re[2]: [SSI] Question about CFS and GFS

[Greg F. <freemyer@NorcrossGroup.com>]

One brief example:

8 nodes with a SCSI based shared storage solution.

4 nodes redundantly connected to a pair of SCSI hubs connected connected to the =
storage system.

The other 4 have no connection to the shared storage.  (I'm not familiar with =
SCSI hubs that support more than 4 servers.)

Now the first 4 could use GFS to directly access the shared storage.

The other 4 would use the CFS to talk to the storage. =20

This obviously would require CFS to be layered on top of GFS.

=3D=3D
The same thing would also apply to FC. =20

Lets say I want to build a 10 node cluster.  Having 8 nodes on the SAN is a lot =
cheaper than having 10 nodes on the SAN.

i.e.  An 8-port Brocade switch is a lot cheaper than a 16-port Brocade Switch.

=3D=3D=3D
Also, there is the issue of scalability.  (I'm only familiar with the Compaq =
Array Controllers, so ... )

I believe Compaq's EMA16000 only supports 30 or so hosts (or nodes).  And the =
EMA16000 is well above $100K

If you want to build a 100 node cluster with pure GFS, you have to step up to =
their just released Enterprise Virtual Array (EVA).  I don't know what its =
pricing is, but I would not be surprised to find out your in the $1M range.

Even the EVA tops out at 1000 hosts.

OTOH, if you have CFS layered on top of GFS, you can continue to expand your =
cluster, even if you have maxed out your Array Controller's connected host =
limit.

Greg
=3D=3D=3D=3D=3D
Greg Freemyer
Internet Engineer
Deployment and Integration Specialist
The Norcross Group
www.NorcrossGroup.com

 >>  On Fri, Nov 16, 2001 at 02:42:39PM -0500, Greg Freemyer wrote:
 >>  > No mention was made of layering CFS over GFS. =20
 >>  >=20
 >>  > I hope that CFS will indeed layer over GFS.

 >>  Why?  I doesn't really make sense to me..

 >>      Christoph

 >>  --=20
 >>  Of course it doesn't work. We've performed a software upgrade.





Greg Freemyer
Internet Engineer
Deployment and Integration Specialist
The Norcross Group
www.NorcrossGroup.com