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* [Ocfs2-devel] Please help me in getting OCFS2 design doc.
@ 2006-04-27 14:50 Sum Sha
  2006-04-27 17:03 ` Sunil Mushran
  0 siblings, 1 reply; 8+ messages in thread
From: Sum Sha @ 2006-04-27 14:50 UTC (permalink / raw)
  To: ocfs2-devel

Hi all,
Could someone point me to design doc for OCFS2? I could get OCFS V-1
design doc, but could not find any design doc for OCFS2. I read
somewhere that OCFS2 has got lots of design changes as comapared to
OCFS1.

Thanks in advance.

^ permalink raw reply	[flat|nested] 8+ messages in thread
* [Ocfs2-devel] Please help me in getting OCFS2 design doc.
  2006-04-27 14:50 Sum Sha
@ 2006-04-27 17:03 ` Sunil Mushran
  0 siblings, 0 replies; 8+ messages in thread
From: Sunil Mushran @ 2006-04-27 17:03 UTC (permalink / raw)
  To: ocfs2-devel

Look into docs in ocfs2 projects page. While there
is no design doc, there is a presentation which lists
out the changes.

http://oss.oracle.com/projects/ocfs2/documentation/

Sum Sha wrote:
> Hi all,
> Could someone point me to design doc for OCFS2? I could get OCFS V-1
> design doc, but could not find any design doc for OCFS2. I read
> somewhere that OCFS2 has got lots of design changes as comapared to
> OCFS1.
>
> Thanks in advance.
>
> _______________________________________________
> Ocfs2-devel mailing list
> Ocfs2-devel at oss.oracle.com
> http://oss.oracle.com/mailman/listinfo/ocfs2-devel
>   

^ permalink raw reply	[flat|nested] 8+ messages in thread
* [Ocfs2-devel] Please help me in getting OCFS2 design doc.
@ 2006-05-02 14:15 Sum Sha
  2006-05-02 17:11 ` Sunil Mushran
  0 siblings, 1 reply; 8+ messages in thread
From: Sum Sha @ 2006-05-02 14:15 UTC (permalink / raw)
  To: ocfs2-devel

Thanks Sunil for this information. I tried going through the docs mentioned
there, they are useful, but there are details which I wanted for my
learning purpose which are not in those docs. It would be great if anyone
can share any good doc mentioning details about Clustering Services which
OCFS2 uses. I know that clustering services which OCFS2 uses has the
following components:

1. Node manager
2. Heartbeat module
3. TCP Protocol module
4. DLM

But once I install and configure OCFS2, I can see the following modules
getting loaded:

1. configfs (with filesystem mounted)
2. ocfs2_nodemanger
3. ocfs2_dlm
4. ocfs2_dlmfs (with filesystem mounted)

and the following threads created:
1. ocfs2_wq (perhaps it's the kernel worker thread)
2. ocfs2_vote (for voting requests. Is this the listener thread?)
3. ocfs2_cmt (perhaps this is the node monitoring thread?)

Can't think of OCFS2 in 10g environment where we have another required and
reliable clustering service CRS (with 10g) running and managing Oracle's
resources. Do CRS and OCFS's clustering services co-ordinate in some manner
or do they take actions independently on their own during crash and other
conditions?

Any help would be highly appreciated!!

Thanks.
Sumsha.

On 4/28/06, ocfs2-devel-request at oss.oracle.com <
ocfs2-devel-request@oss.oracle.com> wrote:
>
> Send Ocfs2-devel mailing list submissions to
>         ocfs2-devel at oss.oracle.com
>
> To subscribe or unsubscribe via the World Wide Web, visit
>         http://oss.oracle.com/mailman/listinfo/ocfs2-devel
> or, via email, send a message with subject or body 'help' to
>         ocfs2-devel-request at oss.oracle.com
>
> You can reach the person managing the list at
>         ocfs2-devel-owner at oss.oracle.com
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of Ocfs2-devel digest..."
>
>
> Today's Topics:
>
>    1. Re: Please help me in getting OCFS2 design doc. (Sunil Mushran)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Thu, 27 Apr 2006 10:03:23 -0700
> From: Sunil Mushran <Sunil.Mushran@oracle.com>
> Subject: Re: [Ocfs2-devel] Please help me in getting OCFS2 design doc.
> To: Sum Sha <sumsha.matrixreloaded@gmail.com>
> Cc: ocfs2-devel at oss.oracle.com
> Message-ID: <4450F95B.8000704@oracle.com>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Look into docs in ocfs2 projects page. While there
> is no design doc, there is a presentation which lists
> out the changes.
>
> http://oss.oracle.com/projects/ocfs2/documentation/
>
> Sum Sha wrote:
> > Hi all,
> > Could someone point me to design doc for OCFS2? I could get OCFS V-1
> > design doc, but could not find any design doc for OCFS2. I read
> > somewhere that OCFS2 has got lots of design changes as comapared to
> > OCFS1.
> >
> > Thanks in advance.
> >
> > _______________________________________________
> > Ocfs2-devel mailing list
> > Ocfs2-devel at oss.oracle.com
> > http://oss.oracle.com/mailman/listinfo/ocfs2-devel
> >
>
>
>
> ------------------------------
>
> _______________________________________________
> Ocfs2-devel mailing list
> Ocfs2-devel at oss.oracle.com
> http://oss.oracle.com/mailman/listinfo/ocfs2-devel
>
>
> End of Ocfs2-devel Digest, Vol 25, Issue 10
> *******************************************
>
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^ permalink raw reply	[flat|nested] 8+ messages in thread
* [Ocfs2-devel] Please help me in getting OCFS2 design doc.
  2006-05-02 14:15 [Ocfs2-devel] Please help me in getting OCFS2 design doc Sum Sha
@ 2006-05-02 17:11 ` Sunil Mushran
  2006-05-03 11:18   ` Sum Sha
  0 siblings, 1 reply; 8+ messages in thread
From: Sunil Mushran @ 2006-05-02 17:11 UTC (permalink / raw)
  To: ocfs2-devel

The modules don't map one on one. The idea is to keep the
number of modules at a minimum while retaining some sense
modularity.

