[SATLUG] evms command line...

John Pappas j at jvpappas.net
Tue Sep 8 14:46:53 CDT 2009

On Tue, Sep 8, 2009 at 12:02, Enrique Sanchez <esanchezvela.satlug at gmail.com
> wrote:

> On Tue, Sep 8, 2009 at 11:45 AM, John Pappas<j at jvpappas.net> wrote:
> > On Mon, Aug 31, 2009 at 03:09, Enrique Sanchez <
> > esanchezvela.satlug at gmail.com> wrote:
> >
> >> On Sun, Aug 30, 2009 at 11:09 AM, John Pappas<j at jvpappas.net> wrote:
> >>
> >> We need to provide highly available application and database servers,
> >> the database servers will be using Oracle RAC using ocfs2
> >>
> > Ok, so native LVM cannot be used due to Cluster locking issues (Standard
> > has a single system lock setup), and I am not sure if CLVM (Cluster LVM)
> is
> > multi-active capable (Reading...)
> right now I am not looking at the active-active scenario, that would
> be later. thnx.....

So you have a standard active/passive (failover) cluster set up for
Application and RAC (Infers Active/Active) for DB, right?

> >  I am thinking that standard LVM can be used via import/export scripts in
> the failover policy.
> that's an idea, will explore it now. thank you.,

This would only apply to the Application cluster.  The RAC would have to be
run differently.  From my cursory research, CLVM looks like the VGs can be
shared amongst participating nodes (comm is done via CLVMD over the network,
not sure what best practice is, since most clusters have at least 1 client
facing network and at least 1 cluster only network, so not sure if the
cluster.conf handles nodes with more than 1 ip address.  Would assume so,
but have not tried it.

> I get a bunch of 8.43 GB EMC Shares and I need to group them together
> by class ( Tier1, Tier2 and T3) on volume groups.

That makes sense, T1 VGs, T2 VGs, T3 VGs.  Would not have MixTier VG (as
that could lead to badness)

> > That makes sense, AFAIK RAC (and most standard cluster types) requires
> > shared block storage (FC/iSCSI/etc) most do not function well with shared
> > file-level (NFS or similar) due to the locking mechanisms involved.
> Oracle RAC works well with GPFS (IBM's but that costs an arm and a leg).

Some would argue that the licensing required to run RAC costs an Arm + Leg +
Soul to begin with, so adding GPFS would leave no legs nor arms.  Not sure
if GFS (RedHat Global FS) could help here either.  Maybe even Polyserve (Not
sure of Oracle support though)

I agree, besides EVMS is only supported in SUSE10 and no longer
> developed, so adopting it right now is not what I would call
> brilliant.

Did not realize EVMS bit the dust.  I agree, building in another deprecated
dependancy would be poor planning.

> thank you again,
> Enrique.
> --

Sure.  <Shamelessness>  I freelance if there is room on the project

John P

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