Home > Storage > PowerStore > Data Protection > Dell PowerStore: Metro Volume > Failure Scenario – Replication link failure
In this scenario, all replication links between the two arrays have failed. However, both arrays remain online and can communicate with the witness.
Each metro session on Array 1 and Array 2 sends a fracture request to the witness. By design, the fracture requests from the preferred volumes reach the witness before those from the non-preferred volume. Consequently, the preferred volumes win and stay online, while the non-preferred volumes are taken offline. For more information about this witness communication flow design, see Communication flow – fracture in the Witness section.
On Host 1
metro-vol-001 sdaz active 50 active/optimized array1-nb-iom0-p1
metro-vol-001 sdbd active 50 active/optimized array1-nb-iom0-p0
metro-vol-001 sdad failed 10 unavailable array2-na-iom0-p0
metro-vol-001 sdbf failed 10 unavailable array2-nb-iom0-p1
metro-vol-001 sdbl failed 10 unavailable array2-nb-iom0-p0
metro-vol-001 sdj failed 10 unavailable array2-na-iom0-p1
metro-vol-001 sdc active 10 active/non optimized array1-na-iom0-p0
metro-vol-001 sdh active 10 active/non optimized array1-na-iom0-p1
On Host 2
metro-vol-001 sdaw failed 50 unavailable array2-nb-iom0-p0
metro-vol-001 sdm failed 50 unavailable array2-nb-iom0-p1
metro-vol-001 sdaa failed 10 unavailable array2-na-iom0-p0
metro-vol-001 sdt failed 10 unavailable array2-na-iom0-p1
metro-vol-001 sdaq active 10 active/optimized array1-nb-iom0-p0
metro-vol-001 sds active 10 active/optimized array1-nb-iom0-p1
metro-vol-001 sdb active 10 active/non optimized array1-na-iom0-p0
metro-vol-001 sdd active 10 active/non optimized array1-na-iom0-p1
Metro and Witness status on Array 1 and Array 2
Recovery of replication links
In the absence of a witness, the Polarization mechanism would have taken the non-preferred volumes on Array 2 offline. However, because all VMs run on the hosts that retain access to the preferred volumes, they continue to operate without interruption.