OpenSearch - Instance type migration stop in "Step 3 of 4: Copying shards to new nodes"

Question

I reconfigured my OpenSearch cluster from T2 to C5 instance type.
The migration remains in "Step 3 of 4: Copying shards to new nodes" status for 2 days.
Any idea to escape from this situation?

Answer

Hello Patrick, I recommend to open a support case to resolve the issue. Do you have [any support plan](https://aws.amazon.com/premiumsupport/plans/?nc=sn&loc=1) for you account where the OpenSearch cluster runs? When opening a support case, make sure to open it from the same account as your OpenSearch cluster. Also, share the OpenSearch domain ARN and the issue description in the support case correspondence.

> Note: If your cluster is stuck in the "Processing" state for more than 24 hours, then your cluster needs manual intervention. Also, if you haven't made any configuration changes but the node count is higher than expected, then a software patch might be in progress.

- https://aws.amazon.com/premiumsupport/knowledge-center/opensearch-domain-stuck-processing/?nc1=h_ls

OpenSearch - Instance type migration stop in "Step 3 of 4: Copying shards to new nodes"

Relevant questions

OpenSearch cluster stuck in creation

Failure to start warm migration

Which Opensearch instance type to choose for a new webapplication with little data?

Opensearch 3 node cluster's diskspace was upgraded from 500GB to 600GB. The copying of shards to new nodes became stuck.