MD5 Checksum doc changes

Author: shdeshpa07

backup_and_restore/application_backup_and_restore/installing/installing-oadp-aws.adoc

@@ -42,6 +42,7 @@ include::modules/oadp-self-signed-certificate.adoc[leveloffset=+2]
 include::modules/oadp-installing-dpa-1-2-and-earlier.adoc[leveloffset=+1]
 include::modules/oadp-installing-dpa-1-3.adoc[leveloffset=+1]
 include::modules/oadp-configuring-node-agents.adoc[leveloffset=+2]
+include::modules/oadp-configuring-aws-md5sum.adoc[leveloffset=+1]
 include::modules/oadp-configuring-dpa-multiple-bsl.adoc[leveloffset=+1]
 include::modules/oadp-enabling-csi-dpa.adoc[leveloffset=+2]
 include::modules/oadp-about-disable-node-agent-dpa.adoc[leveloffset=+2]

modules/oadp-configuring-aws-md5sum.adoc

@@ -0,0 +1,75 @@
+// Module included in the following assemblies:
+//
+// * backup_and_restore/application_backup_and_restore/installing/installing-oadp-aws.adoc
+
+
+:_mod-docs-content-type: PROCEDURE
+[id="oadp-configuring-aws-md5sum_{context}"]
+= Configuring the backup storage location with a MD5 checksum algorithm
+
+You can configure the Backup Storage Location (BSL) in the Data Protection Application (DPA) to use a MD5 checksum algorithm for both Amazon Simple Storage Service (Amazon S3) and S3-compatible storage providers. The checksum algorithm calculates the checksum for uploading and downloading objects to Amazon S3. You can use one of the following options to set the `checksumAlgorithm` field in the `spec.backupLocations.velero.config.checksumAlgorithm` section of the DPA.
+
+* `CRC32`
+* `CRC32C`
+* `SHA1`
+* `SHA256`
+
+[NOTE]
+====
+You can also set the `checksumAlgorithm` field to an empty value to skip the MD5 checksum check. 
+
+If you do not set a value for the `checksumAlgorithm` field, then the default value is set to `CRC32`.
+====
+
+.Prerequisites
+
+* You have installed the {oadp-short} Operator.
+* You have configured Amazon S3, or S3-compatible object storage as a backup location.
+
+.Procedure
+
+* Configure the BSL in the DPA as shown in the following example:
++
+.Example Data Protection Application
+[source,yaml]
+----
+apiVersion: oadp.openshift.io/v1alpha1
+kind: DataProtectionApplication
+metadata:
+  name: test-dpa
+  namespace: openshift-adp
+spec:
+  backupLocations:
+  - name: default
+    velero:
+      config:
+        checksumAlgorithm: "" # <1>
+        insecureSkipTLSVerify: "true"
+        profile: "default"
+        region: <bucket_region> 
+        s3ForcePathStyle: "true"
+        s3Url: <bucket_url>
+      credential:
+        key: cloud
+        name: cloud-credentials
+      default: true
+      objectStorage:
+        bucket: <bucket_name> 
+        prefix: velero
+      provider: aws
+  configuration:
+    velero:
+      defaultPlugins:
+      - openshift
+      - aws
+      - csi
+----
+<1> Specify the `checksumAlgorithm`. In this example, the `checksumAlgorithm` field is set to an empty value. You can select an option from the following list: `CRC32`, `CRC32C`, `SHA1`, `SHA256`.
+
+[IMPORTANT]
+====
+If you are using Noobaa as the object storage provider, and you do not set the `spec.backupLocations.velero.config.checksumAlgorithm` field in the DPA, an empty value of `checksumAlgorithm` is added to the BSL configuration. 
+
+The empty value is only added for BSLs that are created using the DPA. This value is not added if you create the BSL by using any other method. 
+====
+