How to solve the problem primary shard is not yet active

How could I resolve this problem?

index                                       shard prirep state          docs   store ip        node  
new_gompute_history_2015-10-23_10:10:26     2     p      INITIALIZING       Alyosha Kravinoff 
new_gompute_history_2015-10-23_10:10:26     2     r      UNASSIGNED

Because I have enough space in the disk to save data in ES (more than 85% of capacity) but when I want to reallocathe this shard I cannot do it and the message that I obtain is by:

[NO(primary shard is not yet active)]

Could some body tell me something about this?

Thanks in advance.

I have this configuration in elasticsearch.yml

index.routing.allocation.disable_allocation: false

But I continue with the same problem.