It looks like we are
running into an oracle bug and this is not related to the o_direct flag.
Im not installing it
myself, this is done by a oracle expert, and I don’t have the exact error
code yet….hopefully tomorrow.
But they found a bug regarding
rac installation on emc which shows similar problems during rac installation.
So it looks like this is
an oracle/rhel issue…
Anyway, thanks for your
explanation about o_direct ;-)
alex
Von: Matthew
Zito [mailto:mzito@gridapp.com]
Gesendet: Montag, 05. November
2007 17:08
An: Alexander Schalek;
toasters@mathworks.com
Betreff: RE: accessing lun as a
raw device using dm-multipathing from a rhel host
If you're in RHEL4, you just point your
voting, OCR, etc. at the relevant /dev/mapper/mpath0, etc. device, and Oracle
uses the O_DIRECT flag when it opens the device. What is the error you're
getting?
Matt
--Matthew ZitoChief ScientistGridApp SystemsP: 646-452-4090mzito@gridapp.comhttp://www.gridapp.comFrom:
owner-toasters@mathworks.com on behalf of Alexander Schalek
Sent: Mon 11/5/2007 10:02 AM
To: toasters@mathworks.com
Subject: accessing lun as a raw
device using dm-multipathing from a rhel host
Hi!
I have some troubles with a oracle rac installation
on netapp fcp luns.
We use rhel4 u5 with dm-multipathing with a 2.6
kernel
Currently we have 4 partitioned and multipathed luns
maped to the hosts(mpath0-3) but the rac installation exits with an error.
I found the following lines in the fcp host utilities
setup guide:
Accessing
LUNs using dm-multipath
Accessing LUNs as a raw
devices
Overview
Instead of creating a file
system, you can access a LUN as a raw device.
Be sure to use the /dev/mapper/
device created by dm-multipath to access the raw
device.
For the Linux
2.6 kernel used by RHEL 4, do not use the raw interface. Instead
open the
device using the open call with the O_DIRECT flag.
*****
So I have to access the devices using the open call
with the O_DIRECT flag!?
Can anyone of you guys explain this sentence to me?
How do I do that?
Many thanks and best regards,
Alexander