There is no index target to point to Creating one now

Hey @totemz

Can I ask how you configured your index set? Also someone had a simialer issue with graylog config file. Ther eupgrade wrote over the old file shown here

Check you configration again make sure the path.data: /var/lib/opensearch is correct.
Here are couple more commands for troubleshooting

#### See if you can find the  old index set's ###
curl -XGET http://localhost:9200/_cat/indices?v
curl -XGET http://localhost:9200/_cluster/allocation/explain?pretty