= Setting up Cluster GFS2 using Pacemaker =

''*This page does not contains the exact configuration of current Pacemaker on the KNU Cluster, but at least provides a basic configuration flow with examples.''

Configuration:
{{{
pcs cluster auth a1 a2 s1 g1
pcs cluster setup --start --enable --name pcs_cluster a1 a2 s1 g1

pcs stonith create pn7320 fence_altusen_snmp ipaddr=10.25.255.XXX community=XXX pcmk_host_list="s1,s2,s3,s4,s5,s6,s7,s8,s9,s10,a1,a2,g1,g2" \
  pcmk_host_map="s1:S1P1;s2:S1P2;s3:S1P3;s4:S1P4;s5:S1P5;s6:S1P6;s7:S1P7;s8:S1P8;s9:S1P13;s10:S1P14;a1:S1P15;a2:S1P16;g1:S1P17;g2:S1P18" \
  op monitor interval=60s
pcs stonith create ipmi_s1 fence_ipmilan ipaddr=10.25.255.1 login=ADMIN passwd=XXX pcmk_host_list=s1 op monitor interval=60s
pcs stonith level add 1 s1 ipmi_s1
pcs stonith level add 2 s1 pn7320
pcs stonith level add 1 a1 pn7320
pcs stonith level add 1 a2 pn7320
pcs stonith level add 1 g1 pn7320

pcs constraint location ipmi_s1 avoids s1=INFINITY

pcs property set no-quorum-policy=freeze
pcs resource create dlm   ocf:pacemaker:controld op monitor interval=30s on-fail=fence clone interleave=true ordered=true
pcs resource create clvmd ocf:heartbeat:clvm     op monitor interval=30s on-fail=fence clone interleave=true ordered=true
pcs constraint order start dlm-clone then clvmd-clone
pcs constraint colocation add clvmd-clone with dlm-clone

pcs resource create gfs2home Filesystem device=/dev/GFS2HOME/HOME directory=/home fstype=gfs2 "options=relatime" op monitor interval=10s on-fail=fence clone interleave=true
pcs constraint order start clvmd-clone then gfs2home-clone
pcs constraint colocation add gfs2home-clone with clvmd-clone
}}}

Clustered IP for a-nodes for load balancing and failover:
{{{
pcs resource create a-nodes-IP ocf:heartbeat:IPaddr2 ip=10.25.240.250 cidr_netmask=32 op monitor interval=10s
pcs resource clone a-nodes-IP clone-max=2 clone-node-max=2 globally-unique=true
pcs resource update a-nodes-IP clusterip_hash=sourceip
pcs constraint location a-nodes-IP-clone prefers a1=200 a2=200
pcs constraint location a-nodes-IP-clone avoids s1 s2 g1
pcs resource update a-nodes-IP-clone resource-stickiness=-1
}}}

DRBD device for /opt
{{{
yum -y install drbd-pacemaker drbd-udev
cat <<END > /etc/drbd.d/a-nodes-opt.conf
resource drbdopt {
  protocol C;
  meta-disk internal;
  device /dev/drbd1;
  syncer {
    verify-alg sha1;
  }
  net {
    allow-two-primaries;
  }
  on a1.cluster.univ.kiev.ua {
    disk "/dev/disk/by-path/pci-0000:04:02.0-scsi-0:0:3:0";
    address 10.25.240.251:7789;
  }
  on a2.cluster.univ.kiev.ua {
    disk "/dev/disk/by-path/pci-0000:04:02.0-scsi-0:0:3:0";
    address 10.25.240.252:7789;
  }
}
END

drbdadm create-md drbdopt
modprobe drbd
drbdadm up drbdopt
drbdadm primary --force drbdopt
cat /proc/drbd
}}}

DRBD Master/Master with Pacemaker ('''Obsolete: configured as Master/Slave now''')
{{{
echo drbd > /etc/modules-load.d/drbd.conf
pcs resource create drbd-opt ocf:linbit:drbd drbd_resource=drbdopt op monitor interval=60s
pcs resource master drbd-opt-clone drbd-opt master-max=2 master-node-max=1 clone-max=2 clone-node-max=1 notify=true
pcs constraint location drbd-opt-clone prefers a1 a2
pcs constraint location add location-drbd-opt-clone-avoids-s1 drbd-opt-clone s1 -INFINITY resource-discovery=never
pcs constraint location add location-drbd-opt-clone-avoids-s2 drbd-opt-clone s2 -INFINITY resource-discovery=never
pcs constraint location add location-drbd-opt-clone-avoids-g1 drbd-opt-clone g1 -INFINITY resource-discovery=never
}}}

GFS2 /opt on DRBD: ('''Obsolete: using ext4 now (more reliable with Master/Slave DRBD)''')
{{{
mkfs.gfs2 -p lock_dlm -j 2 -t pcs_cluster:a-nodes-opt /dev/drbd1
pcs resource create gfs2opt Filesystem device="/dev/drbd1" directory="/mnt/opt" fstype="gfs2"
pcs constraint colocation add gfs2opt with drbd-opt-clone INFINITY with-rsc-role=Master
pcs constraint colocation add gfs2opt with dlm-clone INFINITY
pcs constraint order promote drbd-opt-clone then start gfs2opt
pcs constraint order dlm-clone then gfs2opt
pcs resource clone gfs2opt
}}}

NFS server failover:
{{{
pcs resource create a-nodes-nfs-IP IPaddr2 ip=10.25.240.200 cidr_netmask=24 iflabel=nfs arp_bg=true meta resource-stickiness=100 op monitor interval=5s
pcs constraint colocation add a-nodes-nfs-IP with gfs2opt-clone INFINITY
pcs resource create a-nodes-nfs-export ocf:heartbeat:nfsserver nfs_ip=10.25.240.200 nfs_shared_infodir=/mnt/opt/var/lib/nfs op monitor interval=5s 
pcs constraint colocation add a-nodes-nfs-export with a-nodes-nfs-IP INFINITY
}}}

Status check commands in addition to {{{pcs status}}}:
{{{
corosync-cmapctl | grep members
corosync-cfgtool -s
crm_verify -L -V
}}}

DRBD /opt recovery:
{{{
pcs resource disable drbd-opt-clone
drbdadm up drbdopt
[node with up to date data] drbdadm primary drbdopt
e2fsck -y /dev/drbd1
[node with discarded data] drbdadm secondary drbdopt
[node with discarded data] drbdadm connect --discard-my-data drbdopt
[node with up to date data] drbdadm connect drbdopt
pcs resource enable drbd-opt-clone
}}}

Useful for debug:
{{{
crm_simulate -sL (resource locations weights)
}}}
Logs:
 - check {{{/var/log/messages}}} on every node