For e.g., ocfs2_nodemanager.ko  encompasses nm, heartbeat and net/tcp.

The various kernel/worker threads may change over time.
For e.g., we added dlm_wq in the last drop. Again, the idea is to
keep the threads at a minimum while still functioning. :)

o2cb (ocfs2 cluster stack) and crs have nothing in common. No, they
don't talk to each other. o2cb is almost entirely implemented in kernel
space while crs in userspace.

ocfs2 default timings are much shorter than crs. The idea is to recover
dead nodes before crs times out.

Sum Sha wrote:
> Thanks Sunil for this information. I tried going through the docs 
> mentioned there, they are useful, but there are details which I wanted 
> for my  learning purpose which are not in those docs. It would be 
> great if anyone can share any good doc mentioning details about 
> Clustering Services which OCFS2 uses. I know that clustering services 
> which OCFS2 uses has the following components:
>
> 1. Node manager
> 2. Heartbeat module
> 3. TCP Protocol module
> 4. DLM
>
> But once I install and configure OCFS2, I can see the following 
> modules getting loaded:
>
> 1. configfs (with filesystem mounted)
> 2. ocfs2_nodemanger
> 3. ocfs2_dlm
> 4. ocfs2_dlmfs (with filesystem mounted)
>
> and the following threads created:
> 1. ocfs2_wq (perhaps it's the kernel worker thread)
> 2. ocfs2_vote (for voting requests. Is this the listener thread?)
> 3. ocfs2_cmt (perhaps this is the node monitoring thread?)
>
> Can't think of OCFS2 in 10g environment where we have another required 
> and reliable clustering service CRS (with 10g) running and managing 
> Oracle's resources. Do CRS and OCFS's clustering services co-ordinate 
> in some manner or do they take actions independently on their own 
> during crash and other conditions?
>
> Any help would be highly appreciated!!
>
> Thanks.
> Sumsha.
>
> On 4/28/06, *ocfs2-devel-request at oss.oracle.com 
> <mailto:ocfs2-devel-request@oss.oracle.com>* < 
> ocfs2-devel-request at oss.oracle.com 
> <mailto:ocfs2-devel-request@oss.oracle.com>> wrote:
>
>     Send Ocfs2-devel mailing list submissions to
>             ocfs2-devel at oss.oracle.com <mailto:ocfs2-devel@oss.oracle.com>
>
>     To subscribe or unsubscribe via the World Wide Web, visit
>              http://oss.oracle.com/mailman/listinfo/ocfs2-devel
>     or, via email, send a message with subject or body 'help' to
>             ocfs2-devel-request at oss.oracle.com
>     <mailto:ocfs2-devel-request@oss.oracle.com>
>
>     You can reach the person managing the list at
>             ocfs2-devel-owner at oss.oracle.com
>     <mailto:ocfs2-devel-owner@oss.oracle.com>
>
>     When replying, please edit your Subject line so it is more specific
>     than "Re: Contents of Ocfs2-devel digest..."
>
>
>     Today's Topics:
>
>        1. Re: Please help me in getting OCFS2 design doc. (Sunil Mushran)
>
>
>     ----------------------------------------------------------------------
>
>
>     Message: 1
>     Date: Thu, 27 Apr 2006 10:03:23 -0700
>     From: Sunil Mushran <Sunil.Mushran@oracle.com
>     <mailto:Sunil.Mushran@oracle.com>>
>     Subject: Re: [Ocfs2-devel] Please help me in getting OCFS2 design
>     doc.
>     To: Sum Sha <sumsha.matrixreloaded@gmail.com
>     <mailto:sumsha.matrixreloaded@gmail.com>>
>     Cc: ocfs2-devel at oss.oracle.com <mailto:ocfs2-devel@oss.oracle.com>
>     Message-ID: < 4450F95B.8000704@oracle.com
>     <mailto:4450F95B.8000704@oracle.com>>
>     Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
>     Look into docs in ocfs2 projects page. While there
>     is no design doc, there is a presentation which lists
>     out the changes.
>
>     http://oss.oracle.com/projects/ocfs2/documentation/
>
>     Sum Sha wrote:
>     > Hi all,
>     > Could someone point me to design doc for OCFS2? I could get OCFS
>     V-1
>     > design doc, but could not find any design doc for OCFS2. I read
>     > somewhere that OCFS2 has got lots of design changes as comapared to
>     > OCFS1.
>     >
>     > Thanks in advance.
>     >
>     > _______________________________________________
>     > Ocfs2-devel mailing list
>     > Ocfs2-devel at oss.oracle.com <mailto:Ocfs2-devel@oss.oracle.com>
>     > http://oss.oracle.com/mailman/listinfo/ocfs2-devel
>     <http://oss.oracle.com/mailman/listinfo/ocfs2-devel>
>     >
>
>
>
>     ------------------------------
>
>     _______________________________________________
>     Ocfs2-devel mailing list
>     Ocfs2-devel at oss.oracle.com <mailto:Ocfs2-devel@oss.oracle.com>
>     http://oss.oracle.com/mailman/listinfo/ocfs2-devel
>
>
>     End of Ocfs2-devel Digest, Vol 25, Issue 10
>     *******************************************
>
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> Ocfs2-devel mailing list
> Ocfs2-devel at oss.oracle.com
> http://oss.oracle.com/mailman/listinfo/ocfs2-devel
>   

