Identifying corrupt indices

Hi All,

We have a single node elasticsearch having good amount of storage. It has been working fine since last one year and suddenly stopped working, seems due to data corruption.
I can see few indices, for which state is in red by using api : https:///_cat/indices

I have few questions:

Have all the red status indices corrupted or few of the indices are causing issue?

Is there a way to identify the corrupt indices and can these be fixed?

Regards,
Neeraj Bhagat

If you have a single node and no replicas any data in corrupt shards is probably lost.