>>> Lars Marowsky-Bree <[email protected]> schrieb am 06.02.2013 um 13:38 in >>> Nachricht <[email protected]>: > On 2013-02-06T12:22:37, Ulrich Windl <[email protected]> > wrote: > > > > > colocation col_OCFS_cVG inf: _rsc_set_ ( cln_CFS ) cln_cLVM > > > > order ord_cVG_CFS inf: cln_cLVM ( cln_CFS ) > > > > > > Why not just: > > > > > > colocation col_OCFS_cVG inf: cln_CFS cln_cLVM > > > order ord_cVG_CFS inf: cln_cLVM cln_CFS > > > > The reason was "linear extensibility": If you have more than one CFS on > different LVs of the VG. > > I'm not sure I follow what you mean by that?
Just imagine you have more than one LV per VG, each containing a filesystem. Then each (LV and filesystem) should be treated as independently as possible from other pairs. Without the resource sets, you must either define a strict order which in unnecessary, or you must define multiple ordering constraints. To me, my solution seemed to be the elegant one. > > > > That ought to work. Probably clones and resource sets have a problem > > > here? > > From what I had read, the parenthesis don't make the difference. > > I have colocated clones and I've not seen that message, so my guess was > that this culd fix it. It would be helpful if anybody could explain what exactly causes the original message pengine: [9800]: notice: clone_rsc_colocation_rh: Cannot pair prm_A:1 with instance of cln_B What if the cluster would simply pair prm_A:1 with prm_B:1? The constraint as complained about was not eneterd by the user; it was created by the cluster, and then the cluster complains it cannot handle it. > > > > > DLM (Distributed Lock Manager) > > > > O2CB (OCFS2), needs DLM > > > > cLVM needs DLM > > > > LVM-LV needs cLVM > > > > OCFS2-filesystem needs both, O2CB and LVM-LV > > > > > > > > The pattern should be flexible enough to allow both, OFCS on top of an > LV, > > > as well as OCFS directly on a shared disk. And the pattern should only > define > > > contraints that are necessary, i.e. do not put everything in a group and > > > clone that group. > > > > > > The latter is the easiest solution that just works; where's the problem > > > with that? Too simple? ;-) > > > > Well, it's incomplete, as you can see simply by counting the number of > resources involved ;-) > > I still don't follow. You add all the file systems to the cloned group. > Problem solved? OK, why not be concrete then: If I have, let's say, 10 filesystems for virtual machines that should run independently on a selection of 7 nodes, how would your configuration look like? 10 cloned groups? Where do you put DLM, cLVM and O2CB? Obviously it cannot be inside the group. So maybe, please: Provide a working starting configuration, and then describe how to add on that starting configuration. Regards, Ulrich _______________________________________________ Linux-HA mailing list [email protected] http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems
