RE: [Linux-cluster] Simplest 4 node GFS 6.1 cluster

[<JACOB_LIBERMAN Dell com>]

Troy,

What is the model/vendor of the switch? What are the models/vendors of
the servers? I ran into a similar problem in our lab (no network power
switches) and there are a few ways to get around that problem.

Thanks, jacob 

> -----Original Message-----
> From: linux-cluster-bounces redhat com 
> [mailto:linux-cluster-bounces redhat com] On Behalf Of Troy Dawson
> Sent: Thursday, June 23, 2005 8:43 AM
> To: linux clustering
> Subject: [Linux-cluster] Simplest 4 node GFS 6.1 cluster
> 
> Hello,
> I've really been trying to figure this out from the 
> documentation, and if it's in there, please point me at it.
> 
> Here is what I want to do.  I have 4 machines, all connected 
> to the same SAN disk.  1 machine will be the only machine 
> that can read and write to the disk.  The other 3 will be 
> read only.  The read only machines will be the only ones that 
> have outside services running, such as ftp, nfs, rsync.
> 
> I don't have a reliable 5th machine.  So I don't have a way 
> to do an external lock manager.
> 
> I don't want any failover, but I also don't want a single 
> point of failure.  Basically if one of the read only machines 
> goes dead, then it's dead, nothing takes it's place, but the 
> other machines can go right on working.  If the read, write 
> machine goes dead, then it's dead, but the read only machines 
> can go right on doing what they normally do.  And if two or 
> three machines die, I still want the one to still be able to 
> at least read the data.
> 
> This idea of fencing is what's throwing me off.  If I'm 
> reading things right, I can't do group GFS without them being 
> in a cluster, and they can't be in a cluster without doing 
> fencing.  But the fencing seems to just allow the various 
> machines to take over for one another.
> 
> I also don't have access to the SAN switch, other than my 
> machines plug into it.  It's essentially a black box.  These 
> machines also don't have any way to remotely turn power on an off.
> 
> Is GFS what I really want?  I've tried just standard ext3, 
> but I was getting a caching problem with my read only 
> machines.  Do I just want to try and fix my caching problem?
> 
> Troy Dawson
> --
> __________________________________________________
> Troy Dawson  dawson fnal gov  (630)840-6468 Fermilab  
> ComputingDivision/CSS  CSI Group 
> __________________________________________________
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