CentOS is a "clone" of RHEL, built from RHEL source code -- with some
modifications to remove Redhat Trademarks.
For most purposes, you can be confident that CentOS will behave (almost)
identically to RHEL of the same release, however, you will encounter some
differences:
- Third-party device drivers distributed for RHEL in binary format may
not work on CentOS. (Worse, I suppose -- they could appear to work, and
later malfunction.)
- Kernel modifications provided by Oracle will probably not work.
- You will encounter minor issues with installation -- although, as Don
Seiler points out, these are easy to overcome.
I have used CentOS in my sandboxes for years, and been perfectly happy with
it. I have used CentOS in production too, without serious mishaps, but
never at my own recommendation. (That is, the customer insisted, and I was
powerless to stop them.)
CentOS will *probably* be "okay" on a database server where you don't need
fancy-schmancy behavour out of the kernel, but definitely think twice if
you are going to start playing with features that might start interacting
with the OS at a lower level -- features like RAC, or ASM, or third-party
IO multipathing, or...
Here is possibly the greatest thing to consider when choosing between
CentOS or Redhat or Oracle Enterprise Linux:
*What exactly do you hope to gain by running a "cheaper" operating system?*
The answer to that question is usually "obvious" -- you hope to save
money. But do you? Really?
Consider a "small" server running Oracle Enterprise Edition, with a few
common options like Partitioning, Diagnostics Pack, and Tuning Pack. This
"small" server, with (for illustration purposes) two 12-core processors
will have 12 "CPUs" for the purposes of Oracle licensing calculations.
Oracle EE + Partitioning + Diagnostics + Tuning has a *list price* of
roughly $70,000 per CPU. For this "small" server, that will be a list
price of $840,000 for the database software, plus about $180,000 per year
for support.
How much does RHEL cost? I have not priced RHEL or OEL recently, but as I
recall, they cost *nothing* -- you only pay for support. But that support
is only a few thousand dollars per year. (With OEL being a little cheaper
than RHEL.)
Let's assume its about $5,000 per server per year for support -- that's
about 3% of the cost of the support for the database software. You are
definitely going to assume some risk in replacing RHEL or OEL with CentOS
-- is that risk really worthwhile for a 3% savings?
Of course, if you redo this analysis with Oracle Standard Edition (or
Standard Edition ONE), the numbers are *very* different. A financial case
might be made for using a "free" Linux distro with Oracle Standard Edition
ONE.
On Sun, May 24, 2015 at 2:34 PM, Diego Cutrone <cutroned@xxxxxxxxx> wrote:
Hi David, agree with Ron. Oracle works on CENTOS, I currently have
Oracle 11g RDBMS and GI running in a Centos 6.5 – but for testing purposes
only. I don’t think this is supported/certified by Oracle at all..
HTH
Diego
*From:* oracle-l-bounce@xxxxxxxxxxxxx [mailto:
oracle-l-bounce@xxxxxxxxxxxxx] *On Behalf Of *Don Seiler
*Sent:* Sunday, May 24, 2015 3:06 PM
*To:* David Ramírez Reyes
*Cc:* utahtoad@xxxxxxxxx; ORACLE-L
*Subject:* Re: RHEL to CentOS
Yeah it's easy to spoof a CentOS server to look like RHEL or OEL to the
OUI. The problem is when you need help from Oracle Support on a prod
database. You don't want to give them any reason to not help you because
you didn't follow their rules.
On Sun, May 24, 2015 at 12:28 PM, David Ramírez Reyes <dramirezr@xxxxxxxxx>
wrote:
Just from the Oracle installation, you will receive a message saying that
the Linux distro is not supported by Oracle and then the Oracle SW can't be
installed; that's one of the first checks that Oracle specifies on the
Installation documentation, check that your OS is supported for Oracle DB.
Am sure there are tricks to force it, but you have no warranty on that.
Good luck!
On Sunday, 24 May 2015, Don Seiler <don@xxxxxxxxx> wrote:
The bigger concern would be that CentOS is not supported by Oracle (as far
as I know). If they created an SR and Oracle support found out they were on
centos then they could balk on providing any help.
On May 24, 2015 11:16 AM, "David Hicken" <utahtoad@xxxxxxxxx> wrote:
One of my client's SysAdmins wants to move their Oracle 11.2.0.1 DB from
RHEL 5 to a version of CentOS (5?). I have never done his kind of thing. I
googled but couldn't find anything definitive.
I'm wondering if the database files, etc. can be moved and brought up
under the new CentOS, or if I have to move it through RMAN or the like. Is
it an in place upgrade? Will the binaries need re-installed or re-linked?
This is new to me.
Does anyone have some pointers/ articles / MOS posts/ support pages to
which they can direct me?
Thanks, all.
David Hicken
Utahtoad@xxxxxxxxx
"There is no reality.
It's only perception."
--
David Ramírez Reyes
Profesión: Padre de Familia
--
Don Seiler
http://www.seiler.us
