[Ocfs2-users] PBL with RMAN and ocfs2

[Alexei Roudnev]

Oracle requires it BY MISTAKE and in documentation only (but not in the
system). It works better with 'intr' mode on NFS.

nointr prevents SHUTDOWN to kill application. As a result, if NFS server
died you can't kill application (such as rman for example).

I personally advice AGAINST 'nointr' in any environment esp. for the things
other then redo logs. The best setting for NFS should be

  tcp,hard,intr,noac (rsize and wsize optional, and not 'bg')

PS. Oracle dont require 'nointr' in reality; it require (verifies) 'hard'
mount but 'nointr' is optional. 'hard' prevents io interruptions because of
network glitches and so is required for consistency, while having 'intr'
option allows shutdown to work correctly and do not have any danger (no
difference IO is sticked AND someone shutdown appllication).  Allowing
'nointr' mounts in production 100% guarantee problems with shutdowns. And
btw, any non-network mount behaves as 'soft' and not 'hard' so it is even
more amazing who selected these options in oracle (soft could be even better
choice because it translate IO errors to the application
so appolication can make a preventive actions). I already had a fun because
of this strange requirements for 'hard' (we dont want 'hard' mount for
backup area),
but I can live with 'hard' if 'intr' is turned on (but not without it).

PPS. What's the use of preventing interrupted IO-s? if someone can't
shutdown your application because 'nointr' then he
will power reset the whole server (so making things much worst because
application can't shutdown normally). With 'intr', yes application got io
error in io and signal in high level and will die (or shutdown depending of
signal) and it is better then power reset the whole box.

Do you want application (oracle archiver for example) to be sticked forever
if one of NFS servers (one of a few archive destinations) don't answer? I
dont think so,


----- Original Message ----- 
From: "Sunil Mushran" <Sunil.Mushran at oracle.com>
To: "Alexei_Roudnev" <Alexei_Roudnev at exigengroup.com>
Cc: "Dheerendar Srivastav" <Dheerendars at bajajcapital.com>;
<Ocfs2-users at oss.oracle.com>
Sent: Monday, May 14, 2007 11:29 AM
Subject: Re: [Ocfs2-users] PBL with RMAN and ocfs2


> nointr blocks signals during the io itself. Prevents short ios.
> AFAIK, Oracle requires a similar mount option with NFS too.
>
> Alexei_Roudnev wrote:
> > Btw, why Oracle like nointr?  Our analyze shows that 'intr' can be used
> > instead in all cases andf is much safer. (at least for the NFS)
> >
> >  For NFS., intr means that mount is hard (application never got IO
failure
> > but just try IO forever - it's discussional too but we can agree with
this
> > approach)
> > BUT if can be killed or interrupted. So that if IO is frozen and other
> > application sends shutdown signal (such as kill -9) then application
will be
> > killed.
> > Without intr, if your NFS server died, you wil not be able to shutdown
your
> > server without power reset (or reboot -n -f in some cases).
> >
> >
> > ----- Original Message ----- 
> > From: "Sunil Mushran" <Sunil.Mushran at oracle.com>
> > To: "Dheerendar Srivastav" <Dheerendars at bajajcapital.com>
> > Cc: <Ocfs2-users at oss.oracle.com>
> > Sent: Monday, May 14, 2007 9:43 AM
> > Subject: Re: [Ocfs2-users] PBL with RMAN and ocfs2
> >
> >
> >
> >> Ensure you have mounted the volume storing the
> >> ocr and the voting diskfile with the "nointr,datavolume"
> >> mount options.
> >>
> >>
http://oss.oracle.com/projects/ocfs2/dist/documentation/ocfs2_faq.html#RAC
> >>
> >> Dheerendar Srivastav wrote:
> >>
> >>> Dear sir ,
> >>>
> >>> We have used RHEL 4.0 with kernel 2.6.9-42.0.2.ELsmp with ocfs2 , we
> >>> have oracle 10g 10.1.0.2
> >>>
> >>> I am working on a RAC installation (10.1.0.2)on RHEL 4.0 with EMC
> >>> caliriion shared storage . The EMC device have been linked to raw
> >>> devices .
> >>>
> >>> We are able to configure ocfs2 and
> >>> ASM . When we will installed CRS the error message show " oracle
> >>> cluster Registery can exists only as a shared file system file or as a
> >>> shared raw partion .
> >>>
> >>> I would like request how to install the OCRFile .
> >>>
> >>>
> >> _______________________________________________
> >> Ocfs2-users mailing list
> >> Ocfs2-users at oss.oracle.com
> >> http://oss.oracle.com/mailman/listinfo/ocfs2-users
> >>
> >>
> >
> >
>
>