An improvement has been done for POSIX versions to address a problem whereby
the full backup tool of the nBackup incremental backup utility
would hog I/O resources when backing up large databases, bringing production work
to a standstill. Now, nBackup tries to read from the operating system cache before
attempting to read from disk, thus reducing the I/O load substantially.
Note
The “cost” may be a 10 to 15 percent increase in the time taken
to complete the full backup under high-load conditions.
Tracker reference CORE-2316.