^ permalink raw reply	[flat|nested] 8+ messages in thread
* [Ocfs2-devel] Please help me in getting OCFS2 design doc.
  2006-05-02 17:11 ` Sunil Mushran
@ 2006-05-03 11:18   ` Sum Sha
  2006-05-03 23:51     ` Sunil Mushran
  0 siblings, 1 reply; 8+ messages in thread
From: Sum Sha @ 2006-05-03 11:18 UTC (permalink / raw)
  To: ocfs2-devel

Thanks a bunch for the reply, which could give me some inside view without
going through the code. It'd have been great, if you had written a doc
mentioning all these details and rolled it out :)

There are some ocfs2_wq, ocfs2_vote and ocfs2_cmt threads created, when I
mount a shared volume. Any details about them?

Moreover, as you said that OCFS2 has shorter timings than that of CRS, so do
we solely depend on this fact (shorter timings) to prevent CRS from
intruding into racing during crash and split-brain situations. I was just
trying to understand how it works. I think CRS misscount is 60 for Linux. Do
we believe that by this time, OCFS2 would have taken all the decisions and
completed the recovery before CRS (or rather CSSD) starts its ejection
mechanism? Without ASM, how do we ensure that underlying Volume Manager's
recovery has been completed before OCFS2 starts its recovery. And how does
it happen when we use ASM?

Sorry, if I am going out of the context, but just wanted to get some
information how they co-ordinate.

