Shards locating on one node

Hi guys.
Few days ago I added a new node to my ES Cluster.
And after that all my shards start to locate only on this new node!

Please gyus, give me some advice where I need to look?

New node has ES 1.7.1 instead 1.5 in the cluster. here it's said that I need one version everywhere? Is that true?

I assume you mean shards of new indexes?
When an index is created elasticsearch makes sure that shards that were created on a newer version node will only ever be allocated on other nodes that have a version at least as up-to-date as the one where is was created. So depending on where a shard was created it might never be able to relocate anywhere else and also replicas will not be assigned on lower version nodes. Upgrading the other nodes will fix this in this case.
In addition, it looks like data2 and data3 are running low on disk space which might be another reason for the decision to allocate the shards on the new node in the beginning.

I upgrade whole cluster to es 1.7
But new shards (prim or replica ) allocated only on new cluster. Now it looks like

And why some shards unaasigned? :frowning:

This does seem to be a duplicate of: Space ending in ES cluster