VERITAS NetBackup, Белая книга

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w w w . v e r i t a s . c o m P a g e 23 V E R I T A S N e t B a c k u p R e l e a s e 3 . 4 Te c h n i c a l O v e r v i e w
Checkpoint/Restart of Backup Sessions
NetBackup’s multistreaming capability enables failed streams of a multistreamed backup to be restarted in the event of a
backup failure. Once service is resumed, the backup will restart the failed stream rather than restarting the entire backup job.
Checkpoints may be set at file system mount points or at file and/or directory paths as defined in the NetBackup class “file
list” (see the “NetBackup Classes” section above). Additional checkpoint options will be supported in future releases.
From a restore perspective, each checkpoint creates a complete and standalone NetBackup image on tape that can be used
for restore regardless of whether or not the rest of the backup session is completed.
Checkpoint/restart is not supported for restores at this time. In addition, checkpoint/restart is not supported for manual
backups or user initiated backups.
Compressing Backup Data
VERITAS NetBackup is capable of compressing data as part of the backup operation. The compression and decompression
takes place on the client and its effectiveness depends on the type of data being compressed. In the right circumstances,
compression can significantly reduce both storage requirements and network traffic. In general, most customers find the
hardware compression provided by tape devices a much simpler and efficient method of compression.
Backing Up Network (CIFS / NFS) Files
VERITAS NetBackup optionally backs up files that are resident on a PC network file server or NFS file server mounted on a
VERITAS NetBackup client. This is useful for backing up remote files or an unsupported client platform that has files NFS
mounted on some other VERITAS NetBackup client system (Figure 18).
Normally, it is undesirable for a client backup operation to include such files because the data transfer goes through the
network protocol (IPX, TCP/IP, or NFS). It is better to back up the data on the platform where the files physically reside,
making backup through NFS /CIFS unnecessary.
Figure 18: Using NFS mounts to back up unsupported clients.