Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
//forwarding this email to the mailing list// OK Tom, I'm slowly getting the picture. Maybe you (or anyone) could give me a boost, by telling me (us) how you would set up the disks/filesystems? Assuming: 2 node system 1 disk per node Gb NIC w/crossover cable 100Mb NIC for the network wanting: data encrypted on disk a (large) portion of disk mirrored between nodes for the purpose of: hosting several virtual machines where one node can host all machines during failover ============== Thanks, Colin. On Saturday 06 September 2008 12:20:03 you wrote: > On Sat, 6 Sep 2008, Colin wrote: > > Tom, I think you are correct there. > > > > I guess a cluster-aware filesystem would only be needed if all the > > virtual machines were on the same logical volume, and both nodes would be > > running different VM's from that LV? > > as far as I know, you need the cluster aware filesystem if multiple nodes > have the same filesystem mounted. So, for example, if you were using image > files (yuck) stored on a single filesystem and handed out by each dom0 to > guests on both nodes you would need it... as both dom0's have the > filesystem mounted. > > That isn't to say that the cluster aware lvm version isn't a good thing... > if both dom0's see the drbd resource, they better agree on how you've > sliced it up into logical volumes... but the domUs using the LV slices can > simply run a normal filesystem and get much better performance as they > don't have to do any checking/locking to see if another node is messing > with the same files. > > -Tom > > > I wonder if that kind of setup would be better or worse? > > (Maybe more simple because only one LV is needed, but worse because of > > the unnecessary complication of using a 'distributed lock manager'?) > > > > Colin. > > > > On Saturday 06 September 2008 11:35:42 you wrote: > >> On Fri, 5 Sep 2008, Colin wrote: > >>> Well it came in to play when I had one large 'resource' configured > >>> (Primary/Primary, if I didn't mention that yet), and I wanted to create > >>> several 'logical volumes' on that resource, so that my multiple virtual > >>> machines would have a defined sized box to live in. This brought me to > >>> the DRBD User's Guide, Chap. 10, Using GFS with DRBD. > >>> On the page: Configuring LVM to recognize the DRBD resource, it states > >>> that GFS uses CLVM. > >> > >> AFAICS, you do NOT need a cluster-aware filesystem. You're not going to > >> have multiple nodes writing to the same filesystem at the same time. If > >> you're given each virtual machine a chunk of space to call it's own, > >> then that virtual machine will either be on one node or the other... and > >> it will be the only writer to that chunk of space... yes/no? > >> > >> -Tom >