What are the differences between the `*.tar` and `*.vhdx` backups of WSL?

  1. A *.tar backup is 30% smaller than the *.vhdx backup for the same WSL instance
  2. A *.vhdx backup is about 20 times faster (3 seconds vs 60 seconds) than the *.tar backup, but it could lead to the «The process cannot access the file because it is being used by another process» / «Wsl/Service/0x80070020» which will force you to wait for a minute.