This probably relates your other recent post:
Hi,
Relatively simple question about the configuration of elasticsearch with respect to specific data security.
Are there any possibilities to configure an elasticsearch cluster so that in case of a power failure there are no additional data losses?
What security models when not all nodes have redundant power supply?
Is there anything we can do?
Of course backup is backup. But I'm looking for a quick solution in elasticsearch.
Looks like your storage system does not, in fact, implement fsync() correctly.
What's the whole response from the allocation explain API? It looks like all copies of this shard are broken. Does this index have replicas?