Skip to navigation

Warning message

log in to add comments or rate this document

Fence Device and Agent Information for Red Hat Enterprise Linux

Updated 2013-02-01T16:24:00+00:00

Overview

Fencing is the disconnection of a node from shared storage. Fencing cuts off I/O from shared storage, thus ensuring data integrity. A fence device is a hardware device that can be used to cut a node off from shared storage. This can be accomplished in a variety of ways: powering off the node via a remote power switch, disabling a Fibre Channel switch port, or revoking a host's SCSI 3 reservations. A fence agent is a software program that connects to a fence device in order to ask the fence device to cut off access to a node's shared storage (via powering off the node or removing access to the shared storage by other means).

This article outlines many commercial fence devices and maps them to the  fence agents that support them. Where available, information on  specific firmware revisions is provided.

For more detailed information on fencing and fence devices, see the official product documentation:

NOTE:

  • This is a comprehensive list of devices. Not all of these devices are supported in Red Hat Enterprise Linux or Red Hat Enterprise Virtualization. Refer to Fence Support Matrix for Red Hat Enterprise Linux High Availability/Clustering and Red Hat Enterprise Virtualization to determine if a particular fence agent is supported on your product.
  • Every SNMP fence agent has support for SNMP v1/2c/3.
  • N/A in "Supports List Action" indicates that this device can only access one machine and is not capable of listing multiple outlets.
  • Not every IPMI-capable device is listed here. Generally, if your device supports IPMI v1.5+ and IPMI over LAN, fence_ipmilan is supported for that device.
  • Any device that has "yes" in the IPMI v1.5+ Support column can be used with the fence_ipmilan agent. In general, it is preferred to use the ipmilan agent on devices that properly implement IPMI. However, in some cases this is not possible due to incomplete implementations, firmware bugs, or blade chassis devices that require a slot/port parameter. In the cases where fence_ipmilan cannot be used, the native fence agent can be used instead.

Support Status

NOTE: This article does not comment on the supportability of the software fence agents that are shipped with Red Hat Enterprise Linux and Red Hat Enterprise Virtualization. It does list which specific hardware fence devices are supported for a given software fence agent. In order to determine if a particular hardware fence device is supported, first determine if the fence agent corresponding to that device is supported in the version of Red Hat Enterprise Linux or Red Hat Enterprise Virtualization that you are using via the information at Fence Support Matrix for Red Hat Enterprise Linux High Availability/Clustering and Red Hat Enterprise Virtualization. If the fence agent corresponding to your device is supported, then check to see if your specific model is supported via the below tables. The below tables contain hardware devices that might be either unsupported or in Technology Preview status. Check with the Fence Support Matrix article to determine if your fence agent (and therefore fence device) is supported.

Fence Device and Agent Matrix

Vendor /

Fence Device

Fence

Agent

Fence Type Style

Connection

Methods

Supports

List

Action

Tested On:

Hardware /

Firmware

SNMP

Support

IPMI

v1.5+

Support

Notes

IPMI v1.5+ Compliant Devices

over LAN

ipmilan Power C + ipmitool ipmi N/A no yes [1]
Virtualization (libvirt) xvm Virt Guest C (client/server app)

custom protocol

using multicast and

libvirt remote connections

no no no
Virtualization (libvirt) virt Virt Guest C (client/server app)

custom protocol using either

multicast or serial vmchannel and

QMF/libvirt

no no no
Virtualization (libvirt) virsh Virt Guest python libvirt remove connections no no no
Virtualization (RHEVM) rhevm Virt Guest python RHEVM REST API no no no [2]
Virtualization (VMware) vmware Virt Guest

python + fencing lib + VMware utils +

PerlVI based helper

Running vmrun/helper yes no no [3]

Virtualization

(VMware)

vmware_soap Virt Guest python + fencing lib + python-suds SOAP API yes no no [4]
SCSI 3 Persistent Reservations scsi LUN access perl + sg3_utils ioctls N/A no no [5]
General IF:MIB ifmib Network Port python + SNMP fencing lib snmp yes yes no
APC apc

External

Power

Switch

python + fencing lib ssh + telnet yes AP7951 & AOS v2.7.0 yes no [6] [15]
APC apc

External

Power

Switch

python + fencing lib ssh + telnet yes AP7941 & AOS v3.5.7 yes no [15]
APC apc

External

Power

Switch

python + fencing lib ssh + telnet yes AP9606 & AOS v2.5.4 yes no [15]
APC apc_snmp

External

Power

Switch

python + SNMP fencing lib snmp yes yes no [15]
Baytech / RPC baytech

External

Power Switch

perl telnet (ssh, kermit possible) no

RPC27-20nc +

Cyclades TS

yes no
Blade Technologies / Rackswitch rackswitch

External

Power Switch

C telnet-like no
Brocade brocade Fibre Channel Port perl telnet no yes no
Bull / NovaScale bullpap Power

perl

PAP console (using

vendor tools)

