Most dedup algos do compare the data. If you just use the hash, there's a very small chance of a hash collision causing file corruption / data loss. And dependi

Most dedup algos do compare the data. If you just use the hash, there's a very small chance of a hash collision causing file corruption / data loss. And depending on how common that block is, the corruption could affect a large number of files. Its a byte comparison.. so you still wouldn't use libreoffice to compare files.