Quantum DXi4510, User Manual

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Chapter 6: DXi4000 Replication
Understanding Data Replication
82 Quantum DXi4000 User’s Guide
Understanding Data Replication
During data replication, data is sent from one system (the source) to
another system, usually in another location (the target). For example,
you might replicate data from a branch office (the source) to a central
office (the target).
Sources
send
replicated data, and targets
receive
replicated data. A
target system can receive data from up to 10 sources. However, a source
system can send data to only a single target. Finally, one system can act
as both a source and a target.
Replication works only with deduplicated data, and data is compressed
before it is replicated. Because of this, the amount of data transmitted
between systems during replication is greatly reduced compared to the
original amount of data stored. In addition, a data block is transmitted
only if the target does not already have a copy of the block. Finally, data
can optionally be encrypted before it is transmitted.
The DXi4000 can perform the following types of replication:
• Replication
• Directory/File Based Replication
• OST Optimized Duplication
Replication
Replication occurs when replication is enabled for a deduplicated NAS
share and a replication schedule is configured (or manual replication is
performed on a regular basis). For replication to occur, the source
system must be configured to point to the target system. Similarly, the
target system must be configured to accept data from the source
system.
To optimize the replication process, deduplicated data is continuously
sent in the background from the source system to the target system.
However, a snapshot that preserves the file structure of your data is sent
to the target system only when a scheduled or manual replication job
occurs. A snapshot contains all of the information that is necessary to
recreate a share just as it was at the point in time when the snapshot
was created.