SnapMirror relationships report a Preparing relationship status

Applies to

• ONTAP 9
• SnapMirror
• SnapVault
• Unified Replication
• Storage Virtual Machine Disaster Recovery (SVMDR)

Issue

• A XDP SnapMirror or SVMDR reverse resync takes much longer than expected
• It appears as if transfers are very slow, with low amount of data sent to the destination
• The source and destination storage systems are not highly utilized with lots of headroom in regards to performance
• The network is investigated between the sites and found to be functioning normally
• There is little to no data change on the source prior to the resync and before the last successful snapmirror update
• snapmirror show  or OnCommand System Manager reports a SnapMirror Relationship Status of  "Preparing" for a significant amount of time

ClusterA::> snapmirror show
                                                                         Progress
Source             Destination  Mirror  Relationship   Total             Last
Path         Type  Path         State   Status         Progress  Healthy Updated
-----------  ----  ------------ ------- -------------- --------- ------- --------
svmSource:volSource
             XDP   svmDest:volDest
                                Snapmirrored
                                        Preparing       98.17GB  true    01/01 12:00:00

• Both volume and SVM replication relationships can experience long periods of Preparing status after snapmirror resync
• The Preparing operation may run longer, and appear to transfer more data, than a typical update operation
• The delay in completing the Preparing operation will cause snapmirror resync of a volume snapmirror, or SVMDR, to appear slow.