lan failure simulation

[christian_2]

Hi guys,

I'm doing lan link tests and I got an unexpect result. When I disconected all cables from one
machine, the other, that has all cables conected rebooted and the one that has no cables got the lock and still active. the
command cmviewcl show that lan interfaces wasnt
down.

Have someone pass throught this problem ?
Now, I'm just using core-io lan, HP-UX 11 and
MCSG 11.07

thanks in advace!

[BFA6]

Hi,

Have you checked syslog.log for error messages from cmcld ?

Hilary

[Paula J Frazer-Campbell]

Christian

I do not run service guard but it looks like a heartbeat setting or a patch related to heartbeat.

Paula

[BFA6]

Christian,

Another thought.
If node A is running package & has cluster lock disk, and you pull lan cables from A (both data & heartbeat), both machines will think the other has died & race for the cluster lock disk. A already has it, B won't get the lock disk, so will TOC.

Hilary

[David Navarro]

Hi, this sounds like a patch problem. Be sure you have installed last patches for SG and LAN, etc..

David.

[David Navarro]

Hi, again, I have read Hilary answer,and I agree with their opinion. If you disconnect all cables, communications betwen nodes are lossed, then cluster must be reformed, then first machine that get cluster lock. will form the new cluster.

A good test, can be disconnect just one network cable, look if traffic and addresses are conmuted to the other one. Then disconnect this other, I think package will be transferred to alternate node in this situation.

David.

[Bill McNAMARA_1]

thats normal.. service guard check this..

rather than ifconfig lan down
use lanadmin to reset the lan.
That should simulate it.

Or pull cable or wet the card!
I prefer lanadmin!

Later,
Bill

[melvyn burnard]

What you are seeing is normal behaviour, based on the fact that you have Multiple Points of failure.
As previously said, if the node that stayed up already had access to the cluster lock disc, because ALL communiactions were lost, that node managed to grab the cluster lock diosc BEFORE the other node, and hence stayed up, forcing the other node to TOC.

You should definitely check you ar patched to the lates possible level, bearing in mind that SG patches are NOT included in the Patch Bundle CD's!

[Sanjay_6]

Hi,

Take a look at this thread from the SG FAQ, which tries to explain the scenario you are having,

http://docs.hp.com/hpux/onlinedocs/ha/haFAQindex2.html#All%20Networks%20fail,%20which%20node%20wins?

Here is the FAQ,

http://docs.hp.com/hpux/onlinedocs/ha/haFAQindex2.html

Hope this helps.

Regds

[christian_2]

thank you guys, but this
is not an correct behave.
there was a GOOD node on
cluster and this should
be up, get the lock and
take the ownership of
all packages running on node
that has all cables disconected. this one, that
have cables disconect should not get the lock because his
networks were down. if someone
have tested this on both nodes, please notify me

thanks again