How to backup ES version 1.4.5 + Upgrade options

Hi,

I'm a newbie with ES, still having issues understanding it.

What are my options to backup my ES version 1.4.5?
Can I just copy + paste the elasticsearch.yml file and data folder (/var/lib/elasticsearch/*) to another location?

Also, can I upgrade to the latest stable community version or should i upgrade to a later versions in steps? will I need to upgrade Java or OS as well? (ES running on Ubuntu 14.04.4 LTS) with:
java version "1.8.0_74"
Java(TM) SE Runtime Environment (build 1.8.0_74-b02)
Java HotSpot(TM) 64-Bit Server VM (build 25.74-b02, mixed mode)

Thanks,
B

With only one node and no operation on the cluster, yes.

Look at snapshot/restore feature.

If you want to upgrade to 5.2, you may want to use reindex from remote feature instead.