It's possible only install Hadoop HDFS?
Absolutely possible. Don't think Hadoop as an installable program, it's just composed by a bunch of java processes running on different nodes inside a cluster.
If you use hadoop tar ball, you can just run NameNode and DataNodes processes if you only want HDFS.
If you use other hadoop distros (HDP for instance), I think HDFS and mapreduce come from different rpm packages, but it does harm to install both rpm packages. Again just run NameNode and DataNodes if you only need HDFS.