Thanks.
Sumsha.
On 5/2/06, Sunil Mushran <Sunil.Mushran@oracle.com> wrote:
>
> The modules don't map one on one. The idea is to keep the
> number of modules at a minimum while retaining some sense
> modularity.
>
> For e.g., ocfs2_nodemanager.ko  encompasses nm, heartbeat and net/tcp.
>
> The various kernel/worker threads may change over time.
> For e.g., we added dlm_wq in the last drop. Again, the idea is to
> keep the threads at a minimum while still functioning. :)
>
> o2cb (ocfs2 cluster stack) and crs have nothing in common. No, they
> don't talk to each other. o2cb is almost entirely implemented in kernel
> space while crs in userspace.
>
> ocfs2 default timings are much shorter than crs. The idea is to recover
> dead nodes before crs times out.
>
> Sum Sha wrote:
> > Thanks Sunil for this information. I tried going through the docs
> > mentioned there, they are useful, but there are details which I wanted
> > for my  learning purpose which are not in those docs. It would be
> > great if anyone can share any good doc mentioning details about
> > Clustering Services which OCFS2 uses. I know that clustering services
> > which OCFS2 uses has the following components:
> >
> > 1. Node manager
> > 2. Heartbeat module
> > 3. TCP Protocol module
> > 4. DLM
> >
> > But once I install and configure OCFS2, I can see the following
> > modules getting loaded:
> >
> > 1. configfs (with filesystem mounted)
> > 2. ocfs2_nodemanger
> > 3. ocfs2_dlm
> > 4. ocfs2_dlmfs (with filesystem mounted)
> >
> > and the following threads created:
> > 1. ocfs2_wq (perhaps it's the kernel worker thread)
> > 2. ocfs2_vote (for voting requests. Is this the listener thread?)
> > 3. ocfs2_cmt (perhaps this is the node monitoring thread?)
> >
> > Can't think of OCFS2 in 10g environment where we have another required
> > and reliable clustering service CRS (with 10g) running and managing
> > Oracle's resources. Do CRS and OCFS's clustering services co-ordinate
> > in some manner or do they take actions independently on their own
> > during crash and other conditions?
> >
> > Any help would be highly appreciated!!
> >
> > Thanks.
> > Sumsha.
> >
> > On 4/28/06, *ocfs2-devel-request at oss.oracle.com
> > <mailto:ocfs2-devel-request@oss.oracle.com>* <
> > ocfs2-devel-request at oss.oracle.com
> > <mailto:ocfs2-devel-request@oss.oracle.com>> wrote:
> >
> >     Send Ocfs2-devel mailing list submissions to
> >             ocfs2-devel at oss.oracle.com <mailto:
> ocfs2-devel at oss.oracle.com>
> >
> >     To subscribe or unsubscribe via the World Wide Web, visit
> >              http://oss.oracle.com/mailman/listinfo/ocfs2-devel
> >     or, via email, send a message with subject or body 'help' to
> >             ocfs2-devel-request at oss.oracle.com
> >     <mailto:ocfs2-devel-request@oss.oracle.com>
> >
> >     You can reach the person managing the list at
> >             ocfs2-devel-owner at oss.oracle.com
> >     <mailto:ocfs2-devel-owner@oss.oracle.com>
> >
> >     When replying, please edit your Subject line so it is more specific
> >     than "Re: Contents of Ocfs2-devel digest..."
> >
> >
> >     Today's Topics:
> >
> >        1. Re: Please help me in getting OCFS2 design doc. (Sunil
> Mushran)
> >
> >
> >
> ----------------------------------------------------------------------
> >
> >
> >     Message: 1
> >     Date: Thu, 27 Apr 2006 10:03:23 -0700
> >     From: Sunil Mushran <Sunil.Mushran@oracle.com
> >     <mailto:Sunil.Mushran@oracle.com>>
> >     Subject: Re: [Ocfs2-devel] Please help me in getting OCFS2 design
> >     doc.
> >     To: Sum Sha <sumsha.matrixreloaded@gmail.com
> >     <mailto:sumsha.matrixreloaded@gmail.com>>
> >     Cc: ocfs2-devel at oss.oracle.com <mailto:ocfs2-devel@oss.oracle.com>
> >     Message-ID: < 4450F95B.8000704@oracle.com
> >     <mailto:4450F95B.8000704@oracle.com>>
> >     Content-Type: text/plain; charset=ISO-8859-1; format=flowed
> >
> >     Look into docs in ocfs2 projects page. While there
> >     is no design doc, there is a presentation which lists
> >     out the changes.
> >
> >     http://oss.oracle.com/projects/ocfs2/documentation/
> >
> >     Sum Sha wrote:
> >     > Hi all,
> >     > Could someone point me to design doc for OCFS2? I could get OCFS
> >     V-1
> >     > design doc, but could not find any design doc for OCFS2. I read
> >     > somewhere that OCFS2 has got lots of design changes as comapared
> to
> >     > OCFS1.
> >     >
> >     > Thanks in advance.
> >     >
> >     > _______________________________________________
> >     > Ocfs2-devel mailing list
> >     > Ocfs2-devel at oss.oracle.com <mailto:Ocfs2-devel@oss.oracle.com>
> >     > http://oss.oracle.com/mailman/listinfo/ocfs2-devel
> >     <http://oss.oracle.com/mailman/listinfo/ocfs2-devel>
> >     >
> >
> >
> >
> >     ------------------------------
> >
> >     _______________________________________________
> >     Ocfs2-devel mailing list
> >     Ocfs2-devel at oss.oracle.com <mailto:Ocfs2-devel@oss.oracle.com>
> >     http://oss.oracle.com/mailman/listinfo/ocfs2-devel
> >
> >
> >     End of Ocfs2-devel Digest, Vol 25, Issue 10
> >     *******************************************
> >
> >
> > ------------------------------------------------------------------------
> >
> > _______________________________________________
> > Ocfs2-devel mailing list
> > Ocfs2-devel at oss.oracle.com
> > http://oss.oracle.com/mailman/listinfo/ocfs2-devel
> >
>
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^ permalink raw reply	[flat|nested] 8+ messages in thread
* [Ocfs2-devel] Please help me in getting OCFS2 design doc.
  2006-05-03 11:18   ` Sum Sha
@ 2006-05-03 23:51     ` Sunil Mushran
  2006-05-08 13:23       ` Sum Sha
  0 siblings, 1 reply; 8+ messages in thread
From: Sunil Mushran @ 2006-05-03 23:51 UTC (permalink / raw)
  To: ocfs2-devel

The faq has been updated with descriptions of the various threads.

ASM and OCFS2 have nothing in common. Volumes can either
be OCFS2 or part of an ASM disk group but not both.

