Snapshot process stuck in one last shard

Hi,

I'm trying to take a snapshot into a repository that i previously created.
I want to snapshot 3 indices, for the second time (I've already done the first snapshot which succeeded), but after some new docs injected i want to take another snapshot into the same repository.

The problem is that the snapshot process got stuck for more than 4 hours with one last shard (see below for detailed snapshot status. Shard 4 of index publication)

I am using Elasticsearch 2.2 and here is the request i used to take the first and second snapshots :
PUT /_snapshot/elastic_backup/snapshot_1
{
"indices": "family,publication,patent",
"ignore_unavailable": false,
"include_global_state": false
}

Here is the response when i ask for the status (GET /_snapshot/elastic_backup/_status) :
All shards are on "stage":"DONE" but this one below :

"4": {
"stage": "STARTED",
"stats": {
"number_of_files": 210,
"processed_files": 102,
"total_size_in_bytes": 62383548380,
"processed_size_in_bytes": 31735859207,
"start_time_in_millis": 1457338235435,
"time_in_millis": 0
},
"node": "_fYrGcp5RzODSabF9KT02Q"
},

Any idea why this is happening ? I have enough disk space left.
Is there a way to "restart" only the stuck shard or should i delete the entire snapshot and retake it ?

Thank you for your help.

Were you able to solve this? I seem to be having same problem.

Unfortunately i did not solve this problem. I had to abort the snapshot process and restart it again...
If you have a file-system level snapshot/restore process, i encourage you to use it instead of the software one embedded with ES.

Can you please explain what you mean by file-system level? external to ES?

Yes, Exactly.