Windows 10 SSD Unplugged and Data Lost

[Nerdyguy]

I lost all my data because apparently external ssd's are not hot swappable. Here is how it went: I installed Windows 10 on the SSD and moved all files from the HDD to the SSD while running the OS on the HDD. Then I put the SSD in the laptop hard drive space and booted up, but there were no files available. When I went back to the HDD and booted with that, I saw the files in the SSD again. I thought it might be a problem with permissions or Windows fast boot so I disabled it and unplugged the usb external hard drive converter that the SSD was in to make sure that shutting down wouldn't affect my ability to view the files. However, when I booted back up with the SSD, a bsod came up with a file system error, so the OS went through a startup repair process and restored some system files automatically. When I finally saw it boot up, expecting to be able to see the files, an error came up that said "We can't sign into your account". When I looked in "This PC", I saw that the SSD had very little data on it and all of the data I had loaded onto it previously was gone. It had essentially restored to the way it was right before I had started moving the files to it from the old drive, albeit the account error. It still has the error at the moment.

What I want to know more than anything else is: why did the data get removed, and why does unplugging an external SSD corrupt its file system?
Other than that, any advice on the account error would be appreciated.
Thanks.

 

[Neemobeer]

Did you properly eject the disk? Windows does a lazy write so if it wasn't finished writing data then that would explain the missing data.

 

[Nerdyguy]

Did you properly eject the disk? Windows does a lazy write so if it wasn't finished writing data then that would explain the missing data.

I got rid of the account error, but as to whether I properly ejected the disk, I right clicked on the SSD icon but I didn't see an eject option so considering that I had finished transferring the data to it and wasn't using it at the moment, I decided to unplug the usb-sata converter directly, not expecting anything bad to happen. The data should not have been deleted at that moment; it should have been minorly corrupted at the worst, and so I was shocked to find out that the startup repair process actually had to delete it in order to restore the OS to working condition.

 

[Neemobeer]

Just because there are place holders for the files, the data may not have finished writing

 

[Neemobeer]

You may see delayed write errors in the eventlog if writing was interrupted by unplugging the drive prematurely. You can also go into device manager for the given device and remove the 'write caching' feature' to have it write data immediately. I would not recommend this for internal devices as it can affect performance.

 

[Nerdyguy]

Just because there are place holders for the files, the data may not have finished writing

It took a while to transfer, and I waited until the window detailing the processes closed. Also, as I said, I rebooted the HDD and the files were still there. I even opened a couple of them to make sure. It was AFTER this reboot that I unplugged the SSD.

 

[Neemobeer]

Still doesn't mean it was necessarily written. I would run fsutil transaction list if you have pending transactions then it didn't finish writing

 

[Nerdyguy]

Still doesn't mean it was necessarily written. I would run fsutil transaction list if you have pending transactions then it didn't finish writing

I am not near the computer at the moment, but it couldn't have been that because even the files I opened were gone. I didn't just lose some data, I lost all of it, after the computer spent hours transferring it to the other drive. There should have been something left.

 

[Neemobeer]

You may have corrupted the MFT, you can try using a data recovery tool such as GetDataBack, testdisk or Recuva

 

[Nerdyguy]

You may have corrupted the MFT, you can try using a data recovery tool such as GetDataBack, testdisk or Recuva

I actually did try Recuva, but it didn't recover more than 20 files, none of which were of any use to me.

Does the startup repair process have to perform a system restore in order to uncorrupt the filesystem - or the MFT? I'm rather surprised that it would go through such a process without first alerting or asking the permission of the user. I'm especially surprised that it would have to go to such lengths considering that I only transferred personal files; I never tampered with system files. Is it likely that the MFT was being edited and that system file entries were being modified or rearranged to make way for personal file entries?