Which two statements are true about the Oracle Direct Network File system (DNFS)?
A.
It utilizes the OS file system cache.
B.
A traditional NFS mount is not required when using Direct NFS.
C.
Oracle Disk Manager can manage NFS on its own, without using the operating kernel NFS driver.
D.
Direct NFS is available only in UNIX platforms.
E.
Direct NFS can load-balance I/O traffic across multiple network adapters.
Explanation:
E: Performance is improved by load balancing across multiple network interfaces (if available).
Note:
* To enable Direct NFS Client, you must replace the standard Oracle Disk Manager (ODM) library with one
that supports Direct NFS Client.
Incorrect:
Not A: Direct NFS Client is capable of performing concurrent direct I/O, which bypasses any operating
system level caches and eliminates any operating system write-ordering locks
Not B:
* To use Direct NFS Client, the NFS file systems must first be mounted and available over regular NFS
mounts.
* Oracle Direct NFS (dNFS) is an optimized NFS (Network File System) client that provides faster and more
scalable access to NFS storage located on NAS storage devices (accessible over TCP/IP).
Not D: Direct NFS is provided as part of the database kernel, and is thus available on all supported
database platforms – even those that don’t support NFS natively, like Windows.
Note:
* Oracle Direct NFS (dNFS) is an optimized NFS (Network File System) client that provides faster and more
scalable access to NFS storage located on NAS storage devices (accessible over TCP/IP). Direct NFS is
built directly into the database kernel – just like ASM which is mainly used when using DAS or SAN storage.
* Oracle Direct NFS (dNFS) is an internal I/O layer that provides faster access to large NFS files than
traditional NFS clients.