Data Protector NDMP Integration Quickstart Guide

3
NAS concept
Network-attached storage (NAS) is file-level computer data storage connected to a computer network
providing data access to heterogeneous network clients.
Although it may technically be possible to run other software on a NAS unit, it is not designed to be a
general purpose server. For example, NAS units usually do not have a keyboard or display, and are
controlled and configured over the network, often using a browser.
A fully-featured operating system is not needed on a NAS device, so often a stripped-down or
customized standard operating system is used, such as Linux.
NAS systems contain one or more hard disks, often arranged into logical, redundant storage
containers or RAID arrays (redundant arrays of inexpensive/independent disks) often referred to
primary storage.
NAS removes the responsibility of file serving from other servers on the network.
NAS uses file-based protocols such as NFS (popular on UNIX systems), SMB/CIFS (Server Message
Block/Common Internet File System) (used with MS Windows systems), AFP (used with Apple
Macintosh computers), WebDAV, HTTP/HTTPS and FTP/FTPS to serve data to applications or users.
NAS units rarely limit clients to a single protocol.
You can now back up data residing on a filer to what is often called secondary storage in two
different ways:
 On the Application Server
 Direct from the filer to tape using NDMP
The first method would be a “normal” backup, using the Data Protector Disk Agent, which is installed
on each Application Server. During backup, data is transferred via the LAN to the system to which a
tape device is connected.
The second way uses the NDMP integration of Data Protector and performs the backup locally on the
NDMP server. This has two major advantages:
 The backup data does not need to be transferred over the LAN.
 There is no performance degradation on the Application Server.
NAS NDMP 2-way or local backup concept
The NDMP architecture uses a client-server model in which Data Protector is the NDMP client (DMA-
Data Management Application) to the NDMP-Host Data Mover (NDMP server or DSP-Data Service
Provider).
During an NDMP backup, backup data flows from the primary storage system to the Data Mover, and
then on to the secondary storage system, such as an attached tape library backup device, without
traversing the Ethernet network. Only the backup software‟s control data, catalog data, and tape
library commands are send over the network, using NDMP protocol.
In a 2-way or local backup scenario (Figure 1) both primary and secondary storage are directly
attached to the filer using either SCSI or Fiber Channel connections.
The Data Mover maintains a state machine for each NDMP client connection that executes and
maintains backup and restore processes.
Note: Please refer to the filer vendor documentation to find the supported NDMP session concurrency
scheme. Up to version 6.2, Data Protector only supports the 2-way or local backup concept.