Sum Sha wrote:
> Thanks a bunch for the reply, which could give me some inside view 
> without going through the code. It'd have been great, if you had 
> written a doc mentioning all these details and rolled it out :)
>
> There are some ocfs2_wq, ocfs2_vote and ocfs2_cmt threads created, 
> when I mount a shared volume. Any details about them?
>
> Moreover, as you said that OCFS2 has shorter timings than that of CRS, 
> so do we solely depend on this fact (shorter timings) to prevent CRS 
> from intruding into racing during crash and split-brain situations. I 
> was just trying to understand how it works. I think CRS misscount is 
> 60 for Linux. Do we believe that by this time, OCFS2 would have taken 
> all the decisions and completed the recovery before CRS (or rather 
> CSSD) starts its ejection mechanism? Without ASM, how do we ensure 
> that underlying Volume Manager's recovery has been completed before 
> OCFS2 starts its recovery. And how does it happen when we use ASM?
>
> Sorry, if I am going out of the context, but just wanted to get some 
> information how they co-ordinate.
>
> Thanks.
> Sumsha.
> On 5/2/06, *Sunil Mushran* <Sunil.Mushran@oracle.com 
> <mailto:Sunil.Mushran@oracle.com>> wrote:
>
>     The modules don't map one on one. The idea is to keep the
>     number of modules at a minimum while retaining some sense
>     modularity.
>
>     For e.g., ocfs2_nodemanager.ko  encompasses nm, heartbeat and net/tcp.
>
>     The various kernel/worker threads may change over time.
>     For e.g., we added dlm_wq in the last drop. Again, the idea is to
>     keep the threads at a minimum while still functioning. :)
>
>     o2cb (ocfs2 cluster stack) and crs have nothing in common. No, they
>     don't talk to each other. o2cb is almost entirely implemented in
>     kernel
>     space while crs in userspace.
>
>     ocfs2 default timings are much shorter than crs. The idea is to
>     recover
>     dead nodes before crs times out.
>
>     Sum Sha wrote:
>     > Thanks Sunil for this information. I tried going through the docs
>     > mentioned there, they are useful, but there are details which I
>     wanted
>     > for my  learning purpose which are not in those docs. It would be
>     > great if anyone can share any good doc mentioning details about
>     > Clustering Services which OCFS2 uses. I know that clustering
>     services
>     > which OCFS2 uses has the following components:
>     >
>     > 1. Node manager
>     > 2. Heartbeat module
>     > 3. TCP Protocol module
>     > 4. DLM
>     >
>     > But once I install and configure OCFS2, I can see the following
>     > modules getting loaded:
>     >
>     > 1. configfs (with filesystem mounted)
>     > 2. ocfs2_nodemanger
>     > 3. ocfs2_dlm
>     > 4. ocfs2_dlmfs (with filesystem mounted)
>     >
>     > and the following threads created:
>     > 1. ocfs2_wq (perhaps it's the kernel worker thread)
>     > 2. ocfs2_vote (for voting requests. Is this the listener thread?)
>     > 3. ocfs2_cmt (perhaps this is the node monitoring thread?)
>     >
>     > Can't think of OCFS2 in 10g environment where we have another
>     required
>     > and reliable clustering service CRS (with 10g) running and managing
>     > Oracle's resources. Do CRS and OCFS's clustering services
>     co-ordinate
>     > in some manner or do they take actions independently on their own
>     > during crash and other conditions?
>     >
>     > Any help would be highly appreciated!!
>     >
>     > Thanks.
>     > Sumsha.
>     >
>     > On 4/28/06, *ocfs2-devel-request at oss.oracle.com
>     <mailto:ocfs2-devel-request@oss.oracle.com>
>     > <mailto: ocfs2-devel-request@oss.oracle.com
>     <mailto:ocfs2-devel-request@oss.oracle.com>>* <
>     > ocfs2-devel-request at oss.oracle.com
>     <mailto:ocfs2-devel-request@oss.oracle.com>
>     > <mailto:ocfs2-devel-request@oss.oracle.com
>     <mailto:ocfs2-devel-request@oss.oracle.com>>> wrote:
>     >
>     >     Send Ocfs2-devel mailing list submissions to
>     >             ocfs2-devel at oss.oracle.com
>     <mailto:ocfs2-devel@oss.oracle.com>
>     <mailto:ocfs2-devel@oss.oracle.com
>     <mailto:ocfs2-devel@oss.oracle.com>>
>     >
>     >     To subscribe or unsubscribe via the World Wide Web, visit
>     >              http://oss.oracle.com/mailman/listinfo/ocfs2-devel
>     >     or, via email, send a message with subject or body 'help' to
>     >             ocfs2-devel-request at oss.oracle.com
>     <mailto:ocfs2-devel-request@oss.oracle.com>
>     >     <mailto:ocfs2-devel-request@oss.oracle.com
>     <mailto:ocfs2-devel-request@oss.oracle.com>>
>     >
>     >     You can reach the person managing the list at
>     >             ocfs2-devel-owner at oss.oracle.com
>     <mailto:ocfs2-devel-owner@oss.oracle.com>
>     >     <mailto:ocfs2-devel-owner@oss.oracle.com
>     <mailto:ocfs2-devel-owner@oss.oracle.com>>
>     >
>     >     When replying, please edit your Subject line so it is more
>     specific
>     >     than "Re: Contents of Ocfs2-devel digest..."
>     >
>     >
>     >     Today's Topics:
>     >
>     >        1. Re: Please help me in getting OCFS2 design doc. (Sunil
>     Mushran)
>     >
>     >
>     >    
>     ----------------------------------------------------------------------
>     >
>     >
>     >     Message: 1
>     >     Date: Thu, 27 Apr 2006 10:03:23 -0700
>     >     From: Sunil Mushran < Sunil.Mushran@oracle.com
>     <mailto:Sunil.Mushran@oracle.com>
>     >     <mailto:Sunil.Mushran@oracle.com
>     <mailto:Sunil.Mushran@oracle.com>>>
>     >     Subject: Re: [Ocfs2-devel] Please help me in getting OCFS2
>     design
>     >     doc.
>     >     To: Sum Sha <sumsha.matrixreloaded@gmail.com
>     <mailto:sumsha.matrixreloaded@gmail.com>
>     >     <mailto:sumsha.matrixreloaded@gmail.com
>     <mailto:sumsha.matrixreloaded@gmail.com>>>
>     >     Cc: ocfs2-devel at oss.oracle.com
>     <mailto:ocfs2-devel@oss.oracle.com>
>     <mailto:ocfs2-devel@oss.oracle.com
>     <mailto:ocfs2-devel@oss.oracle.com>>
>     >     Message-ID: < 4450F95B.8000704@oracle.com
>     <mailto:4450F95B.8000704@oracle.com>
>     >     <mailto:4450F95B.8000704@oracle.com
>     <mailto:4450F95B.8000704@oracle.com>>>
>     >     Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>     >
>     >     Look into docs in ocfs2 projects page. While there
>     >     is no design doc, there is a presentation which lists
>     >     out the changes.
>     >
>     >     http://oss.oracle.com/projects/ocfs2/documentation/
>     >
>     >     Sum Sha wrote:
>     >     > Hi all,
>     >     > Could someone point me to design doc for OCFS2? I could
>     get OCFS
>     >     V-1
>     >     > design doc, but could not find any design doc for OCFS2. I
>     read
>     >     > somewhere that OCFS2 has got lots of design changes as
>     comapared to
>     >     > OCFS1.
>     >     >
>     >     > Thanks in advance.
>     >     >
>     >     > _______________________________________________
>     >     > Ocfs2-devel mailing list
>     >     > Ocfs2-devel at oss.oracle.com
>     <mailto:Ocfs2-devel@oss.oracle.com>
>     <mailto:Ocfs2-devel@oss.oracle.com
>     <mailto:Ocfs2-devel@oss.oracle.com>>
>     >     > http://oss.oracle.com/mailman/listinfo/ocfs2-devel
>     >     <http://oss.oracle.com/mailman/listinfo/ocfs2-devel
>     <http://oss.oracle.com/mailman/listinfo/ocfs2-devel>>
>     >     >
>     >
>     >
>     >
>     >     ------------------------------
>     >
>     >     _______________________________________________
>     >     Ocfs2-devel mailing list
>     >     Ocfs2-devel at oss.oracle.com
>     <mailto:Ocfs2-devel@oss.oracle.com>
>     <mailto:Ocfs2-devel@oss.oracle.com
>     <mailto:Ocfs2-devel@oss.oracle.com>>
>     >     http://oss.oracle.com/mailman/listinfo/ocfs2-devel
>     <http://oss.oracle.com/mailman/listinfo/ocfs2-devel>
>     >
>     >
>     >     End of Ocfs2-devel Digest, Vol 25, Issue 10
>     >     *******************************************
>     >
>     >
>     >
>     ------------------------------------------------------------------------
>
>     >
>     > _______________________________________________
>     > Ocfs2-devel mailing list
>     > Ocfs2-devel at oss.oracle.com <mailto:Ocfs2-devel@oss.oracle.com>
>     > http://oss.oracle.com/mailman/listinfo/ocfs2-devel
>     >
>
>

