Fwd: [ILUG] iSCSI & Shared Storage Question ---------- Forwarded message ----------
From: John Moylan 
Date: Nov 15, 2007 11:33 AM
Subject: Re: [ILUG] iSCSI & Shared Storage Question
To: evhq@clubi.ie, evhq@jakma.org


Seems to be some confusion here bout GFS

I disagree with Paul about veering off of paths etc. GFS serves a
valid purpose and is enterprise ready and well integrated into the
Redhat/Centos Stack.

It is not an alternative to NFS, NFS would normally be run ontop of
GFS. GFS just handles concurrency for reads/writes. You still have to
replicate your data - normally using whatever came with your SAN or
something like Veritas's continuous access system.

CLVM won't allow you to stripe accross SAN's in a fabic it just
applies LVM changes the nodes in your SAN that get picked up on by all
of the attached hosts.

Good starting point (the redhat Cluster NFS cookbook)
http://sources.redhat.com/cluster/doc/nfscookbook.pdf .

My previous advice stands, set up a lab and break and fix the system
until you know it's strengths and weaknesses and are comfortable with
the idea of having to support it if something goes wrong - same goes
for any system though. - non clustered NFS included.

John


On Nov 15, 2007 12:09 AM,   wrote:
> On Wed, 14 Nov 2007, evhq@clubi.ie wrote:
>
> > NFS + rsync of your data to a backup NFS server, with manual failover is a
> > really safe bet and will take very little time to setup and maintain..
>
> Oh, one thing to bear in mind that those distributed, multi-node FSes
> don't necessarily provide redundancy (distributed redundancy isn't
> entirely trivial).
>
> NFS and an automounter can provide the same effect (a consistent
> namespace to a bunch of files spread across different machines).
>
> regards,
> --
> Paul Jakma      evhq@clubi.ie   evhq@jakma.org  Key ID: 64A2FF6A
> Fortune:
> NEWS FLASH!!
> Today the East German pole-vault champion became the West German pole-vault
> champion.
>
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