The first time a young person deletes the database and runs away
The cause of this incident was Server Chan, but the ability to successfully restore to the most recent state (after midnight?) was also thanks to Server Chan.
Around midnight, after updating Server Chan, I restarted the server (the server backs up every time it starts). Then Zyf helped me log in.
I disabled Xbox verification and saw the backups in the worlds folder. According to Zyf, the archives are backed up once a day. However, due to the server frequently restarting, there were several extra backups. I was not happy about it, so I selected these backups, clicked delete-confirm. However, I was fooled. Damn VSCode selected the worlds folder when I expanded the worlds folder. So the entire worlds folder, including the archives and backups, were all deleted.
But I didn't notice and still started the server. I found it was a brand new world. It wasn't until I opened the worlds folder that I realized everything was gone.
However, being clever, I quickly found the powerful tool extundelete. By renting another server (thanks to the sponsor Zyf), mounting the original system disk as a data disk, and then executing
extundelete /dev/vdb1 --restore-file /root/worlds
Extundelete successfully scanned and pretended to recover two backups...
Then I found that only one block file was recovered, which was obviously no different from having nothing.
Later, I tried foremost and found that the recovered file names were unrecognizable, completely unusable. Because the block file names were also random numbers, there was no way to correspond them one by one with the recovered files.
Then I found that extundelete had a parameter to restore directories
extundelete /dev/vdb1 --restore-directory /root/worlds
But it kept saying "not such directory" after execution. After checking, I found out that I hadn't specified an output directory, adding -o shit fixed it.
The correct backup that was recovered, the most recent backup, the backup saved right after updating Server Chan, was actually buried in the first batch of unrecovered junk folders...
Copying the backup back, starting the server - OK.