no yes no
Cisco MDS cisco_mds Network Port python + SNMP fencing lib snmp yes yes no [7]
Cisco UCS cisco_ucs Power python + fencing lib http yes no yes [8]
Dell / DRAC 3 & DRAC/MC drac Power perl telnet no DRAC/MC & v1.1, v1.2, v1.3 read-only no (some models)
Dell / DRAC 4 drac Power perl telnet no DRAC 4/I & v1.0, v1.40 yes no (some models)
Dell / DRAC 5 / CMC drac5 Power python + fencing lib ssh + telnet N/A DRAC 5 & v1.0, v1.21 yes yes
Dell / iDRAC (DRAC 6) ipmilan Power C + ipmitool ipmi no no yes [9]
Egenera egenera Power perl ssh no yes no
ePowerSwitch eps Power python + fencing lib http yes ePowerSwitch 8M+ & v1.0.0.4 some models
Fujitsu / RSB rsb Power python + telnet lib telnet no yes no (some models)
HP / iLO, iLO2 ilo Power python + fencing lib https (-z added always) N/A iLO & 1.91, iLO2 & 1.22, 1.50 yes yes [10]
HP / iLO MP ilo_mp Power python + fencing lib ssh + telnet N/A iLO2 MP yes yes
HP / iLO3, iLO4 ipmilan Power C + ipmitool ipmi no no yes

[11]

IBM / BladeCenter bladecenter Power python + fencing lib ssh + telnet yes firmware BRET58K rev 16 yes no
IBM / BladeCenter ibm_blade Power python + SNMP fencing lib snmp yes yes no
IBM / LPAR lpar Power python + fencing lib ssh + telnet yes HMC v3, HMC v4 no no
IBM / RSA rsa Power python + fencing lib ssh + telnet N/A yes yes
Intel / Modular Server System intelmodular Power python + SNMP fencing lib snmp yes MFSYS25 & v2.6 yes yes [12]
Intel / IMM ipmilan Power C + ipmitool ipmi no no yes
McDATA mcdata

Fibre

Channel Port

perl telnet no

firmware

v01.03.00

v02.00.00

v04.01.00

yes no
QLogic / SANbox sanbox2

Fibre

Channel Port

python + fencing lib ssh + telnet yes yes no
Sun / ILOM ipmilan Power C + ipmitool ipmi no no yes
Vixel (Emulex) vixel

Fibre

Channel Port

perl telnet no yes
WTI Remote Reboot PDUs wti

External

Power

Switch

python + fencing lib ssh + telnet yes

RSM-8R4, MPC-8H, IPS series, VMR-8,

NPS series

yes no [13]
WTI Serial Power Control Devices rps10 External Power Switch C serial RS232 no RPS-10HD no no [14]

Notes:
1. ipmitool works with IPMI v1.5 and v2.0+
2. RHEL 5.7+, RHEL 6.2+.  Red Hat Enterprise Virtualization 3 or later.
3. fence_vmware is not supported. It was superseded by fence_vmware_soap. See [4].
4. RHEL 5.7+, RHEL 6.2+.  VMware vSphere ESX 4.1.  Version 5.0 requires a VMware workaround.
5. Fibre Channel or iSCSI SAN storage: SAN device must be SCSI3 Persistent Reservation Compliant with support for preempt-and-abort command. See this article for more information.
6. SSH has to be set to protocol 1 and des/blowfish cipher different menu for admin/user (valid for every APC)
7. Cisco MDS 9124 & 9134 (RHEL 5.4+)
8. The Cisco UCS blades do support ipmi-based fencing, but this requires connecting to each blade individually. The Cisco UCS-based fence agent allows fencing to be done by connecting to the UCS chassis and specifying the blade by name.
9. ipmi over LAN support may be disabled by default on iDRAC/DRAC6 hardware. Follow the manufacturer's instructions for enabling ipmi over LAN support so that the fence_ipmilan agent will work.
10. fence_ipmilan can also be used with iLO2 version 2.00 and later.
11. fence_ipmilan must be used with the -P option to enable Lanplus. It also requires usage of the -T parameter to provide at least a 4 second timeout rather than the default fence_ipmilan default of 2 seconds. The -T parameter is provided in versions of fence_ipmilan from Red Hat Enterprise Linux 5.5.z and up.
12. According to the manual, SNMP access is read-only, but it is in fact read-write. IPMI v2 compatible.
13. When using SSH, sometimes it is necessary to set login_timeout to 10. NPS models are supported with RHEL 5.7, 6.1, and later.
14. Two-node clusters only.
15. Newer revisions of APC switched rack PDUs, particularly those with AOS version 5.0 or later., are not known to work well with fence_apc. Please use fence_apc_snmp instead. The AOS version can be seen immediately after logging in.

Supported External Fence Device Models

Manufacturer Model
APC Switched Rack PDU AP7902, AP7902J
APC Switched Rack PDU AP7930, AP7998
APC Switched Rack PDU AP7900
APC Switched Rack PDU AP7901
APC Switched Rack PDU AP7911, AP7911A
APC Switched Rack PDU AP7920
APC Switched Rack PDU AP7921
APC Switched Rack PDU AP8941 (using SNMP)
WTI IPS-15
WTI IPS-1600
WTI IPS-1600-CE
WTI IPS-400
WTI IPS-400-CE
WTI IPS-800
WTI IPS-800-CE
WTI MPC-8H (5.3)
WTI NBB-1600
WTI NBB-1600-CE
WTI RPS-10 Series (Note: Two-node clusters only)
WTI RSM-8R4
WTI TPS-2
WTI NPS Series
WTI

VMR Series

Supported SAN-Based Fence Device Models

Manufacturer Model
Brocade Silkworm 2400
Brocade Silkworm 2800
Brocade Silkworm 3200
Brocade 200E
Brocade 300
Brocade 4100
Brocade 4900
Brocade 5100
Brocade 5480
Dell PowerVault 56F
McData Sphereon 4500
Vixel 9200