Update en/restore-from-ebs-snapshot-across-multiple-kubernetes.md

en/restore-from-ebs-snapshot-across-multiple-kubernetes.md

@@ -37,6 +37,9 @@ Before restoring a TiDB cluster across multiple Kubernetes clusters from EBS vol
 > The EBS volume restored from snapshots might have high latency before it is initialized. This can impact the performance of a restored TiDB cluster. See details in [Create a volume from a snapshot](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-creating-volume.html#ebs-create-volume-from-snapshot).
 > 
 > It is recommended that you configure `spec.template.warmup: sync` to initialize TiKV volumes automatically during the restoration process.
+> You can specify the warmup strategy for TiKV data volumes. Set `spec.template.warmupStrategy: fio` to use `fio` linux command to warmup data volumes, set to `spec.template.warmupStrategy: fsr` to enable FSR for data volumes before start TiKV, and set to `spec.template.warmupStrategy: hybrid` to use file scanner to warmup data volumes. `hybrid` is the default option.
+
+If you choose `fsr` as the warmup strategy, you need to grant permissions of `ec2: EnableFastSnapshotRestores`, `ec2: DisableFastSnapshotRestores` and `ec2: DescribeFastSnapshotRestores` to the IAM role. And you also need to increase the EBS service quota of `Fast snapshot restore` to at least the number of TiKV nodes.
 
 ## Restore process