Add recommendation for vsClass's annotation

Incorporating QE suggestion

SME feedback

Author: apurvabhide17

backup_and_restore/application_backup_and_restore/backing_up_and_restoring/oadp-backing-up-pvs-csi-doc.adoc

@@ -34,8 +34,8 @@ driver: <csi_driver>
 deletionPolicy: <deletion_policy_type> <3>
 ----
 <1> Must be set to `true`.
-<2> Must be set to `true`.
-<3> OADP supports the `Retain` and `Delete` deletion policy types for CSI and Data Mover backup and restore. For the OADP 1.2 Data Mover, set the deletion policy type to `Retain`.
+<2> If you are restoring this volume in another cluster with the same driver, make sure that you set the `snapshot.storage.kubernetes.io/is-default-class` parameter to `false` instead of setting it to `true`. Otherwise, the restore will partially fail.
+<3> OADP supports the `Retain` and `Delete` deletion policy types for CSI and Data Mover backup and restore. 
 
 .Next steps
 

modules/oadp-backing-and-restoring-from-cluster-to-cluster.adoc

@@ -15,7 +15,7 @@ In general, you back up data from one {product-title} cluster and restore it on
 
 .Procedure
 
-* Make the following additions to the procedures given for your platform:
+. Make the following additions to the procedures given for your platform:
 
 ** Ensure that the backup store location (BSL) and volume snapshot location have the same names and paths to restore resources to another cluster.
 ** Share the same object storage location credentials across the clusters.
@@ -26,8 +26,14 @@ In general, you back up data from one {product-title} cluster and restore it on
 ----
 $ velero backup create <backup_name> --default-volumes-to-fs-backup <any_other_options>
 ----
-
++
 [NOTE]
 ====
 In OADP 1.2 and later, the Velero Restic option is called `file-system-backup`.
 ====
+
+[IMPORTANT]
+====
+Before restoring a CSI back up, edit the `VolumeSnapshotClass` custom resource (CR), and set the  `snapshot.storage.kubernetes.io/is-default-class parameter` to false. 
+Otherwise, the restore will partially fail due to the same value in the `VolumeSnapshotClass` in the target cluster for the same drive.
+====