Indexes on status unassigned and initializing - HOW TO FIX?

Good night,

We've set an elasticsearch cluster with two nodes, which are receiving information from a logstash instance.

The index information as well as shards are stored on GPFS filesystem

we've recently suffered a serious problem with the GPFS environment, due to a problem with the available space the elasticsearch application was stuck the whole weekend

once we've fixed this space problem, the application tried to start to process the waiting indexes ans shards

We've detected that most of the indexes for those days are stuck on INITIALIZING status, after review the whole set of indexes and shards we've found that there are a big bunch of shards that are on UNASSIGNED status

Could you please help us to stabilize our environment and let us know what is the path that we need to follow in order to fix our current situation

Kind Regards