My old laptop suddenly became very slow many years ago. top told me it was 99% in wait status. It was the hard disk failing. I think it was trying to read again

My old laptop suddenly became very slow many years ago. top told me it was 99% in wait status. It was the hard disk failing. I think it was trying to read again and again some bad sector. Shutdown. Bought a new HDD, restored from backup, solved. BTW, that new HDD failed with a bad clack clack clack noise years later. Backups saved me again.