Administrator Guide

Figure 49. Two-Way Conguration
NOTE: If a controller loses the connectivity to the tape, the NDMP session assigned to the controller will fail.
Conguring and Adjusting NDMP Two-Way Backup
Tape Connectivity
You must dene the zoning so that the FC-attached tape drive can be seen by the HBAs on all NAS controllers. Drives must be
available through every HBA port so that you can choose which port to use for each backup, and balance the load between HBA
ports.
NOTE: The Linux multipathing driver does not support character devices; tape devices cannot be multipathed. You must
choose a specic SCSI device, which uses a specic HBA port for each backup job.
Adding a Tape Device
1. Click the Storage view and select a FluidFS cluster.
2. Click the File System tab.
3. In the File System view, click Cluster Connectivity.
4. Click the Backup tab and scroll down to Tape Devices.
5. Click Create Tape Devices.
The Create Tape Devices dialog box opens.
6. Select an ID from Physical ID and type a name for the tape device in the Name eld. Rescan if required.
7. Click OK.
Handling Hard Links
NDMP backup handles hard link les in the most ecient way by default. That is, the hard link les’ data content will be backed up
only once. After the backup operation encounters the rst hard link le and backs up its content, the backup process remembers the
inode number of that le. Subsequently, when the backup operation encounters les with the same inode number, only the header is
backed up. When this backup data stream is restored, the hard link les will be recovered as hard link les.
This mode of backup could create a problem in the case of a selective restore when the selected les or directories to be restored
contain hard link les that are not the rst instance encountered during backup. In this case, the restore fails and an NDMP message
is sent to the DMA server indicating the rst instance of the le that should also be included in the selective restore.
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FluidFS Data Protection