Network-attached storage

Network-attached storage (NAS) file servers are dedicated storage servers whose operating systems are optimized for file-serving functions. NAS file servers typically do not run software that is acquired from another vendor. Instead, they interact with programs like Tivoli® Storage Manager through industry-standard network protocols, such as network data management protocol (NDMP).

Tivoli Storage Manager provides two basic types of configurations that use NDMP for backing up and managing NAS file servers. In one type of configuration, Tivoli Storage Manager uses NDMP to back up a NAS file server to a library device directly attached to the NAS file server. (See Figure 1.) The NAS file server, which can be distant from the Tivoli Storage Manager server, transfers backup data directly to a drive in a SCSI-attached tape library. Data is stored in special, NDMP-formatted storage pools, which can be backed up to storage media that can be moved offsite for protection in case of an onsite disaster.

Figure 1. Library device directly attached to a NAS file server

A Tivoli Storage Manager server communicates with a NAS file server over a TCP/IP connection. The NAS file server sends data to NAS file system disks and to a tape library over SCSI or Fibre Channel connections. Storage volumes in the tape library can be moved offsite.

In the other type of NDMP-based configuration, Tivoli Storage Manager uses NDMP to back up a NAS file server to a Tivoli Storage Manager storage-pool hierarchy. (See Figure 2.) With this type of configuration, you can store NAS data directly to disk (either random access or sequential access) and then migrate the data to tape. Data can also be backed up to storage media that can then be moved offsite. The advantage of this type of configuration is that it gives you all the backend-data management features associated with a conventional Tivoli Storage Manager storage-pool hierarchy, including migration and reclamation.

Figure 2. NAS file server toTivoli Storage Manager storage-pool hierarchy

A Tivoli Storage Manager server communicates with a NAS file server over a TCP/IP connection. The NAS file server sends data to the Tivoli Storage Manager server, which provides disk, tape library, and offsite storage options.

In both types of configurations, Tivoli Storage Manager tracks file system image backups and has the capability to perform NDMP file-level restores. For more information about NDMP file-level restores, see NDMP file-level restoration.

Note:

A CENTERA storage device cannot be a target for NDMP operations.
Support for filer-to-server data transfer is only available for NAS devices that support NDMP version 4.
For a comparison of NAS backup methods, including the use of a backup-archive client to back up a NAS file server, see Determining the location of NAS backup.