Matt,
I respectfully disagree; there is indeed an easy answer.
First, the term "reliable" is ambiguous and must be clarified before
engaging in a meaningful discussion. In this discussion, I believe the
term "reliable" is not defined as the "absence of failure", but instead
as "loss-less transmission of data", with "loss-less" meaning "complete
and accurate".
TCP and UDP are alternative protocols residing at layer 4 (transport) of
the 7-layer OSI model <https://en.wikipedia.org/wiki/OSI_model>. The
first three layers of the OSI model define the hardware carrier,
structure, framing, addressing, and routing of data, and it is at the
transport layer that the branch between loss-less and loss-y session
protocols is implemented.
NFS is implemented at level 7 (application) of the model, and so the
question of "reliability" (as I believe we are discussing it) has been
resolved several layers down.
In any context (analog, digital, or human), "reliable" never means
"perfect". Error, loss, and corruption is always possible for a myriad
of reasons, applying equally to any protocol. TCP is "loss-less" by
design, but no design is absolutely perfect.
Hope this helps!
-Tim
On 6/3/16 13:17, Matt wrote:
I do not think there is an easy answer whether or not nfs mounts are reliable. IT depends upon your organization infrastructe teams. I have worked at organizations were my nfs mounts were completely unreliable. My current organization I cannot remember the last time I have had an issue with my nfs mounts.
Thanks, Matt
*From:*oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] *On Behalf Of *Robert Freeman
*Sent:* Friday, June 3, 2016 1:31 PM
*To:* Michael Cunningham
*Cc:* oracle-l@freelists org
*Subject:* RE: Is nfs reliable?
I would not have an issue with monitoring scripts… However, anything diagnostic or the like I’d keep on local storage…
*From:*Michael Cunningham [mailto:napacunningham@xxxxxxxxx]
*Sent:* Friday, June 03, 2016 11:30 AM
*To:* Robert Freeman <rfreeman@xxxxxxxxxxxxxxxxx <mailto:rfreeman@xxxxxxxxxxxxxxxxx>>
*Cc:* oracle-l@freelists org <oracle-l@xxxxxxxxxxxxx <mailto:oracle-l@xxxxxxxxxxxxx>>
*Subject:* Re: Is nfs reliable?
Robert, how would you feel about having a library of monitoring scripts on an nfs mount? I do this so that scripts are available on every Oracle server. I also backup config files, etc. to this mount making it easy for me to scan, in a single directory, something like all cron backup files to see where something is running. It's these things why I feel the nfs mount serves a great benefit. And many others...
Michael
On Fri, Jun 3, 2016 at 8:34 AM, Robert Freeman <rfreeman@xxxxxxxxxxxxxxxxx <mailto:rfreeman@xxxxxxxxxxxxxxxxx>> wrote:
Mike,
We Run our RAC databases using NFS as the shared media for
datafiles. We have yet to have a failure because of NFS. We don’t
use shared software directories however, just local directories.
My personal preference is for local software.
RF
*From:*oracle-l-bounce@xxxxxxxxxxxxx
<mailto:oracle-l-bounce@xxxxxxxxxxxxx>
[mailto:oracle-l-bounce@xxxxxxxxxxxxx
<mailto:oracle-l-bounce@xxxxxxxxxxxxx>] *On Behalf Of *Michael
Cunningham
*Sent:* Friday, June 03, 2016 12:02 AM
*To:* oracle-l@freelists org <oracle-l@xxxxxxxxxxxxx
<mailto:oracle-l@xxxxxxxxxxxxx>>
*Subject:* Is nfs reliable?
I had someone tell me today that nfs should not be relied on and
it should not be used for a shared mount that needed to be
reliably available.
Has anyone ever hear this before?
--
Michael Cunningham
--
Michael Cunningham