Anvil! Tutorial 3

Disabling Quorum

Note: Show the math.

With quorum enabled, a two node cluster will lose quorum once either node fails. So we have to disable quorum.

By default, pacemaker uses quorum. You don't see this initially though;

pcs property

Cluster Properties:
 dc-version: 1.1.9-0.1318.a7966fb.git.fc18-a7966fb
 cluster-infrastructure: corosync

To disable it, we set no-quorum-policy=ignore.

pcs property set no-quorum-policy=ignore
pcs property

Cluster Properties:
 dc-version: 1.1.9-0.1318.a7966fb.git.fc18-a7966fb
 cluster-infrastructure: corosync
 no-quorum-policy: ignore

Enabling and Configuring Fencing

We will use IPMI and PDU based fence devices for redundancy.

You can see the list of available fence agents here. You will need to find the one for your hardware fence devices.

pcs stonith list

fence_alom - Fence agent for Sun ALOM
fence_apc - Fence agent for APC over telnet/ssh
fence_apc_snmp - Fence agent for APC over SNMP
fence_baytech - I/O Fencing agent for Baytech RPC switches in combination with a Cyclades Terminal
                Server
fence_bladecenter - Fence agent for IBM BladeCenter
fence_brocade - Fence agent for Brocade over telnet
fence_bullpap - I/O Fencing agent for Bull FAME architecture controlled by a PAP management console.
fence_cisco_mds - Fence agent for Cisco MDS
fence_cisco_ucs - Fence agent for Cisco UCS
fence_cpint - I/O Fencing agent for GFS on s390 and zSeries VM clusters
fence_drac - fencing agent for Dell Remote Access Card
fence_drac5 - Fence agent for Dell DRAC CMC/5
fence_eaton_snmp - Fence agent for Eaton over SNMP
fence_egenera - I/O Fencing agent for the Egenera BladeFrame
fence_eps - Fence agent for ePowerSwitch
fence_hpblade - Fence agent for HP BladeSystem
fence_ibmblade - Fence agent for IBM BladeCenter over SNMP
fence_idrac - Fence agent for IPMI over LAN
fence_ifmib - Fence agent for IF MIB
fence_ilo - Fence agent for HP iLO
fence_ilo2 - Fence agent for HP iLO
fence_ilo3 - Fence agent for IPMI over LAN
fence_ilo_mp - Fence agent for HP iLO MP
fence_imm - Fence agent for IPMI over LAN
fence_intelmodular - Fence agent for Intel Modular
fence_ipdu - Fence agent for iPDU over SNMP
fence_ipmilan - Fence agent for IPMI over LAN
fence_kdump - Fence agent for use with kdump
fence_ldom - Fence agent for Sun LDOM
fence_lpar - Fence agent for IBM LPAR
fence_mcdata - I/O Fencing agent for McData FC switches
fence_rackswitch - fence_rackswitch - I/O Fencing agent for RackSaver RackSwitch
fence_rhevm - Fence agent for RHEV-M REST API
fence_rsa - Fence agent for IBM RSA
fence_rsb - I/O Fencing agent for Fujitsu-Siemens RSB
fence_sanbox2 - Fence agent for QLogic SANBox2 FC switches
fence_scsi - fence agent for SCSI-3 persistent reservations
fence_virsh - Fence agent for virsh
fence_vixel - I/O Fencing agent for Vixel FC switches
fence_vmware - Fence agent for VMWare
fence_vmware_soap - Fence agent for VMWare over SOAP API
fence_wti - Fence agent for WTI
fence_xcat - I/O Fencing agent for xcat environments
fence_xenapi - XenAPI based fencing for the Citrix XenServer virtual machines.
fence_zvm - I/O Fencing agent for GFS on s390 and zSeries VM clusters

We will use fence_ipmilan and fence_apc_snmp.

Configuring IPMI Fencing

Every fence agent has a possibly unique subset of options that can be used. You can see a brief description of these options with the pcs stonith describe fence_X command. Let's look at the options available for fence_ipmilan.

pcs stonith describe fence_ipmilan

Stonith options for: fence_ipmilan
  auth: IPMI Lan Auth type (md5, password, or none)
  ipaddr: IPMI Lan IP to talk to
  passwd: Password (if required) to control power on IPMI device
  passwd_script: Script to retrieve password (if required)
  lanplus: Use Lanplus
  login: Username/Login (if required) to control power on IPMI device
  action: Operation to perform. Valid operations: on, off, reboot, status, list, diag, monitor or metadata
  timeout: Timeout (sec) for IPMI operation
  cipher: Ciphersuite to use (same as ipmitool -C parameter)
  method: Method to fence (onoff or cycle)
  power_wait: Wait X seconds after on/off operation
  delay: Wait X seconds before fencing is started
  privlvl: Privilege level on IPMI device
  verbose: Verbose mode

One of the nice things about pcs is that it allows us to create a test file to prepare all our changes in. Then, when we're happy with the changes, merge them into the running cluster. So let's make a copy called stonith_cfg

pcs cluster cib stonith_cfg

Now add fencing.

#   temp file                     unique name    fence agent   target node                device addr           credentials
pcs -f stonith_cfg stonith create impi-an-c03n01 fence_ipmilan pcmk_host_list="an-m03n01" ipaddr=an-c03n01.ipmi login=admin passwd=admin op monitor interval=60s

 

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