Dell EMC defines MTrees as logical partitions of the file system and they are identified by unique names. MTrees are used to create (protocols can be mixed, except VTL):
- DD Boost storage units
- VTL pools
- NFS/SMB shares
MTrees allow granular management of snapshots and quotas. Quotas apply only to logical data written to an MTree.
There is a fixed amount of MTrees that can be created on a Data Domain system and it depends by the model and DD OS version.
|DataDomain system||DD OS version||Configurable MTrees||Concurrently Active MTrees|
Data Domain Replicator is a technology that allows replication between two (or more) Data Domain systems. The replication process is network-efficient as no data re-hydrate happens when transferring data between two systems.
To reduce bandwidth usage, Data Domain Replicator performs two levels of deduplication:
- local – determines the unique segments that must be replicated over WAN
- cross-site – it further reduces bandwidth requirement when multiple systems are replicating to the same target (many to one architecture)
Data Domain Replicator is a licensed feature.
Replication always involves at least two Data Domain systems, identified as source and destination and each system can be either source and destination (cross-replication). The process is always asynchronous.
A Data Domain can be set up for different kind of replication, such as:
- Directory – replication based on single directory (the smallest entity within an MTree)
- Collection – entire Data Domain content
- MTree – entire MTree replication, including all subfolders
Watch the load on the DataDomain systems. Replication may get stuck with lower-end DataDomains, especially when undersized and with constant high load. While the issue is acknowledged and a fix may be in the way, parallelism in this case should be avoided, as doing backup and DD replication sequentially works properly.