[Ocfs2-users] PBL with RMAN and ocfs2

[Sunil Mushran]

http://www.netapp.com/tech_library/ftp/3183.pdf
<<<<<<<<
When running applications such as databases that depend on end-to-end 
data integrity, you should use
“hard,nointr.” Oracle has verified that using intr instead of nointr can 
expose your database to the risk
of corruption when a database instance is signaled (for example, during 
a “shutdown abort” sequence).
 >>>>>>>>

Alexei Roudnev wrote:
> 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
>>>>
>>>>
>>>>         
>>>       
>>     
>
>
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