[Linux-cluster] architecture discussion -- NFS clustering with iSCSI

[Gordan Bobic]

Terry wrote:

>>>> By and large, none. GFS is fairly unique in the way it does things. The
>>>> rest of the world hasn't really caught up yet. ;-)
>>> what exactly does it do that's unique?
>> I appear to stand corrected as per the other post, with SGI and IBM
>> offerings that do similar things, but providing shared r/w access to a
>> common physical volume isn't exactly common.
>>
>>>> I'm not sure why OCFS keeps coming up, since it's not a normal, general
>>>> purpose file system. It's only useful for putting Oracle DB volumes on it.
>>> ocfs2 is a general file system and has been available for quite some time
>>> (and is very easy to setup).
>> Fair enough. The documentation I had read on it seemed to imply otherwise,
>> which is why I went with GFS. I cannot say that I am in any way regretting
>> that choice. :-)
>>
> Well, I am having a heck of a time wrapping my head around how
> clustering and gfs are related.  My application is an N+1 type of
> configuration (grid computing).  I don't need any application
> clustering that cluster suite offers.  I just need a file system that
> they can all mount in read/write.  I might just have to get a couple
> of RHEL5 boxes up and going to fully understand this.  Is cluster
> suite and gfs included in RHEL5? Or how does that work?

You need the clustering component to be active in order to mount GFS 
file systems because the clustering subsystem is what maintains the 
quorum. You cannot multi-mount GFS without the cluster being active.

Gordan