^ permalink raw reply	[flat|nested] 8+ messages in thread
* [Ocfs2-devel] Please help me in getting OCFS2 design doc.
  2006-05-03 23:51     ` Sunil Mushran
@ 2006-05-08 13:23       ` Sum Sha
  2006-05-08 17:50         ` Sunil Mushran
  0 siblings, 1 reply; 8+ messages in thread
From: Sum Sha @ 2006-05-08 13:23 UTC (permalink / raw)
  To: ocfs2-devel

Thanks again for providing this information. I thought, we create
volumes with ASM and then format those volumes with OCFS2 and then
mount them. I probably missed it ;-)

One more thing which I'd be interested to discuss is "heartbeat
mechanism" and "self-fencing" behaviour of OCFS2.

I have read that
"An active node is deemed dead if it does not update its timestamp for
O2CB_HEARTBEAT_THRESHOLD (default=7) loops"
                                          and
"A node self-fences if it fails to update its timestamp for
((O2CB_HEARTBEAT_THRESHOLD - 1) * 2) secs. The [o2hb-xx] kernel
thread, after every timestamp write, sets a timer to panic the system
after that duration. If the next timestamp is written within that
duration, as it should, it first cancels that timer before setting up
a new one"

Here, the first case seems to be dependent on the second one, isn't
it? If a node is not able to see other nodes' timestamp within
(O2CB_HEARTBEAT_THRESHOLD * 2) time, then it assumes one of the
following things:

1. The other node could not put timestamp within
(O2CB_HEARTBEAT_THRESHOLD - 1) * 2 time and paniced itself.
                               OR
2. The other node is actually dead and we give extra 2 seconds to
detect that. Are we giving these extra 2 seconds to [hb-xx] kernel
thread for detecting this scenario?

Is this true?

Thanks in advance.
Sumsha.

