Batch account pool deletion stuck in resizing

Use the following steps to unblock and complete deletion of the stuck Batch pool.

1. Confirm the pool is in deleting/resizing state
   • Use Azure Portal or CLI to verify the pool state and that it has been stuck for a long time. Batch sets poolState to deleting and resizes nodes to zero before removing the pool object.
   • If deletion is taking longer than expected, Batch keeps retrying, but certain issues require manual fixes.
2. Check for resource locks on the Batch account and its resource group
   • In the Azure portal, go to the resource group that contains the Batch account.
     • Check Locks on the resource group.
       • If there is a lock (for example, Delete or ReadOnly), remove it.
       • This resolves Cause 1a where the Batch account’s resource group is locked and prevents delete operations.
   • Then open the Batch account resource.
     • Check Locks on the Batch account itself.
       • If present, remove the lock.
       • This resolves Cause 1b where the Batch account is locked.
   • After removing locks, wait ~20 minutes and re-check the pool; if still present, retry deletion.
3. If the pool uses a virtual network, check locks and dependencies on Batch-created network resources
   • When a pool is created in a virtual network, Batch automatically creates:
     • Network Security Group (NSG)
     • Public IP address
     • Load balancer
   • Deleting or resizing the pool to zero requires Batch to delete these resources.
   a) Check for resource locks on the VNet resource group
   • Go to the resource group that contains the virtual network used by the pool.
   • Check Locks on that resource group.
     • If there is a lock, remove it.
     • This resolves Cause 2a where extra networking resources in the resource group are locked and block deletion of the Batch-created load balancer.
   • After removing locks, wait ~20 minutes for Batch to complete deletion.
   b) Check for external dependencies on Batch-created resources
   • In the same resource group, locate the Batch-created NSG, public IP, and load balancer (names typically include azurebatch-cloudserviceloadbalancer or azurebatch-cloudservicenetworksecuritygroup).
   • If the NSG is associated with other subnets or NICs outside the Batch pool, or if other resources depend on the Batch-created IP or load balancer, Batch cannot delete them and the pool deletion will hang.
     • For example, an activity log entry like:
       • Network security group ... cannot be deleted because it is in use by ... virtualNetworks/<vnet>/subnets/<subnet>
       • indicates Cause 2b.
   • Fix by disassociating these dependencies:
     • Disassociate the NSG from any subnet or NIC that is not part of the Batch pool (see associate or dissociate a network security group to or from a subnet or network interface).
   • After removing dependencies, wait ~20 minutes; Batch should finish deleting the pool and its network resources.
4. Retry or monitor deletion via CLI/SDK
   • If needed, explicitly request deletion again:
     • Azure CLI:

              az batch pool delete --pool-id <pool-id>
       

     • Or via Python SDK PoolOperations.delete(pool_id=...).
   • Note: If the pool is already in deleting state, any further Update/Patch/Delete calls will fail with HTTP 409 PoolBeingDeleted until the underlying issues (locks/dependencies) are resolved.
5. If deletion still does not complete
   • After removing all locks and external dependencies and waiting sufficient time, if the pool remains stuck, check for broader conditions mentioned for pool deletion failures:
     • Ensure Microsoft.Batch resource provider is still registered in the subscription.
     • For user subscription mode accounts, ensure Microsoft Azure Batch still has Contributor or Owner role on the subscription that contains the pool.

Once all locks and external dependencies are cleared and Batch has required permissions, the stuck pool should automatically complete deletion within about 20 minutes; if not, re-issuing the delete request after fixes should succeed.

References:

• Azure batch pool deletion failure
• Azure Batch pool and node errors
• Command az batch pool delete
• Command az batch pool resize
• PoolOperations Class