How does one configure a fence device in the form of a NIC card in centos 5? Is the gnbd item relevant to this?
I have posted the question to linux-cluster also, but they are much less active overall, -so if you have info, massively appreciated...
-karl
Karl R. Balsmeier wrote:
How does one configure a fence device in the form of a NIC card in centos 5? Is the gnbd item relevant to this?
I'm not sure what 'a fence device in the form of a NIC card' is. the fence devices I'm familiar with include SCSI fence switches, fiberchannel SAN switches, and APC SmartPlug power switches.
in my test cluster, I used a Qlogic SANbox fiber switch to connect the cluster nodes to the shared storage. the fencing was done by sending the Qlogic the commands to enable/disable the ports of the two nodes so only the active node could access the shared storage.
I suppose an Ethernet analog in an ISCSI SAN environment would be to send commands to a layer-2 or layer-3 managed switch to manipulate the VLANs to disable the standby nodes from accessing the ISCSI target device. These systems would need separate dedicated NICs for LAN connectivity and cluster heartbeats.
John R Pierce wrote:
Karl R. Balsmeier wrote:
How does one configure a fence device in the form of a NIC card in centos 5? Is the gnbd item relevant to this?
I'm not sure what 'a fence device in the form of a NIC card' is. the fence devices I'm familiar with include SCSI fence switches, fiberchannel SAN switches, and APC SmartPlug power switches.
in my test cluster, I used a Qlogic SANbox fiber switch to connect the cluster nodes to the shared storage. the fencing was done by sending the Qlogic the commands to enable/disable the ports of the two nodes so only the active node could access the shared storage.
I suppose an Ethernet analog in an ISCSI SAN environment would be to send commands to a layer-2 or layer-3 managed switch to manipulate the VLANs to disable the standby nodes from accessing the ISCSI target device. These systems would need separate dedicated NICs for LAN connectivity and cluster heartbeats.
OK, so it sounds like I have enough ethernet devices, and your notes help me to understand the purpose and nature of fencing a lot more. I just need to isolate the potential on the iSCSI side of the equation as far as sending those signals to the managed switch.
Right now I run on extreme summit switches which should suffice, and broadcomm GBNICs.
The iSCSI device we are using is a PromiseRAID M300i or M500i.
It sounds on the surface like we might need a more solid fencing device... Anyone agree or disagree?
-karl
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John R Pierce -
Karl R. Balsmeier