On Mon, Feb 27, 2012 at 02:51:54PM -0600, list@airstreamcomm.net wrote:
You could also look at GPFS (http://www-03.ibm.com/systems/software/gpfs/), which is not open source but it's apparently rock solid and I believe supports multisite clustering.
GPFS supports different modes of clustering. I think the appropriate solution here would be to deploy a single cluster spanning 3 sites (3. site is needed for quorum node, two sites can't work because you can't protect it from split brain). The simplest config would then be 3 nodes (but you could have any number of nodes at each site):
quorum node1 on site1 with a local disk (or local SAN-disk) as Network Shared Disk (NSD)
quorum node2 on site2 with a local disk (or local SAN-disk) as Network Shared Disk (NSD)
quorum node3 on site3The filesystem would be replicated (over IP) between the disk on site1 and site2. Should one site go down, the other site would survive as long as it could still see the quorum node on site3. After a site has been down, one would need to sync up the NSDs (mmrestripefs) to re-establish the replication of any blocks that has been changed while it was down.
-jf