> > You have some interesting and different ideas here: > > 1.- Shared storage with non-clustered filesystem: i have no experience > with HA-LVM, i have just checked its knowledge base on RHEL to refresh > my ideas. > > If i'm not wrong, what you want is to have a shared storage with > protection from concurrent mounts for your non-clustered filesystems, > but EVEN for admins doing, by hand, erratic mounts, am i right? Yes, that's it. > You can use a different approach to HA-LVM with CLVMD and a resource > script i have developed called "lvm-cluster". You can find it here: > > https://www.redhat.com/archives/cluster-devel/2009-June/msg00065.html > > It's not included in the main project yet, but some people in the list > are testing it successfully. > > Actually it would not avoid an admin doing, by hand, an erratic mount > but a bugzilla ticket has been opened by Brem Belguebli to fix an LVM > issue that is causing that behaviour. Apart from this admin issue, the > script would protect the concurrent mount of your filesystem by the > usage of the LVM layer. > > I do like more this approach because you don't need to generate new > initrd images for your nodes every time you configure new volumes to be > into the HA-LVM. Hum... that's good too. By the way, I was concerned about that requisite, which is absolutely not much pleaseant to do. Anyway, I'm trying to set up your script here, but I realized that actualy I still don't know how to do that. =/ (I'm using that tool called Luci, which looks good, specialy to someone that knows almost nothing about cluster. =) Ok, I have defined a script resource with the path of your script, and I guess that now I have to create a service, that's it? But how, if I don't have a single service to be watched. (Actualy, my service is my whole server, we could say.) Could you give me a configuration example? I'm really confused here yet. Wait, should I write a script for this task and use it on service configuration? I have tought about a script that always returns OK to verify-all, and status, and lauch VMs for start. Does it make any sense? > 2.- Communications interruption and split-brain: you should use some > fencing system to make the 2nd node "kill" the main one and take the > resources. Ok, I have understood that there's no way to avoid that problem unless turning off a server. Anyway, this is acceptable, once I don't expect such a situation happening oftenly. > Having the main node booted back again AND the comms not reestablished > will cause you a split-brain again, with a new fencing action. I usually > do not set cluster services (CMAN, RGMANAGER, etc.) to be automatically > started on the nodes. I mean they must be re-run and activated by an > admin. > > In the other hand you can use a Quorum Disk, provided my CMAN too, as > the 3rd vote on your cluster and keep the quorum. I use both approaches > at the same time (no auto-start of cluster services and qdisk). > > 3.- Communications channels: there's no way to set on CMAN more than one > comm channel, but you can set more than one network interface to be part > of that channel, via bonding. I think this is one of the lacks of CMAN > actually. > > I hope this helps. Just ask whatever you want. > Thank you, very much. -- Linux-cluster mailing list Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster
