We're trying to setup a dual-primary DRBD environment, with a shared disk with either OCFS2 or GFS. The environment is a Centos 5.3 with DRBD82 (but also tried with DRBD83 from testing) . Setting up a single primary disk and running bonnie++ on it works. Setting up a dual-primary disk, only mounting it on one node (ext3) and running bonnie++ works When setting up ocfs2 on the /dev/drbd0 disk and mounting it on both nodes, basic functionality seems in place but usually less than 5-10 minutes after I start bonnie++ as a test on one of the nodes , both nodes power cycle with no errors in the logfiles, just a crash. When at the console at the time of crash it looks like a disk IO (you can type , but actions happen) block happens then a reboot, no panics, no oops , nothing. ( sysctl panic values set to timeouts etc ) Setting up a dual-primary disk , with ocfs2 only mounting it on one node and starting bonnie++ causes only that node to crash. On DRBD level I get the following error when that node dissapears drbd0: PingAck did not arrive in time. drbd0: peer( Primary -> Unknown ) conn( Connected -> NetworkFailure ) pdsk(UpToDate -> DUnknown ) drbd0: asender terminated drbd0: Terminating asender thread That however is an expected error because of the reboot. At first I assumed OCFS2 to be the root of this problem ..so I moved forward and setup an ISCSI target on a 3rd node, and used that device with the same OCFS2 setup. There no crashes occured and bonnie++ flawlessly completed it test run. So my attention went back to the combination of DRBD and OCFS I tried both DRBD 8.2 drbd82-8.2.6-1.el5.centos kmod-drbd82-8.2.6-2 and the 83 variant from Centos Testing At first I was trying with the ocfs2 1.4.1-1.el5.i386.rpm verson but upgrading to 1.4.2-1.el5.i386.rpm didn't change the behaviour Anyone has an idea on this ? How can we get more debug info from OCFS2 , apart from heartbeat tracing which doesn't learn me nothing yet .. in order to potentially file a valuable bug report. thnx in advance Kris