Disk errors causing Dropbox to delete files

[BDub]

Hi community,

I recently noticed some unexpected 'deleted files' activity on my account.

Initially I assumed it was user error, that I’d mistakenly deleted these files somehow. So I restored the missing files, and based on this assumption left the matter there.

Then it happened again.

It turns out that one of the PC’s I have my Dropbox installed on has been experiencing some disk failure on a secondary internal HDD (mounted as F:\)

On this particular PC, Dropbox had been set up, with my two accounts (a Business Standard and a Personal Basic), pointing to a non-standard location for the Dropbox Folders (ie. F:\username\Dropbox (Personal)\ and F:\username\Dropbox (Business Name)\ ) – homed on this now failing second disk.

From my understanding, it appears that Dropbox has be interpreting this failing disc’s errors – low-level disc access failures -  as user level file/folder deletes.

In other words as this disc has been silently failing and effectively ‘deleting’ files, Dropbox has interpreted this as user actions and synced the corresponding deletes to the upstream repository.

As a result I have lost a lot of data. All in very random locations throughout the Dropbox file hierarchy.

I have been able to recover all the data from the linked Business account, but I did not catch the problem in time to recover all the lost data from my personal account (30 days history).

Q) Has anyone experienced anything similar? If so what did they do?

Q) Is this known and intended Dropbox behavior?  - Surely Dropbox should have some defense against this circumstance? Or have I misunderstood what Dropbox can be relied on for – ie. data backup/protection?

Q) If I upgrade my Personal Basic account to Professional, will this unlock 180 days of deleted file history, or have I permanently lost the data that I did not recover in time?

Thanks in Advance.

Ben

[Megan]

Hi @BDub, welcome to the Dropbox Community! 

What you described is expected when the app is pointing to a non-standard location.

If the drive is ever disconnected from the computer while Dropbox is running, there is a small chance that the Dropbox software will start deleting files before realizing that the entire drive has been removed. 

Accordingly, any issues affecting the hard drive, such as a hard drive failure or difficulty writing to the hard drive, could have caused the deletions.

I hope this clarifies. 
 

[RSpencer]

Hi Megan,

I would just like to clarify your response to @BDub: If I understand correctly, dropbox, which is (among other things) a backup tool, is expected to delete the remote copies of files if there is a drive error. I.e. In exactly the circumstance where a backup is most crucial, it is expected to delete the backup. Is that correct? Not just a known issue, but expected behaviour?

I recently had a similar issue: a failing drive leading to dropbox purging most of my account, both on the cloud and on my other connected computer. I was able to fix it using the 30 day restore feature, but I was hoping there was a way to avoid this issue altogether. 

Also, you specified that this is expected when dropbox is pointing to a non-standard location. Would this not be an issue for the standard location? If that is the case, I am curious why. I assumed that if dropbox cannot has issues seeing the difference between a deleted file and an I/O error, that would extend to any location, but I don't know the inner workings of dropbox.

[Jay]

Hi @RSpencer, Dropbox is primarily a syncing service instead of a backup service. This means that any changes to files, including deletions, would be synced to the site. 

This would occur on any location that the Dropbox folder is located. I/O errors would also mean that files are unreadable, meaning they 'don't exist' according to the system, so the files would be deleted from the Dropbox site. There isn't any way to prevent these types of errors from deleting files from your account. 

If the Dropbox folder is located on an external drive, and that drive is disconnected while the app is running, this could result in data deletion. On the rare instance that an internal drive is disconnected (due to other hardware issues), this can also occur.

If you need any more details, feel free to message back.

[dyk1]

Hi, I had the exactly same problem. An internal hard drive of PC, synced with dropbox, failed a couple days ago and I released that most of my dropbox contents have been erased in other PC with sync. Very scary! I think it needs to be check how this can be happening. 

[Walter]

Hey @dyk1, sorry to hear about this.

Can you please take a look at your events page and let us know how exactly those deletions are logged there? 

Any additional information you can share about the incident would be much appreciated. 

[Bob Sacamano]

I also had this happen to me recently. Seriously concerning when I though my files were made safe with Dropbox. Luckily, I caught it before the retention period expired. But if I hadn't, we could have lot invaluable data forever without even knowing about it. 

This makes me seriously question whether ANY cloud sync or backup should be used. If you are using cloud you need a one-way only upload to a service that won't delete anything uploaded for any reason... work with local files only and backup to a local SSD only.