October 05, 2003
OpenGFS, heartbeat and Samba
Update 9 October - it works now, although not quite as I pondered below ... See here for details
I managed to get a part of my new OpenGFS Linux file server cluster working on Thursday night. One of the servers now loads the memexp and ogfs modules, starts the memexpd lock server and mounts the ogfs drive at startup, and makes it available as a Samba share. Simple enough - I can now map a network drive to the 1.1Tb drive using Win XP.
It manages this through the heartbeat mechanism, with the two servers, fred and barney, configured so that fred is the preferred server. The bit that doesn't work yet is the failover, so that if you shutdown fred, barney should detect the heartbeat failure and take over file serving, and with only a small interruption should restart the lock server, mount the ogfs drive and make the Samba share available again. The only problem is that the ogfs mount takes a hostdata option. I currently have this set in the haresources file to be the ip address of each server, which goes against the stern advice in the haresources header to make sure that the files are the same on each cluster member.
Well, it doesn't work. If fred fails, barney can't mount the ogfs drive. I'm guessing there is some stomith/stonith stuff to be done here. do_manual, perhaps?
It only occurred to me as I was leaving the office that perhaps this hostdata parameter could be the cluster ip address, not the ip address of each individual cluster member. I'll try it tomorrow, anyway. I wonder what will happen to the lock info, though, seeing as I'm not using the -d option when I start memexp ... could be messy.
Posted by daen at October 5, 2003 03:16 PM