Configuring TSM server on LAN, SAN and NAS networks


Tivoli Storage Manager provides various methods for configuring storage devices. TSM Storage devices can be configured on a Local Area Network (LAN), on a Storage Area Network (SAN) for LAN-free data movement  and on Network-Attached Storage (NAS). 

TSM Storage Devices on Local Area Networks (LAN)

In the conventional local area network (LAN) configuration, one or more tape or optical libraries are associated with a single Tivoli Storage Manager server. In a LAN configuration, client data, electronic mail, terminal connection, application program, and device control information must all be handled by the same network. Device control information and client backup and restore data flow across the LAN. Some Tape Libraries cannot be partitioned or shared in a LAN environment.

TSM Storage Devices on Storage Area Networks (SAN)

A SAN is a dedicated storage network that can improve system performance. On a SAN you can consolidate storage and relieve the distance, scalability, and bandwidth limitations of LANs and wide area networks (WANs). Using Tivoli Storage Manager in a SAN allows the following functions.
  • Sharing storage devices among multiple Tivoli Storage Manager servers. 
  • Allowing Tivoli Storage Manager clients, through a storage agent on the client machine, to move data directly to storage devices (LAN-free data movement).
In a SAN you can share tape drives, optical drives, and libraries that are supported by the Tivoli Storage Manager server, including most SCSI devices.

Also Read: Storage Area Network (SAN) Basic Free Tutorials

When two  or more Tivoli Storage Manager servers share a library, one of the TSM servers which is referred as the Library Manager controls device operations. These operations include mount, dismount, volume ownership, and library inventory. Other Tivoli Storage Manager servers, which acts as a Library Clients, use server-to-server communications to contact the library manager and request device service. Data moves over the SAN between each server and the storage device.

TSM LAN-Free Data Movement Procedure

Tivoli Storage Manager allows a client, through a storage agent, to directly back up and restore data to a tape library on a SAN. LAN-free data movement requires the installation of a storage agent software on the client machine. TSM Server maintains the database and recovery log, and acts as the library manager to control device operations. The storage agent on the client handles the data transfer to the device on the SAN. This implementation frees up bandwidth on the LAN that would otherwise be used for client data movement.

Also Read: Installation & Configuration of TSM Storage Agent (Lanfree Backup)

The following outlines a typical backup scenario for a client that uses LAN-free data movement

  • The client begins a backup operation. The client and the server exchange policy information over the LAN to determine the destination of the backed up data. For a client using LAN-free data movement, the destination is a storage pool that uses a device on the SAN.
  • Because the destination is on the SAN, the client contacts the storage agent, which will handle the data transfer. The storage agent sends a request for a volume mount to the server.
  • The server contacts the storage device and, in the case of a tape library, mounts the appropriate media.
  • The server notifies the client of the location of the mounted media.
  • The client, through the storage agent, writes the backup data directly to the device over the SAN.
  • The storage agent sends file attribute information to the server, and the server stores the information in its database.
If a failure occurs on the SAN path, failover occurs. The client uses its LAN connection to the Tivoli Storage Manager server and moves the client data over the LAN.

TSM Storage Devices on Network-Attached Storage (NAS)

Network-attached storage (NAS) file servers are dedicated storage machines whose operating systems are optimized for file-serving functions. NAS file servers typically do not run software 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. 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 on-site disaster.
  • 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. 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 all the backend-data management features associated with a conventional Tivoli Storage Manager storage-pool hierarchy, including migration and reclamation.
Also Read: Different types of libraries supported by IBM Spectrum Protect (TSM)

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

TSM NDMP Backup Procedure
In backup images produced by network data management protocol (NDMP) operations for a NAS file server, Tivoli Storage Manager creates NAS file-system-level or directory-level image backups. The image backups are different from traditional Tivoli Storage Manager backups because the NAS file server transfers the data to the drives in the library or directly to the Tivoli Storage Manager server. NAS file system image backups can be either full or differential image backups. The first backup of a file system on a NAS file server is always a full image backup. By default, subsequent backups are differential image backups containing only data that has changed in the file system since the last full image backup. If a full image backup does not already exist, a full image backup is performed.

If you restore a differential image, Tivoli Storage Manager automatically restores the full backup image first, followed by the differential image.

NDMP file-level Restoration
Tivoli Storage Manager provides a way to restore data from backup images produced by NDMP operations. To assist users in restoring selected files, you can create a table of contents (TOC) of file-level information for each backup image. Using the Web backup-archive client, users can then browse the TOC and select the files that they want to restore. If you do not create a TOC, users must be able to specify the name of the backup image that contains the file to be restored and the fully qualified name of the file.

You can create a TOC using one of the following commands:
  • BACKUP NODE server command. 
  • BACKUP NAS client command, with include.fs.nas specified in the client options file or specified in the client options set. 
Directory-level Backup and Restore
If you have a large NAS file system, initiating a backup on a directory level reduces backup and restore times, and provides more flexibility in configuring your NAS backups. By defining virtual file spaces, a file system backup can be partitioned among several NDMP backup operations and multiple tape drives. You can also use different backup schedules to back up sub-trees of a file system.

The virtual file space name cannot be identical to any file system on the NAS node. If a file system is created on the NAS device with the same name as a virtual file system, a name conflict will occur on the Tivoli Storage Manager server when the new file space is backed up. 




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