[Ocfs2-users] Combining OCFS2 with Linux software RAID-0?
Luis Freitas
lfreitas34 at yahoo.com
Mon Dec 14 23:46:45 PST 2009
Sunil,
I am getting too old for all these cluster stacks! Seems that heartbeat2 is deprecated...
Can ocfs2 be integrated with pacemaker in the same way as it was possible with heartbeat2 on Suse 10? I know that the RedHat cluster stack cannot, so I used to consider this as an additional feature for Suse Linux.
Best Regards,
Luis Freitas
--- On Mon, 12/14/09, Sunil Mushran <sunil.mushran at oracle.com> wrote:
From: Sunil Mushran <sunil.mushran at oracle.com>
Subject: Re: [Ocfs2-users] Combining OCFS2 with Linux software RAID-0?
To: "Luis Freitas" <lfreitas34 at yahoo.com>
Cc: "Brian Kroth" <bpkroth at gmail.com>, ocfs2-users at oss.oracle.com
Date: Monday, December 14, 2009, 4:20 PM
That's old.
sles11 has added the pacemaker cluster stack that works with clvm.
Luis Freitas wrote:
> Brian,
>
> Hmm, I was not aware of this. Seems Novel uses other volume
> manager, called EVMS, not CLVM (?).
>
> From:
> http://wiki.novell.com/index.php/Linux_Data_Management
>
>
>
> Some Open Source OCFS2 Features
>
> Oracle Linux Certification matrix
> <http://www.novell.com/products/server/oracle/matrix.html>
> OCFS2 project web site <http://oss.oracle.com/projects/ocfs2/>
> OCFS2 Development Roadmap <http://oss.oracle.com/osswiki/OCFS2/Roadmap>
> Oracle Cluster File System v2 (OCFS2) is an open source cluster
> management and
> ....
>
> * No exclusive write lock capability yet (now every lock request
> returns: successful). This feature is candidate for SLE10 SP2
> (Q1 2008).
> * OCFS2 on top of a software mirror is not supported yet
> * *Can be managed by EVMS *
>
> *....*
>
> * OCFS2 offers integration with heartbeat2. Heartbeat2 offers a
> Resource Agent 'md group take over'. (which enables fail-over of
> host based mirroring of SAN volumes), but OCFS2 on top of a
> software mirror is not supported.
>
> ...
>
> Best Regards,
> Luis Freitas
>
> --- On *Fri, 12/11/09, Brian Kroth /<bpkroth at gmail.com>/* wrote:
>
>
> From: Brian Kroth <bpkroth at gmail.com>
> Subject: Re: [Ocfs2-users] Combining OCFS2 with Linux software RAID-0?
> To: "Luis Freitas" <lfreitas34 at yahoo.com>
> Cc: "Patrick J. LoPresti" <lopresti at gmail.com>,
> ocfs2-users at oss.oracle.com
> Date: Friday, December 11, 2009, 2:09 PM
>
> Luis Freitas <lfreitas34 at yahoo.com
> <http://us.mc514.mail.yahoo.com/mc/compose?to=lfreitas34@yahoo.com>>
> 2009-12-11 05:40:
> > Patrick,
> >
> > Depending on what you are using, you could use the volume manager
> > to do the striping, but you need to use CLVM. So if you can,
> go for
> > Heartbeat2+CLVM+OCFS2, all integrated.
> >
> > Not sure but I think Heartbeat2+OCFS2 is only available on the
> > vanilla kernels, not on the enterprise ones. Maybe Suse has
> > support, I don't know, you will have to check.
> >
> > Best Regards,
> > Luis Freitas
>
> Just to elaborate on these comments. Last time I checked CLVM
> required
> the openais/cman cluster stack, which neither heartbeat nor ocfs2 use
> (by default). The userspace stack option for ocfs2 in recent mainline
> kernels added support for the openais stack and pacemaker is
> required to
> make heartbeat work with that rather than use it's own cluster stack.
>
> Now, you can do an basic LVM linear span, concatenation, or
> whatever you
> want to call it without any cluster stack, so long as it's not striped
> and so long as you heed Sunil's warning about fat fingering changes to
> the thing while more than one host is using it.
