Users are eager to test Oracle Corp.'s embedded network file system
(NFS) client that will allow data from its
version 11g database to bypass underlying operating systems
when it runs on
network attached storage (NAS).
Oracle said the client, developed with Network Appliance Inc.
(NetApp), will boost performance and simplify management of
databases attached to NAS.
The Direct NFS (DNFS) client is a free new feature of 11g. DNFS
pulls the NFS client, normally a component of the operating system
that sits on top of Ethernet drivers, into Oracle's database
software. The idea is to let NFS communicate automatically with
storage systems. In the past, users have had to manually tune every
individual operating system's NFS parameters, including block size,
cache size or conditions for forcing direct-block I/O to disk.
Users in large NetApp/Oracle shops said that they haven't yet
tested the feature, but the concept seems to solve a longstanding
problem in managing storage for Oracle databases. "You mean I
wouldn't have to tell my Unix admin how to manage his server every
time I install storage?" said a storage administrator from a major
financial services firm who asked that neither he nor his company
be named. "If it works, that'll make my storage team's life a lot
easier."
"It's huge," said a senior manager of data services for a
Midwestern application services provider (ASP) who also asked that
he and his company remain unidentified. "We constantly worry about
any OS upgrade because bugs might cause data corruption on our
filers -- this would eliminate that variable."
NetApp claims that the client will address a longstanding issue
with Oracle databases attached to NAS systems -- performance. Data
will have one less hop between Oracle software and the back-end
storage device. NetApp senior director of enterprise alliances and
solutions Phil Brotherton said this could have a big impact on
older versions of common operating systems, such as Solaris. "On a
perfectly tuned, brand-new system, the performance bump will be
around 10%," he said. "But for users running older, less optimized
versions of operating systems like Solaris 8, the jump could be up
to 50%."
Databases have traditionally run on block-level storage systems
because of performance. Especially before the turn of the
millennium, the ability to manually tune exactly how a database
laid out bits on each sector of disk was key to providing adequate
storage performance for high-volume transactional applications. In
the most performance-sensitive environments, this is still the case
today.
However, the performance of file-based NAS has increased,
closing the gap between NAS and block-level storage area network
(SAN) systems. Meanwhile, allowing the file system layer of a NAS
system to determine the layout of bits on disk makes it easier to
manage and appeals to less performance-intensive shops.
"Before, the difference between NAS and SAN storage for
databases was the difference between disaster and acceptability,"
said analyst Arun Taneja of the Taneja Group. "Now, there's
generally no more than a 10% performance difference."
That doesn't mean DNFS will push companies to move their
databases to NAS en masse -- DBAs still worry about performance
problems, they said.
Another hurdle to adoption is that it's part of Oracle's newest
version, which has only been shipping since August. "I wish we were
a year into 11g already so I could use this feature," said the data
services manager from the Midwestern ASP. "We never update our
database before the second release of the software."
Even once that happens, he added, his company will be slow and
careful about introducing a new element into its databases. "If you
introduce something new into the environment, it's great if it's
really an improvement," he said. "But if it doesn't work and causes
data corruption, it can be a career-limiting move."
Oracle has also been promoting the use of grids, commodity
servers that can be glued together using its Real Application
Clusters (RAC) and Automatic Storage Management (ASM) software and
moved between storage systems and physical clusters at will. Both
Oracle and NetApp say that DNFS will provide a standardized
NFSinterface for those server nodes, making it easier to drop them
into place quickly.