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Chapter 4. Fence Devices

This chapter documents the fence devices currently supported in Red Hat Enterprise Linux High-Availability Add-On.
Table 4.1, “Fence Device Summary” lists the fence devices, the fence device agents associated with the fence devices, and provides a reference to the table documenting the parameters for the fence devices.
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Table 4.1. Fence Device Summary
Fence Device Fence Agent Reference to Parameter Description
APC Power Switch (telnet/SSH) fence_apc Table 4.2, “APC Power Switch (telnet/SSH)”
APC Power Switch over SNMP fence_apc_snmp Table 4.3, “APC Power Switch over SNMP”
Brocade Fabric Switch fence_brocade Table 4.4, “Brocade Fabric Switch”
Cisco MDS fence_cisco_mds Table 4.5, “Cisco MDS”
Cisco UCS fence_cisco_ucs Table 4.6, “Cisco UCS”
Dell DRAC 5 fence_drac5 Table 4.7, “Dell DRAC 5”
Dell iDRAC fence_idrac Table 4.25, “IPMI (Intelligent Platform Management Interface) LAN, Dell iDrac, IBM Integrated Management Module, HPiLO3, HPiLO4”
Eaton Network Power Switch (SNMP Interface) fence_eaton_snmp Table 4.8, “Eaton Network Power Controller (SNMP Interface) (Red Hat Enterprise Linux 6.4 and later)”
Egenera BladeFrame fence_egenera Table 4.9, “Egenera BladeFrame”
Emerson Network Power Switch (SNMP Interface) fence_emerson Table 4.10, “Emerson Network Power Switch (SNMP interface) (Red Hat Enterprise Linux 6.7 and later)”
ePowerSwitch fence_eps Table 4.11, “ePowerSwitch”
Fence virt (Serial/VMChannel Mode) fence_virt Table 4.12, “Fence virt (Serial/VMChannel Mode)”
Fence virt (fence_xvm/Multicast Mode) fence_xvm Table 4.13, “Fence virt (Multicast Mode) ”
Fujitsu Siemens Remoteview Service Board (RSB) fence_rsb Table 4.14, “Fujitsu Siemens Remoteview Service Board (RSB)”
HP BladeSystem fence_hpblade Table 4.15, “HP BladeSystem (Red Hat Enterprise Linux 6.4 and later)”
HP iLO Device fence_ilo Table 4.16, “HP iLO (Integrated Lights Out) and HP iLO2”
HP iLO over SSH Device fence_ilo3_ssh Table 4.17, “HP iLO over SSH, HP iLO3 over SSH, HPiLO4 over SSH (Red Hat Enterprise Linux 6.7 and later)”
HP iLO4 Device fence_ilo4 Table 4.25, “IPMI (Intelligent Platform Management Interface) LAN, Dell iDrac, IBM Integrated Management Module, HPiLO3, HPiLO4”
HP iLO4 over SSH Device fence_ilo4_ssh Table 4.17, “HP iLO over SSH, HP iLO3 over SSH, HPiLO4 over SSH (Red Hat Enterprise Linux 6.7 and later)”
HP iLO MP fence_ilo_mp Table 4.18, “HP iLO (Integrated Lights Out) MP”
HP Moonshot iLO fence_ilo_moonshot Table 4.19, “HP Moonshot iLO (Red Hat Enterprise Linux 6.7 and later)”
IBM BladeCenter fence_bladecenter Table 4.20, “IBM BladeCenter”
IBM BladeCenter SNMP fence_ibmblade Table 4.21, “IBM BladeCenter SNMP”
IBM Integrated Management Module fence_imm Table 4.25, “IPMI (Intelligent Platform Management Interface) LAN, Dell iDrac, IBM Integrated Management Module, HPiLO3, HPiLO4”
IBM iPDU fence_ipdu Table 4.22, “IBM iPDU (Red Hat Enterprise Linux 6.4 and later)”
IF MIB fence_ifmib Table 4.23, “IF MIB”
Intel Modular fence_intelmodular Table 4.24, “Intel Modular”
IPMI (Intelligent Platform Management Interface) Lan fence_ipmilan Table 4.25, “IPMI (Intelligent Platform Management Interface) LAN, Dell iDrac, IBM Integrated Management Module, HPiLO3, HPiLO4”
Fence kdump fence_kdump Table 4.26, “Fence kdump”
Multipath Persistent Reservation Fencing fence_mpath Table 4.27, “Multipath Persistent Reservation Fencing (Red Hat Enterprise Linux 6.7 and later)”
RHEV-M fencing fence_rhevm Table 4.28, “RHEV-M REST API (RHEL 6.2 and later against RHEV 3.0 and later)”
SCSI Fencing fence_scsi Table 4.29, “SCSI Reservation Fencing”
VMware Fencing (SOAP Interface) fence_vmware_soap Table 4.30, “VMware Fencing (SOAP Interface) (Red Hat Enterprise Linux 6.2 and later)”
WTI Power Switch fence_wti Table 4.31, “WTI Power Switch”

4.1. APC Power Switch over Telnet and SSH
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Table 4.2, “APC Power Switch (telnet/SSH)” lists the fence device parameters used by fence_apc, the fence agent for APC over telnet/SSH.
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Table 4.2. APC Power Switch (telnet/SSH)
luci Field cluster.conf Attribute Description
Name name A name for the APC device connected to the cluster into which the fence daemon logs by means of telnet/ssh.
IP Address or Hostname ipaddr The IP address or host name assigned to the device.
IP Port (optional) ipport The TCP port to use to connect to the device. The default port is 23, or 22 if Use SSH is selected.
Login login The login name used to access the device.
Password passwd The password used to authenticate the connection to the device.
Password Script (optional) passwd_script The script that supplies a password for access to the fence device. Using this supersedes the Password parameter.
Power Wait (seconds) power_wait Number of seconds to wait after issuing a power off or power on command.
Power Timeout (seconds) power_timeout Number of seconds to continue testing for a status change after issuing a power off or power on command. The default value is 20.
Shell Timeout (seconds) shell_timeout Number of seconds to wait for a command prompt after issuing a command. The default value is 3.
Login Timeout (seconds) login_timeout Number of seconds to wait for a command prompt after login. The default value is 5.
Times to Retry Power On Operation retry_on Number of attempts to retry a power on operation. The default value is 1.
Port port The port.
Switch (optional) switch The switch number for the APC switch that connects to the node when you have multiple daisy-chained switches.
Delay (optional) delay The number of seconds to wait before fencing is started. The default value is 0.
Use SSH secure Indicates that system will use SSH to access the device. When using SSH, you must specify either a password, a password script, or an identity file.
SSH Options ssh_options SSH options to use. The default value is -1 -c blowfish.
Path to SSH Identity File identity_file The identity file for SSH.
Figure 4.1, “APC Power Switch” shows the configuration screen for adding an APC Power Switch fence device.
APC Power Switch
View larger image
APC Power Switch

Figure 4.1. APC Power Switch

The following command creates a fence device instance for a APC device: 
ccs -f cluster.conf --addfencedev apc agent=fence_apc ipaddr=192.168.0.1 login=root passwd=password123
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The following is the cluster.conf entry for the fence_apc device: 
 <fencedevices>
   <fencedevice agent="fence_apc" name="apc" ipaddr="apc-telnet.example.com" login="root" passwd="password123"/>
 </fencedevices>
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