Today I got the second time a similar problem with my Ubuntu. The first time it was in September, the second one is today. For the first time, it was updated by itself to the new Ubuntu version and deletes all my files. So, I was working and then find myself, that I didn't see some folders. I restart the notebook and see the completely new OS, new version and without my files. It was a lot of free space, so all my files were deleted. And I didn't solve that problem. I have lost all my data. That time I thought, I have allowed installing a new version of Ubuntu, but I didn't do this.
Yesterday I start to work on my notebook (the OS was reinstalled by me on another HDD), run the IntellijIdea, see the project and start to work. Then I see, the folder "Documents" marked by grey and I cannot enter it. Then I see, that the project files in IntellijIdea are file by file are dissapearing and the project is completely new, as it was just created. Then I switched off the notebook and connect this HDD to another Ubuntu computer - It cannot be viewed. I connect it to Win10 computer - it cannot be viewed. I connect to Mint computer and I see, that the folder "Documents" exists, but it has an only blank project for IntellijIdea. So, no any my folders or files. But I found a folder without a name and enter it - it was my old "Documents". So, I gave the name for it and copied all my needed files to separate HDD. I was lucky this time.
Can you please help me - what is this? How it is possible, what to do for not having this in the future? I have a different types of log files. Which ones can help to understand, what was the problem?
Additional information: 1. The file /etc/fstab:
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
/dev/mapper/ubuntu--vg-root / ext4 errors=remount-ro 0 1
/dev/mapper/ubuntu--vg-swap_1 none swap sw 0 0
- The result of lsblk | grep -v loop:
punisher@punisher-HP:~$ lsblk | grep -v loop
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 298,1G 0 disk
└─sda1 8:1 0 298,1G 0 part
├─ubuntu--vg-root 253:0 0 297,1G 0 lvm /
└─ubuntu--vg-swap_1 253:1 0 980M 0 lvm [SWAP]