I think I know the answer to this question based on all of the research I've done, but figured I'd ask anyway.
I needed a couple of servers for an HA cluster, and our "order" guy here ordered me a couple of Dell PowerEdge T110 II. I'd planned on using IPMI to fence these things with, but later found out that this model is only one of two PE servers Dell sells that has a stripped down BMC on it, and allows only local access. It's my fault for not looking closer at the specs, but I figured a PowerEdge server would have the stuff I needed.
So now I'm looking for a way to fence these without purchasing more equipment. I thought maybe IF-MIB, but I can't discover enough about that to determine whether that'll work for me.
I find it strange that using Conga (luci) from a third administration server I can reboot these two Dell nodes, and wonder why that works, how it's done, and why that wouldn't work as a fence method.
Any one dealt with this particular Dell PE and fencing in any form other than using something like an APC fence?
Thanks for any suggests. I've pretty much wore Google out, and I'm now in that round-robin mode of results where everything leads back to the same pages on different servers.
steve campbell
Greetings,
On Wed, Jan 9, 2013 at 1:08 AM, Steve Campbell campbell@cnpapers.comwrote:
Any one dealt with this particular Dell PE and fencing in any form other than using something like an APC fence?
IMHO, I am afraid that is the only choice you have.
Sorry for not having the replies, but I'd already turned on Digest mode for the list.
To Joseph and John:
Concerning the odd choice for a server. I don't usually pick the servers here since we sort of have a guy that does all of the ordering for us. He typically does a good job. I do scan the requirements for the machine before it's ordered. The problem here is that because this was a Dell "PowerEdge" I didn't bother looking to see what all was provided in the BMC stuff, so I can't blame anyone but myself. In this instance, "PowerEdge" is a real misleading label. And as I said, only two PEs of all their servers don't have the DRAC stuff on them.
To Patrick:
I had tried setting up BMC for using IPMI. Using ipmitools, I could only get stats on the local machine. I couldn't get remote stats.
The setup for the BMC, using Ctrl-E during boot, always stated that there was "No Active Lan" availailbe for BMC, and I couldn't figure out where that was turned on. I could set the address, indicate that the NIC was to be shared, all parameters were specified except being able to turn on a NIC for BMC. There's only one on-board NIC, so I wasn't picking the wrong one. After further reading about this particular model of PE, I began thinking that it just wasn't available remotely and only served to warn of failures by email.
If you can provide more on how you set this up, I'd like to compare my way against yours please, Patrick.
Anyway, thanks for the replies.
steve
On 1/8/2013 11:38 AM, Steve Campbell wrote:
Any one dealt with this particular Dell PE and fencing in any form other than using something like an APC fence?
what about fencing via your storage switch? thats the way I've setup several clusters. the standby server is warm and running, but has no access to the shared storage as its ports on the SAN switch are disabled. this can be done with ethernet or fiberchannel attached storage.
On 1/8/2013 6:20 PM, John R Pierce wrote:
On 1/8/2013 11:38 AM, Steve Campbell wrote:
Any one dealt with this particular Dell PE and fencing in any form other than using something like an APC fence?
what about fencing via your storage switch? thats the way I've setup several clusters. the standby server is warm and running, but has no access to the shared storage as its ports on the SAN switch are disabled. this can be done with ethernet or fiberchannel attached storage.
I won't have shared storage for these two servers. These servers will be firewalls, so IP's and a script to install the iptable rules will be all that float between the servers.
I started thinking about VMs, though. I'm not familiar with how the HA software works with virtual machines, but was wondering if putting the individual servers on separate hosts as VMs would provide me with fencing.
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
I won't have shared storage for these two servers. These servers will be
firewalls, so IP's and a script to install the iptable rules will be all that float between the servers. I started thinking about VMs, though. I'm not familiar with how the HA software works with virtual machines, but was wondering if putting the individual servers on separate hosts as VMs would provide me with fencing.
An odd choice of server for an HA environment wouldn't you say? That unit is nothing more than a desktop, it really doesn't have redundant anything...
Anyways, you can also use an snmp agent to down a switch port(s) that the server is attached to, I wrote one in the early 5.x days and it worked well. The cluster wiki had good docs. But that assumes you have a managed switch behind it.
jlc
On 1/9/2013 5:05 AM, Steve Campbell wrote:
I won't have shared storage for these two servers. These servers will be firewalls, so IP's and a script to install the iptable rules will be all that float between the servers.
how will you update the rules on the standby server if you're using power fencing?
and, I concur with the other response re: odd choice of hardware for HA. I would never use a system that doesn't have ECC memory for a mission critical application, and if its not mission critical, why bother with HA at all?
On 08.01.2013 20:38, Steve Campbell wrote:
I think I know the answer to this question based on all of the research I've done, but figured I'd ask anyway.
I needed a couple of servers for an HA cluster, and our "order" guy here ordered me a couple of Dell PowerEdge T110 II. I'd planned on using IPMI to fence these things with, but later found out that this model is only one of two PE servers Dell sells that has a stripped down BMC on it, and allows only local access. It's my fault for not looking closer at the specs, but I figured a PowerEdge server would have the stuff I needed.
So now I'm looking for a way to fence these without purchasing more equipment. I thought maybe IF-MIB, but I can't discover enough about that to determine whether that'll work for me.
I find it strange that using Conga (luci) from a third administration server I can reboot these two Dell nodes, and wonder why that works, how it's done, and why that wouldn't work as a fence method.
Any one dealt with this particular Dell PE and fencing in any form other than using something like an APC fence?
Thanks for any suggests. I've pretty much wore Google out, and I'm now in that round-robin mode of results where everything leads back to the same pages on different servers.
steve campbell
Hi,
in my test-lab I also have 2 Dell PE T110 II and one older T110. All 3 are a basic configuration (no iDrac express or enterprise). But they do have ipmi and are controllable and fencable via lan. These boxes just share ipmi with the onboard nic. Are you sure yours are only accessible locally? And if you have local ipmi I see no reason why external should not work.
Regards Patrick
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John R Pierce -
Joseph L. Casale -
Patrick Hurrelmann -
Rajagopal Swaminathan -
Steve Campbell