----- On Jun 6, 2016, at 8:17 PM, Digimer li...@alteeve.ca wrote:
> On 06/06/16 01:13 PM, Lentes, Bernd wrote: >> Hi, >> >> i'm currently establishing a two node cluster. I have a FC SAN and two >> hosts. My >> services are integrated into virtual machines (kvm). The vm's should reside >> on >> the SAN. >> The hosts are connected to the SAN via FC HBA. Inside the hosts i see already >> the volume from the SAN. I'd like to store each vm in a dedicated logical >> volume (with or without filesystem in the LV). >> Hosts are SLES 11 SP4. LVM2 and LVM2-clvm is installed. >> How do i have to "switch on" clvm ? Is locking_type=3 in /etc/lvm/lvm.conf >> all >> which is necessary ? > > That tells LVM to use cluster locking, you still need to actually > provide the cluster locking, called DLM. With the cluster formed (and > fencing working!), you should be able to start the clvmd daemon. > >> In both nodes ? > > Yes > >> Restart of the init-scripts afterwards sufficient ? > > No, DLM needs to be added to the cluster and be running. Ok. Does DLM takes care that a LV just can be used on one host ? cLVM just takes care that the naming is the same on all nodes, right ? > >> And how do i have to proceed afterwards ? >> My idea is: >> 1. Create a PV >> 2. Create a VG >> 3. Create several LV's > > If the VG is created while dlm is running, it should automatically flag > the VG as clustered. If not, you will need to tell LVM that the VG is > clustered (-cy, iirc). > >> And because of clvm i only have to do that on one host and the other host >> sees >> all automatically ? > > Once clvmd is running, any changes made (lvcreate, delete, resize, etc) > will immediately appear on the other nodes. > Ok. >> Later on it's possible that some vm's run on host 1 and some on host 2. Does >> clvm needs to be a ressource managed by the cluster manager ? > > Yes, you can live-migrate as well. I do this all the time, except I use > DRBD instead of a SAN and RHEL instead of SUSE, but those are trivial > differences in this case. > >> If i use a fs inside the lv, a "normal" fs like ext3 is sufficient, i think. >> But >> it has to be a cluster ressource, right ? > > You can format a clustered LV with a cluster unaware filesystem just > fine. However, the FS is not made magically cluster aware... If you > mount it on two nodes, you will almost certainly corrupt the FS quickly. > If you want to mount an LV on two+ nodes at once, you need a > cluster-aware file system, life GFS2. No. Pacemaker takes care that the FS is just mounted on one node. So it should not be a problem ? Bernd Helmholtz Zentrum Muenchen Deutsches Forschungszentrum fuer Gesundheit und Umwelt (GmbH) Ingolstaedter Landstr. 1 85764 Neuherberg www.helmholtz-muenchen.de Aufsichtsratsvorsitzende: MinDir'in Baerbel Brumme-Bothe Geschaeftsfuehrer: Prof. Dr. Guenther Wess, Dr. Alfons Enhsen, Renate Schlusen (komm.) Registergericht: Amtsgericht Muenchen HRB 6466 USt-IdNr: DE 129521671 _______________________________________________ Users mailing list: Users@clusterlabs.org http://clusterlabs.org/mailman/listinfo/users Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org