On 5/4/06, Sunil Mushran <Sunil.Mushran@oracle.com> wrote:
> The faq has been updated with descriptions of the various threads.
>
> ASM and OCFS2 have nothing in common. Volumes can either
> be OCFS2 or part of an ASM disk group but not both.
>
> Sum Sha wrote:
> > Thanks a bunch for the reply, which could give me some inside view
> > without going through the code. It'd have been great, if you had
> > written a doc mentioning all these details and rolled it out :)
> >
> > There are some ocfs2_wq, ocfs2_vote and ocfs2_cmt threads created,
> > when I mount a shared volume. Any details about them?
> >
> > Moreover, as you said that OCFS2 has shorter timings than that of CRS,
> > so do we solely depend on this fact (shorter timings) to prevent CRS
> > from intruding into racing during crash and split-brain situations. I
> > was just trying to understand how it works. I think CRS misscount is
> > 60 for Linux. Do we believe that by this time, OCFS2 would have taken
> > all the decisions and completed the recovery before CRS (or rather
> > CSSD) starts its ejection mechanism? Without ASM, how do we ensure
> > that underlying Volume Manager's recovery has been completed before
> > OCFS2 starts its recovery. And how does it happen when we use ASM?
> >
> > Sorry, if I am going out of the context, but just wanted to get some
> > information how they co-ordinate.
> >
> > Thanks.
> > Sumsha.
> > On 5/2/06, *Sunil Mushran* <Sunil.Mushran@oracle.com
> > <mailto:Sunil.Mushran@oracle.com>> wrote:
> >
> >     The modules don't map one on one. The idea is to keep the
> >     number of modules at a minimum while retaining some sense
> >     modularity.
> >
> >     For e.g., ocfs2_nodemanager.ko  encompasses nm, heartbeat and net/tcp.
> >
> >     The various kernel/worker threads may change over time.
> >     For e.g., we added dlm_wq in the last drop. Again, the idea is to
> >     keep the threads at a minimum while still functioning. :)
> >
> >     o2cb (ocfs2 cluster stack) and crs have nothing in common. No, they
> >     don't talk to each other. o2cb is almost entirely implemented in
> >     kernel
> >     space while crs in userspace.
> >
> >     ocfs2 default timings are much shorter than crs. The idea is to
> >     recover
> >     dead nodes before crs times out.
> >
> >     Sum Sha wrote:
> >     > Thanks Sunil for this information. I tried going through the docs
> >     > mentioned there, they are useful, but there are details which I
> >     wanted
> >     > for my  learning purpose which are not in those docs. It would be
> >     > great if anyone can share any good doc mentioning details about
> >     > Clustering Services which OCFS2 uses. I know that clustering
> >     services
> >     > which OCFS2 uses has the following components:
> >     >
> >     > 1. Node manager
> >     > 2. Heartbeat module
> >     > 3. TCP Protocol module
> >     > 4. DLM
> >     >
> >     > But once I install and configure OCFS2, I can see the following
> >     > modules getting loaded:
> >     >
> >     > 1. configfs (with filesystem mounted)
> >     > 2. ocfs2_nodemanger
> >     > 3. ocfs2_dlm
> >     > 4. ocfs2_dlmfs (with filesystem mounted)
> >     >
> >     > and the following threads created:
> >     > 1. ocfs2_wq (perhaps it's the kernel worker thread)
> >     > 2. ocfs2_vote (for voting requests. Is this the listener thread?)
> >     > 3. ocfs2_cmt (perhaps this is the node monitoring thread?)
> >     >
> >     > Can't think of OCFS2 in 10g environment where we have another
> >     required
> >     > and reliable clustering service CRS (with 10g) running and managing
> >     > Oracle's resources. Do CRS and OCFS's clustering services
> >     co-ordinate
> >     > in some manner or do they take actions independently on their own
> >     > during crash and other conditions?
> >     >
> >     > Any help would be highly appreciated!!
> >     >
> >     > Thanks.
> >     > Sumsha.
> >     >
> >     > On 4/28/06, *ocfs2-devel-request at oss.oracle.com
> >     <mailto:ocfs2-devel-request@oss.oracle.com>
> >     > <mailto: ocfs2-devel-request@oss.oracle.com
> >     <mailto:ocfs2-devel-request@oss.oracle.com>>* <
> >     > ocfs2-devel-request at oss.oracle.com
> >     <mailto:ocfs2-devel-request@oss.oracle.com>
> >     > <mailto:ocfs2-devel-request@oss.oracle.com
> >     <mailto:ocfs2-devel-request@oss.oracle.com>>> wrote:
> >     >
> >     >     Send Ocfs2-devel mailing list submissions to
> >     >             ocfs2-devel at oss.oracle.com
> >     <mailto:ocfs2-devel@oss.oracle.com>
> >     <mailto:ocfs2-devel@oss.oracle.com
> >     <mailto:ocfs2-devel@oss.oracle.com>>
> >     >
> >     >     To subscribe or unsubscribe via the World Wide Web, visit
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> >     >     or, via email, send a message with subject or body 'help' to
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> >     >     You can reach the person managing the list at
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> >     >     <mailto:ocfs2-devel-owner@oss.oracle.com
> >     <mailto:ocfs2-devel-owner@oss.oracle.com>>
> >     >
> >     >     When replying, please edit your Subject line so it is more
> >     specific
> >     >     than "Re: Contents of Ocfs2-devel digest..."
> >     >
> >     >
> >     >     Today's Topics:
> >     >
> >     >        1. Re: Please help me in getting OCFS2 design doc. (Sunil
> >     Mushran)
> >     >
> >     >
> >     >
> >     ----------------------------------------------------------------------
> >     >
> >     >
> >     >     Message: 1
> >     >     Date: Thu, 27 Apr 2006 10:03:23 -0700
> >     >     From: Sunil Mushran < Sunil.Mushran@oracle.com
> >     <mailto:Sunil.Mushran@oracle.com>
> >     >     <mailto:Sunil.Mushran@oracle.com
> >     <mailto:Sunil.Mushran@oracle.com>>>
> >     >     Subject: Re: [Ocfs2-devel] Please help me in getting OCFS2
> >     design
> >     >     doc.
> >     >     To: Sum Sha <sumsha.matrixreloaded@gmail.com
> >     <mailto:sumsha.matrixreloaded@gmail.com>
> >     >     <mailto:sumsha.matrixreloaded@gmail.com
> >     <mailto:sumsha.matrixreloaded@gmail.com>>>
> >     >     Cc: ocfs2-devel at oss.oracle.com
> >     <mailto:ocfs2-devel@oss.oracle.com>
> >     <mailto:ocfs2-devel@oss.oracle.com
> >     <mailto:ocfs2-devel@oss.oracle.com>>
> >     >     Message-ID: < 4450F95B.8000704@oracle.com
> >     <mailto:4450F95B.8000704@oracle.com>
> >     >     <mailto:4450F95B.8000704@oracle.com
> >     <mailto:4450F95B.8000704@oracle.com>>>
> >     >     Content-Type: text/plain; charset=ISO-8859-1; format=flowed
> >     >
> >     >     Look into docs in ocfs2 projects page. While there
> >     >     is no design doc, there is a presentation which lists
> >     >     out the changes.
> >     >
> >     >     http://oss.oracle.com/projects/ocfs2/documentation/
> >     >
> >     >     Sum Sha wrote:
> >     >     > Hi all,
> >     >     > Could someone point me to design doc for OCFS2? I could
> >     get OCFS
> >     >     V-1
> >     >     > design doc, but could not find any design doc for OCFS2. I
> >     read
> >     >     > somewhere that OCFS2 has got lots of design changes as
> >     comapared to
> >     >     > OCFS1.
> >     >     >
> >     >     > Thanks in advance.
> >     >     >
> >     >     > _______________________________________________
> >     >     > Ocfs2-devel mailing list
> >     >     > Ocfs2-devel at oss.oracle.com
> >     <mailto:Ocfs2-devel@oss.oracle.com>
> >     <mailto:Ocfs2-devel@oss.oracle.com
> >     <mailto:Ocfs2-devel@oss.oracle.com>>
> >     >     > http://oss.oracle.com/mailman/listinfo/ocfs2-devel
> >     >     <http://oss.oracle.com/mailman/listinfo/ocfs2-devel
> >     <http://oss.oracle.com/mailman/listinfo/ocfs2-devel>>
> >     >     >
> >     >
> >     >
> >     >
> >     >     ------------------------------
> >     >
> >     >     _______________________________________________
> >     >     Ocfs2-devel mailing list
> >     >     Ocfs2-devel at oss.oracle.com
> >     <mailto:Ocfs2-devel@oss.oracle.com>
> >     <mailto:Ocfs2-devel@oss.oracle.com
> >     <mailto:Ocfs2-devel@oss.oracle.com>>
> >     >     http://oss.oracle.com/mailman/listinfo/ocfs2-devel
> >     <http://oss.oracle.com/mailman/listinfo/ocfs2-devel>
> >     >
> >     >
> >     >     End of Ocfs2-devel Digest, Vol 25, Issue 10
> >     >     *******************************************
> >     >
> >     >
> >     >
> >
> ------------------------------------------------------------------------
> >
> >     >
> >     > _______________________________________________
> >     > Ocfs2-devel mailing list
> >     > Ocfs2-devel at oss.oracle.com <mailto:Ocfs2-devel@oss.oracle.com>
> >     > http://oss.oracle.com/mailman/listinfo/ocfs2-devel
> >     >
> >
> >
>

