Administrator Guide

Managing NDMP
The FluidFS cluster supports Network Data Management Protocol (NDMP), which is an open standard protocol that facilitates
backup operations for network attached storage, including
FluidFS cluster NAS volumes. NDMP should be used for longer-term data
protection, such as weekly backups with long retention periods.
The FluidFS cluster supports remote and three-way backup architecture implementations, wherein a supported, external Data
Management Application (DMA) server mediates the data transfer between the FluidFS cluster and the storage device. The FluidFS
cluster supports full, dierential, and incremental NDMP Level Based Backup (levels 0-9), Full, Incremental/Dierential Token Based
Backup, and Direct Access Recovery (DAR). The FluidFS cluster supports NDMP versions 2, 3, and 4 (default mode).
The FluidFS cluster includes an NDMP server that is responsible for the following operations:
• Processing all NDMP backup and restore requests sent from DMA servers
• Sending all NDMP replies and notication messages to DMA servers
• Transferring data over the network to or from remote NDMP tape or data servers
The NDMP server handles all communications with the DMA servers and other NDMP devices through an XDR encoded TCP
(Transmission Control Protocol) data stream.
The NDMP server supports two backup types:
• dump: Generates inode-based NDMP le history
• tar: Generates path-based NDMP le history
The backup type is controlled by the NDMP environment variable TYPE. Both backup types support the same functionalities, but
the tar backup type might be able to process the information more eciently for certain DMA servers.
Incremental Backups
Each time a backup is performed, the NDMP server stores the timestamp for the backup. When the NDMP server performs an
incremental backup, it uses the timestamp stored for the previous full or incremental backup to determine if a directory or le needs
to be included.
Both supported backup types (dump and tar) support incremental backup. The algorithm for traversing the backup target directory
is the same. However, because inode-based le history generation has dierent requirements to support DAR, the backup data
stream generated is dierent:
• dump: Each directory visited will be backed up and a le history entry will be generated. It does not matter whether the directory
has changed.
• tar: Backs up and generates a le history entry only for the directories that have changed.
Therefore, the amount of data backed up using a tar backup will be less than that of a dump backup. The size dierence depends on
the number of directories in the backup data set.
NDMP Two-Way Backup
FluidFS supports two-way NDMP congurations where the tape device is directly attached to the data host, either physically or
through a fast internal network. The data service and the tape service both reside on the same NDMP server, and the data
connection is internal to the NDMP server. Both data and tape control commands are communicated through one control
connection from the DMA to the NDMP server..
NOTE: iSCSI solutions do not support the direct attach NDMP feature.
FluidFS Data Protection
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