Emmanuel Noobadmin wrote, On 08/03/2010 11:13 AM:
From what I understand, I cannot do the equivalent of network RAID 1 with a normal DRBD/HB style cluster. Gluster with replicate appears to do exactly that. I can have 2 or more storage servers with real time duplicates of the same data so that if any one fails the cluster does not run into problem. By using gluster distribute over pairs of server, it seems that I can also easily add more storage by adding more pairs of replicate server.
To have more than one active server with DRBD (or other disk type shared between active machines) you need to be using a file system which supports shared disk resources. http://www.drbd.org/docs/about/ http://www.drbd.org/users-guide-emb/s-dual-primary-mode.html http://www.drbd.org/users-guide-emb/ch-gfs.html http://www.drbd.org/users-guide-emb/ch-ocfs2.html
and perhaps using Gluster (Raid0 on net) with DRBD (Raid 1 on net) as disk space to get HA into Gluster? http://www.drbd.org/users-guide-emb/ch-xen.html
Note that it has been a while since I have ran DRBD on a set of systems and I only ran in active-passive with ext3, so I only know about the resources above that someone would want to look at.