>
> That means that if you want to add another LUN to the span you
> can't do
> it on the fly. You have to do something like this:
>
> # On all nodes:
> umount /ocfs2
>
> # On all nodes but one:
> vgchange -an ocfs2span
> # Or, to be extra safe:
> halt -p
>
> # On the remaining node:
> vgextend ocfs2span /dev/newlun
> lvextend -l+100%FREE /dev/mapper/ocfs2span-lv
> tunefs.ocfs2 -S /dev/mapper/ocfs2span-lv
>
> # You might actually need the fs mounted for that last bit, I forget.
> # Probably a fsck somewhere in there would be wise as well.
>
> # Bring the other nodes back up.
>
> Brian
>
> > --- On Wed, 12/9/09, Patrick J. LoPresti <lopresti at gmail.com
> <http://us.mc514.mail.yahoo.com/mc/compose?to=lopresti@gmail.com>>
> wrote:
> >
> > From: Patrick J. LoPresti <lopresti at gmail.com
> <http://us.mc514.mail.yahoo.com/mc/compose?to=lopresti@gmail.com>>
> > Subject: [Ocfs2-users] Combining OCFS2 with Linux software RAID-0?
> > To: ocfs2-users at oss.oracle.com
> <http://us.mc514.mail.yahoo.com/mc/compose?to=ocfs2-users@oss.oracle.com>,
> linux-raid at vger.kernel.org
> <http://us.mc514.mail.yahoo.com/mc/compose?to=linux-raid@vger.kernel.org>
> > Date: Wednesday, December 9, 2009, 9:03 PM
> >
> > Is it possible to run an OCFS2 file system on top of Linux
> software RAID?
> >
> > Here is my situation. I have four identical disk chassis that
> perform
> > hardware RAID internally. Each chassis has a pair of fiber
> channel
> > ports, and I can assign the same LUN to both ports. I want to
> connect
> > all of these chassis to two Linux systems. I want the two Linux
> > systems to share a file system that is striped across all four
> chassis
> > for performance.
> >
> > I know I can use software RAID (mdadm) to do RAID-0 striping
> across
> > the four chassis on a single machine; I have tried this, it works
> > fine, and the performance is tremendous. I also know I can
> use OCFS2
> > to create a single filesystem on a single chassis that is shared
> > between my two Linux systems. What I want is to combine these two
> > things.
> >
> > Suse's documentation
> > ([1]http://www.novell.com/documentation/sles11/stor_admin/?page=/documentation/sles11/stor_admin/data/raidyast.html)
> > says:
> >
> > "IMPORTANT:Software RAID is not supported underneath clustered
> file
> > systems such as OCFS2, because RAID does not support concurrent
> > activation. If you want RAID for OCFS2, you need the RAID to be
> > handled by the storage subsystem."
> >
> > Because my disk chassis already perform hardware RAID-5, I
> only need
> > Linux to do the striping (RAID-0) in software. So for me,
> there is no
> > issue about "which node should rebuild the RAID" etc. I
> understand
> > that Linux md stores meta-data on the partitions and is not
> cluster
> > aware, but will this create problems for OCFS2 even if it is
> just RAID
> > 0?
> >
> > Has anybody tried something like this? Are there alternative
> RAID-0
> > solutions for Linux that would be expected to work?
> >
> > Thank you.
> >
> > - Pat
> >
> > _______________________________________________
> > Ocfs2-users mailing list
> > [2]Ocfs2-users at oss.oracle.com
> <http://us.mc514.mail.yahoo.com/mc/compose?to=Ocfs2-users@oss.oracle.com>
> > [3]http://oss.oracle.com/mailman/listinfo/ocfs2-users
> >
> > References
> >
> > Visible links
> > 1.
> http://www.novell.com/documentation/sles11/stor_admin/?page=/documentation/sles11/stor_admin/data/raidyast.html
> > 2. file:///mc/compose?to=Ocfs2-users@oss.oracle.com
> <http://us.mc514.mail.yahoo.com/mc/compose?to=Ocfs2-users@oss.oracle.com>
> > 3. http://oss.oracle.com/mailman/listinfo/ocfs2-users
>
> > _______________________________________________
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>
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