hundred MBs 1:1 to a local drive and try sanitizer there, but that does not sound like a reasonable approach (esp. if this might happen again in the future).

Even if a network flaw or similar might have happened when storing something to the vault, my expectation is that Cryptomator needs to have techniques to do metadata and data writes in an “atomic” way, otherwise corrupting a vault could happen pretty easily. With a remote only drive of course the chance of write errors is higher, but still, a USB drive disconnect is almost as easy.

May this would work better if the sanitizer allowed to check a part of the tree only, since I know the directory which is broken. I know that dirs also are encrypted and the structure is not the same, but there will be a mapping which folder in the crypted dir has the files.

If there is no easy way of fixing a remote only vault, then this whole approach is not feasable and I need to start looking for something else, like a cloud storage provider having end-to end encryption. Unfortunately, that means additional $ permanently and OneDrive I already have anyway.

Thanks again, J