On Sat, Oct 10, 2009 at 12:21:29PM -0700, Madison Kelly wrote: > Mike Cardwell wrote: > > Madison Kelly wrote: > > > >> Until now, I've been building 2-node clusters using DRBD+LVM for the > >> shared storage. I've been teaching myself clustering, so I don't have > >> a world of capital to sink into hardware at the moment. I would like > >> to start getting some experience with 3+ nodes using a central SAN disk. > >> > >> So I've been pricing out the minimal hardware for a four-node > >> cluster and have something to start with. My current hiccup though is > >> the SAN side. I've searched around, but have not been able to get a > >> clear answer. > >> > >> Is it possible to build a host machine (CentOS/Debian) to have a > >> simple MD device and make it available to the cluster nodes as an > >> iSCSI/SAN device? Being a learning exercise, I am not too worried > >> about speed or redundancy (beyond testing failure types and recovery). > > > > Yeah, that's possible. Just use iscsid to export the device. If this is > > just for testing/learning purposes have you considered using virtual > > machines to minimise the hardware footprint? You could have a single > > host machine that acts as the SAN, exporting a device using iscsid and > > three vm's running on top of VMWare server on the same machine which > > make up the cluster... > > Thanks! I was thinking that was what I could do, but I wanted to ask > before sinking a lot of time/money just to find out I was wrong. :) > > I thought about Xen VMs. I'll have to see if I can simulate things like > fence devices and such. Though, as good as virtualization is, I wonder > how close I could get to simulating real world? When I run into > problems, it would be another layer to wonder about. However, there is > no denying the cost savings! I will look into that more. Another option, at least with VMware, would be to create a shared disk that can be seen by all your VM's. A bit simpler than setting up iSCSI, though that would be a good thing to learn in it of itself... Ray -- Linux-cluster mailing list Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster
