Cluster LVM

install necessary packages:

apt-get install clvm cman

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

mirror_logs_require_separate_pvs = 1
locking_type = 3

set no wait time for quorum:

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

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

<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>
   </clusternodes>
   <fencedevices>
   </fencedevices>
   <rm>
   </rm>
</cluster>

start cman service and clvm service on all nodes:

service cman start
service clvm start

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

assuming that /dev/sdb and /dev/sdc are volumes exported from SANs

create physical volumes:

pvcreate /dev/sdb
pvcreate /dev/sdc

create clustered volume group:

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

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)