VERITAS NetBackup White Paper page 14

FlashBackup uses snapshot technology to provide high performance, online "file image" backups of mounted file systems
while still allowing restores of individual files and directories. FlashBackup significantly enhances backup performance for file
servers, web servers, and internet mail servers that have file systems that contain a large number of small files. High
performance backups are accomplished with minimal overhead on the host system being backed up. FlashBackup delivers
the performance of raw file system backup without losing the flexibility of restores at the individual file and/or directory level.
Both full and incremental FlashBackup backups are supported and are performed with a single sweep of the source disk,
eliminating unnecessary head movement. All restores are performed with a single pass of the media, which optimizes restore
times.
Figure 7 illustrates the FlashBackup backup process. FlashBackup delivers the high performance of a raw partition backup
(i.e. it bypasses the buffered I/O of the file system) and dramatically reduces CPU utilization during the backup process. A
disk "snapshot" capability provides a consistent view of the live disk during backup
the disk, even though users may continue to change the contents of the disk during the backup operation.
FlashBackup can dramatically enhance backup performance – especially in environments with large numbers of small files.
Backup performance improvements of 6x -10x are commonplace in NFS file server, web server, and pop mail server
environments. For example, Figure 8 graphs backup times for a customer with a large number of files on their file system
that reduced their backup window from 72 hours using a standard backup to 11 hours using the FlashBackup option.
1
Supported file systems include Solaris running UFS or the VERITAS File System, HP-UX running Online JFS or the VERITAS File System
Auspex. Support for other platforms is planned for future releases.
2
When FlashBackup is used with VERITAS File System, the online snapshot capability of VERITAS File System is used. When FlashBackup is
used with Solaris UFS or HP-UX Online JFS, FlashBackup provides the online snapshot capability.
P a g e 12 V E R I TA 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
Figure 7: NetBackup FlashBackup
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