Dell PowerStore Protecting Your Data

Replication summary

The following table summarizes the various attributes of replication (synchronous and asynchronous) and metro.

Table 1. Replication and metro - SummaryThe first column lists various replication attributes and the next three columns describe this attributes for asynchronous replication, synchronous replication, and metro, respectively.
Attribute	Asynchronous Replication	Synchronous Replication	Metro
Supported type	Block and file	Block and file	Block
Storage resources	Volumes, volume groups, thin clones, NAS servers, vVols	Volumes, volume groups, thin clones, NAS servers	Volumes, volume groups
Replication type	Asynchronous	Synchronous	Synchronous
Target RPO	Fixed value 5 min - 24 h	0	0
Host access	Active/Passive. Requires a failover	Active/Passive. Requires a failover or RTO>0	Active/Active ALUA path change
Host protocols	SCSI, NVMe	SCSI, NVMe	SCSI
Block WWN/NQN	Different	Different	Same WWN on both ends
Witness	No	No	Yes
RTT/Distance	Not applicable	5milliseconds	5milliseconds*
Performance impact on host access	Minimal impact depending on sizing and workload	Adds additional latency (mirror round-trip-time)	Adds additional latency (mirror round-trip-time)
Snapshot replication	Replication of block snapshots on source. Does not support snapshot replication for File.	Near identical block snapshots. Does not support snapshot replication for File.	Near identical snapshots
Failover test	Yes (for example, file, using a clone)	Yes (for example, file, using a clone)	Not applicable
Conversion synchronous <-> synchronous	Allowed for block resources. Not supported for file.	Allowed for block resources. Not supported for file.	Not supported
Recovery snapshot	Common base at each replication cycle	Supported when paused	Not supported
NDU	Replication is paused during NDU	Active sessions continue	Active sessions continue