Is it safe to delete Elasticsearch indices from the file system?
<p>When we restart our single node Elasticsearch instance, it starts allocating it's shards.</p>

<p>The allocating of the shards requires more memory then available which is causing the instance to stop working.</p>

<p>We tried to quickly disable the allocation when the instance starts by executing follow query:</p>

<pre><code>PUT /_cluster/settings
{
    "transient" : {
        "cluster.routing.allocation.enable" : "none"
    }
}
</code></pre>

<p>This call however time-outs because it's busy trying to allocate the shards (with too many resources for it).</p>

<p>The option to increase resources (memory/CPU) is not possible. </p>

<p>The only option that we were left with was deleting the majority of the indices on the file system (when the Elasticsearch instance is down) on the following path:</p>

<pre><code>/var/lib/elasticsearch/&lt;id&gt;/nodes/0/indices/
</code></pre>

<p>Is this considered to be safe? Is this a proper solution? Are there any other solutions like updating the configuration to disable shard allocation?</p>