Split index failed

Elastic Stack Elasticsearch
1

Hello,

I tried to split my index to more shard. My cluster has 3 node, the index currently have 1 shard and 1 replicas. I tried to split the shard, but I got a return with “shards_acknowledged : false”

PUT /my_source_index/_settings
{
  "settings": {
    "index.blocks.write": true 
  }
}

POST /my_source_index/_split/my_target_index
{
  "settings": {
    "index.number_of_shards": 2
  }
}

Also I found the target index is red and have a unassigned shard

2

What is the size of the index you are trying to split? How much disk space do you have left on the node holding the primary shard? What is the reason the red index can not be allocated if you use the cluster allocation explain API?

3

The index I try to split is 300gb, each node has 700gb. I can’t remember what is the wording exactly on the allocation explanation. It was something like primary and replicate cannot in the same node