Cluster LVM

sources:

https://www.suse.com/documentation/sle_ha/book_sleha/data/sec_ha_clvm_config.html

https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Cluster_Administration/s1-admin-manage-nodes-delete-add-cli-CA.html

https://www.ibm.com/developerworks/community/blogs/mhhaque/resource/RHCS_IBM_POWER.pdf?lang=zh

1. install necessary packages:

   apt-get install clvm cman

2. edit /etc/lvm/lmv.conf, set:

   mirror_logs_require_separate_pvs = 1
   locking_type = 3

3. set no wait time for quorum:

   echo "CMAN_QUORUM_TIMEOUT=0" >> /etc/default/cman

4. create config file /etc/cluster/cluster.conf and put it to all nodes:

   <cluster name="mycluster" config_version="1">
      <clusternodes>
        <clusternode name="10.0.0.23" nodeid="1">
            <fence>
            </fence>
        </clusternode>
        <clusternode name="10.0.0.112" nodeid="2">
            <fence>
            </fence>
        </clusternode>
      </clusternodes>
      <fencedevices>
      </fencedevices>
      <rm>
      </rm>
   </cluster>

5. start cman service and clvm service on all nodes:

   service cman start
   service clvm start

6. check that nodes are online in cluster:

   cman_tool nodes

   output should be:

   root@debian:~# cman_tool nodes
   Node  Sts   Inc   Joined               Name
      1   M      4   2015-10-30 09:34:43  10.0.0.23
      2   M      8   2015-10-30 09:36:04  10.0.0.112

7. assuming that /dev/sdb and /dev/sdc are volumes exported from SANs
8. create physical volumes:

   pvcreate /dev/sdb
   pvcreate /dev/sdc

9. create clustered volume group:

   vgcreate --clustered y guma_cerna /dev/sdb /dev/sdc

10. create mirrored lvm:

    lvcreate -n testovaci_lv -m1 -L 1.0g guma_cerna --nosync

    (–nosync means that data will not be synced upon creating - since the lv should not contain any data upon its creating its OK)

11. (optional) check that the volume were created succesfully on both SANs:

    lvs -a -o +devices

1. If deleting stop all cluster services on node e.g.:

   service stop clvm
   service stop cman

2. install cman clvm on new node(s) - don't forget to setup the /etc/lvm/lvm.conf file
3. attach SANs on new node(s)
4. edit the /etc/cluster/cluster.conf and increase serial:

   <cluster name="mycluster" config_version="2">
      <clusternodes>
        <clusternode name="10.0.0.23" nodeid="1">
            <fence>
            </fence>
        </clusternode>
        <clusternode name="10.0.0.112" nodeid="2">
            <fence>
            </fence>
        </clusternode>
        <clusternode name="10.0.0.110" nodeid="3">
            <fence>
            </fence>
        </clusternode>
     </clusternodes>
      <fencedevices>
      </fencedevices>
      <rm>
      </rm>
   </cluster>

5. distribute the file to ALL nodes in cluster and issue following command from any node:

   cman_tool version -r -S

6. to use previously created volumes those must be activated on new node:

   lvchange -a y /dev/guma_cerna/testovaci_lv

1. stop all cluster services and then stop cman service with parameter leave

   service clvm stop
   service cman stop leave