What happens if the servers you are using require ACPI=on in order to boot. For instance IBM X366 servers need ACPI set in order to boot. With ACPI=on both nodes reboot when a fence occurs(see "both nodes off problem" in thread below). This is not desirable, especially with active/active clusters. Thanks, dan > Sorry I didn't see this earlier! > > On Wed, 2006-08-02 at 15:50 +0000, danwest@xxxxxxxxxxx wrote: > > It seems like a significant problem to have fence_ipmilan issue a power-off followed by a power-on with a 2 node cluster. > > Generally, the chances of this occurring are very, very small, though > not impossible. > > However, it could very well be that IPMI hardware modules are slow > enough at processing requests that this could pose a problem. What > hardware has this happened on? Was ACPI disabled on boot in the host OS > (it should be; see below)? > > > > This seems to make a 2-node cluster with ipmi fencing pointless. > > I'm pretty sure that 'both-nodes-off problem' can only occur if all of > the following criteria are met: > > (a) while using a separate NICs for IPMI and cluster traffic (the > recommended configuration), > > (b) in the event of a network partition, such that both nodes can not > see each other but can see each other's IPMI port, and > > (c) if both nodes send their power-off packets at or near the exact same > time. > > The time window for (c) increases significantly (5+ seconds) if the > cluster nodes are enabling ACPI power events on boot. This is one of > the reasons why booting with acpi=off is required when using IPMI, iLO, > or other integrated power management solutions. > > If booting with acpi=off, does the problem persist? > > > It looks like fence_ipmilan needs to support sending a cycle instead of a poweroff than a poweron? > > The reason fence_ipmilan functions this way (off, status, on) is because > that we require a confirmation that the node has lost power. I am not > sure that it is possible to confirm the node has rebooted using IPMI. > > Arguably, it also might not be necessary to make such a confirmation in > this particular case. > > > According to fence_ipmilan.c it looks like cycle is not an option although it is an option for ipmitool. (ipmitool -H <ipaddr> -U <userid> -P <password> chassis power cycle) > > Looks like you're on the right track. > > -- Lon > > -- > Linux-cluster mailing list > Linux-cluster@xxxxxxxxxx > https://www.redhat.com/mailman/listinfo/linux-cluster -- Linux-cluster mailing list Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster
