elasticsearch - what to do with unassigned shards

Question

my cluster is with yellow status because some shards are unassigned. what to do with this?

I tried set cluster.routing.allocation.disable_allocation = false

Answer 1

The first 2 points of the answer by Alcanzar did it for me, but I had to add

"allow_primary" : true

like so

curl -XPOST http://localhost:9200/_cluster/reroute?pretty -d '{
  "commands": [
    {
      "allocate": {
        "index": ".marvel-2014.05.21",
        "shard": 0,
        "node": "SOME_NODE_HERE",
        "allow_primary": true
      }
    }
  ]
}'