@resuni,
If you’re on ZFS, BTRFS, EBS, or use LVM, you can use snapshots to make this process quicker.
Here is the patch for the fix with comments from Oracle
Based on Oracle’s comments, my guess is that since Xtrabackup “cleans” the state of InnoDB before starting MySQL 8, the issue isn’t seen. But when you do a direct 5.7->8, the incorrect state from 5.7 remains in cache and mysql 8, on first start, did not clean that cache properly.
