OpenSearch Docker Container Won't Start

How to fix it

// try these in order, the most common fix is first

1. FIX 1Set a strong admin password

   Copy steps
   1. 01Export OPENSEARCH_INITIAL_ADMIN_PASSWORD or put it in a .env next to docker-compose.yml
   2. 02Use 8+ characters with upper, lower, number and special character
   Did this fix it? Yes No

2. FIX 2Raise vm.max_map_count

   Copy steps
   1. 01Linux: sudo sysctl -w vm.max_map_count=262144 and persist in /etc/sysctl.conf
   2. 02Docker Desktop: set it inside the Docker VM or WSL docker-desktop distro, not in the container
   Did this fix it? Yes No

3. FIX 3Read the logs

   1. 01docker logs <container> will show which check failed
   Did this fix it? Yes No

Symptoms

Container exits right after start; logs mention a missing or weak admin password, or 'max virtual memory areas vm.max_map_count [65530] is too low'.

Why it happens

• C-01No OPENSEARCH_INITIAL_ADMIN_PASSWORD set (required since 2.12)
• C-02Password too weak for the default policy
• C-03vm.max_map_count too low on the host or Docker VM
• C-04Insufficient memory for the heap

// this guide also covers

• opensearch docker not starting
• opensearch initial admin password
• opensearch vm.max_map_count too low

Other OpenSearch errors

• OpenSearch Cluster Status Red
• OpenSearch Cluster Status Yellow
• OpenSearch Unassigned Shards
• OpenSearch High JVM Memory Pressure
• OpenSearch OutOfMemoryError and Circuit Breaker
• OpenSearch Exceeded Maximum Shard Limit
• OpenSearch Index Read-Only: Disk Watermark and ClusterBlockException
• OpenSearch 429 Too Many Requests