^ permalink raw reply	[flat|nested] 8+ messages in thread
* [Ocfs2-devel] Please help me in getting OCFS2 design doc.
  2006-05-08 13:23       ` Sum Sha
@ 2006-05-08 17:50         ` Sunil Mushran
  0 siblings, 0 replies; 8+ messages in thread
From: Sunil Mushran @ 2006-05-08 17:50 UTC (permalink / raw)
  To: ocfs2-devel

Sum Sha wrote:
> Thanks again for providing this information. I thought, we create
> volumes with ASM and then format those volumes with OCFS2 and then
> mount them. I probably missed it ;-)
>
> One more thing which I'd be interested to discuss is "heartbeat
> mechanism" and "self-fencing" behaviour of OCFS2.
>
> I have read that
> "An active node is deemed dead if it does not update its timestamp for
> O2CB_HEARTBEAT_THRESHOLD (default=7) loops"
>                                           and
> "A node self-fences if it fails to update its timestamp for
> ((O2CB_HEARTBEAT_THRESHOLD - 1) * 2) secs. The [o2hb-xx] kernel
> thread, after every timestamp write, sets a timer to panic the system
> after that duration. If the next timestamp is written within that
> duration, as it should, it first cancels that timer before setting up
> a new one"
>
> Here, the first case seems to be dependent on the second one, isn't
> it? If a node is not able to see other nodes' timestamp within
> (O2CB_HEARTBEAT_THRESHOLD * 2) time, then it assumes one of the
> following things:
>
> 1. The other node could not put timestamp within
> (O2CB_HEARTBEAT_THRESHOLD - 1) * 2 time and paniced itself.
>                                OR
> 2. The other node is actually dead and we give extra 2 seconds to
> detect that. Are we giving these extra 2 seconds to [hb-xx] kernel
> thread for detecting this scenario?
>
>   
I am not sure what the difference is between the two. The other nodes don't
care what the reason is for the node not to be able to update the hb. 
All they
care is whether it was updated or not. Also, the extra 2 secs should be 
viewed
from the other side... the node panics itself 2 secs before the other 
will deem
it dead and kick it off the cluster.

^ permalink raw reply	[flat|nested] 8+ messages in thread
end of thread, other threads:[~2006-05-08 17:50 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2006-05-02 14:15 [Ocfs2-devel] Please help me in getting OCFS2 design doc Sum Sha
2006-05-02 17:11 ` Sunil Mushran
2006-05-03 11:18   ` Sum Sha
2006-05-03 23:51     ` Sunil Mushran
2006-05-08 13:23       ` Sum Sha
2006-05-08 17:50         ` Sunil Mushran
  -- strict thread matches above, loose matches on Subject: below --
2006-04-27 14:50 Sum Sha
2006-04-27 17:03 ` Sunil Mushran

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