Dell PowerVault MD3820f - Manual (Page 209)

Remote Replication Requirements And Restrictions
To use the standard Remote Replication premium feature, you must have:
• Two storage arrays with write access and both these storage arrays must have sufficient space to
replicate data between them.
• Each storage must have a dual-controller Fibre Channel or iSCSI configuration (single-controller
configurations are not supported).
• Fibre Channel Connection Requirements — You must attach dedicated remote replication ports to a
Fibre Channel fabric environment. In addition, these ports must support the Name Service.
• You can use a fabric configuration that is dedicated solely to the remote replication ports on each
RAID controller module. In this case, host systems can connect to the storage arrays using fabric.
• Fibre Channel Arbitrated Loop (FC-AL), or point-to-point configurations, are not supported for array-
to-array communications.
• Maximum distance between the local site and remote site is 10 km (6.2 miles), using single-mode fibre
Gigabit interface converters (GBICs) and optical long-wave GBICs.
• iSCSI connection considerations:
– iSCSI does not require dedicated ports for replication data traffic
– iSCSI array-to-array communication must use a host-connected port (not the Ethernet
management port).
– The first port that successfully establishes an iSCSI connection is used for all subsequent
communication with that remote storage array. If that connection subsequently fails, a new
session is attempted using any available ports.
Restrictions On Using Remote Replication
• RAID level, caching parameters, and segment size can differ between replicated virtual disks.
• The secondary virtual disk must be at least as large as the primary virtual disk.
• Only standard virtual disks can be included in a replication relationship. Snapshot (Legacy) virtual
disks, snapshot virtual disks, and thin virtual disks cannot be used.
• A primary virtual disk can be a source virtual disk or a target virtual disk in a virtual disk copy. A
secondary virtual disk cannot be a source virtual disk or a target virtual disk unless a role reversal is
initiated after the copy has completed. If a role reversal is initiated during a Copy in Progress status,
the copy fails and cannot be restarted.
• A virtual disk can be included in only one replication relationship.
• A virtual disk participating in a copy request cannot be a replicated secondary virtual disk.
Setting Up Remote Replication
Setting up Remote Replication between local and remote storage arrays using MD Storage Manager
consists of the following:
• Activating the Remote Replication premium feature on both the local and remote storage arrays
• Creating a remote Replication group on the local storage array
• Adding a replicated pair of virtual disks to the Remote Replication group
Activating Remote Replication Premium Features
Activating Remote Replication automatically reserves specific ports on each RAID controller module for
data replication. After the port is reserved, any non-replication related I/O request to that port is rejected.
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