a very strange glitch

[Skaperen]

edit: the prefix should be Xubuntu, not Kubuntu. sorry, and edit doesn't let me fix that.

this afternoon, i renamed a username and its groupname and added about 7.5 GB of files to it. i used commands usermod and groupmod to do this, among other things. i renamed user1009 to gene. i looked at /etc/passwd and /etc/group and verified everything had worked OK. then i ran rsync to copy about 93000 files to its home directory under its new name. that worked OK. it basically copied /home/pdh to /home/gene (the new name). i then ran chown -R gene:gene /home/gene to set up the correct new ownership. i ran ls -l /home/gene and it looked OK. i did not check every single file.

then i modified the shortcuts file on all other users so that Alt+G would run /usr/bin/dm-tool switch-to-user gene to tell lightdm to switch to that user. that is my method of switching between users. it works.

i was able to successfully switch to user gene by pressing Alt+G. i rebooted as a cheap way to get all users to load their shortcuts, again, alt it still worked. then i paused to eat dinner.

when i was done with dinner i decided to do an upgrade. for consistency i always reboot before the upgrade (so only admin is logged in) and reboot twice afterwards, so any steps that need to run after a reboot can and so my custom setup script has a fresh system to run from.

then i discovered that everything in /etc had reverted back to its original contents. user gene did not exist, as far as this system knew. i keep a directory of symlinks to user home directories in /homes because home directories are scattered around over 3 different file systems. i had added the symlink for gene but it was now gone. all the logs in /var/logs show there was never a user named gene.

but /home/gene still exists and stlll has the 7.5 GB of files i had copied with rsync. all users still have the shortcut for gene which obviously won't do much good right now.

i was in the room the entire time, never leaving it for a second. no one messed with the laptop (they are not allowed to unless i grant permission on a case by case basis).

other scans look like this afternoon never happened except that last does show the reboot i did this afternoon at about the right time. logs show no I/O errors today and i saw no strange messages.

any idea what might have done this besides an invisible evil maid?

any idea what i could check to see what caused this?

it looks like the entire root file system (about 64 GB and has /, /etc, and /var) reverted to an old copy while /home (about 900GB) did not. i am running Xubuntu 18.04.5 LTS previously upgraded a few days ago. file system types are all ext4.

[TheFu]

Two disks connected to the system? Perhaps 1 was cloned from the other?