NDMP is an acronym for Network Data Management Protocol, which is an open standard protocol for enterprise-wide backups of heterogeneous network-attached storage. NDMP is an Internet-Draft standard that uses port 10000 by default.
For more details on NDMP Protocol please see the following site:
http://www.ndmp.org.
Architectural Model:
The architecture follows a client-server model and the backup software is considered to be a client to the NDMP server. For every connection between the client and the NDMP host, there is a virtual state machine on the NDMP host that is controlled using NDMP. This virtual state machine is referred to as the NDMP server.
Architectural Model:
The architecture follows a client-server model and the backup software is considered to be a client to the NDMP server. For every connection between the client and the NDMP host, there is a virtual state machine on the NDMP host that is controlled using NDMP. This virtual state machine is referred to as the NDMP server.
Currently an NDMP server can be thought of providing two services:
A DATA server - This service either reads from disk and produces an NDMP data stream (in a specified format) or reads an NDMP data stream and writes to disk, depending upon whether a backup or restore is taking place.
A TAPE server - This service either reads an NDMP data stream and writes it to tape or reads from tape and writes an NDMP data stream, depending upon whether a backup or restore is taking place. All tape-handling functions, such as split-image issues, are dealt with by this service.
NDMP Filers (NAS):
DMP Filers, or NAS devices, reside on the network with the primary purpose of providing file services. NAS devices that use standard operating systems (for example, Windows-powered NAS devices) support the installation of backup agents, and can therefore be backed up like any other file server. However, some NAS devices use a custom operating system that does not support third party backup agents. A standard backup interface for NAS devices exists in the form of the network data management protocol (NDMP), which is a backup standard for NAS devices that do not support installation of a backup agent.
NDMP - Direct Attached:(Shown above in Figure)
In the direct-attached or local model, the backup server uses NDMP over the LAN to instruct the filer to start the backup. The filer then sends the data contained in the backup to a tape device attached directly to the filer via Fibre Channel or SCSI. During the backup, information about files and directories written to tape is transferred via NDMP over the LAN to the backup server where it is maintained in an index. For a restore operation, the backup server uses NDMP over the LAN to instruct the filer to start restoring files. Data is read from the filer's locally attached tape device and stored by the filer. During backup and restore, the backup server does not ever receive the actual data being written or read from tape. As a result, this model is commonly referred to as "LAN-free" backup.
NDMP - Filer to Filer (3-way): (Shown above in Figure)
In the filer-to-filer model, often referred to as three-way, the backup server uses NDMP over the LAN to instruct filer A to start backing up data to tape devices attached to filer B via either the same network or a private backup network. During the backup, information about files and directories written to tape is transferred from filer A via NDMP over the LAN to the backup server, where it is maintained in an index.
This is known as 3-way backup, since typically 3 hosts are involved.
The host running the NDMP client (1).
The host running the NDMP DATA server (2).
The host running the NDMP TAPE server (3).
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