Hacmp

UNIX AIX
1

Hi,

I have question about HA. I have 2 node cluster (node A and node B). I have configured network and disk HB. If my network is up and i remove both the fc cables from node A will my cluster failover to node B? I have checked and its not working, if i want my cluster to failover in this scenario then what changes needs to be done.

2

Hello,

I just posted few days ago and this is exactly the same problem:
PowerHA(HACMP) full vg loss - cluster hangs on release_vg_fs event
and I was unable to find solution yet.

Vilius M.

3

PowerAIX are you also using the same version like Vilius
AIX 6.1 TL7 SP6
POwerHA 6.1 SP10

please confirm

4

oslevel 6.1 TL 7 and hacmp 6.1.0

5

Check my post conclusion I pointed above.

6

Little time - so I shall be quick.

What PowerHA/HACMP (now System Mirror) monitors - traditionally - is the topology - for failures - and based on what has happened, it makes modifications.

1) Disks are a resource, not topology
2) diskhb network is a NON-IP network, so application service is not dependent on that.
3) HACMP does not respond - out of the box - to resource failures. You need to setup an application and/or event notification to respond to that.

Suppose, rather than both fc - you had said both/all ethernet (i.e., IP connectivity) - the result would be the same - HACMP does not move the resource group. This is because HACMP can see both nodes are operational - but NO nodes (there are only two!) can communicate with other. When no nodes can communicate via IP network HACMP concludes a "Global" network failure, and since no nodes can communicate - it does not matter where the application/service is at - no clients could communicate - so nothing is moved.

The short of it - you need to configure an application monitor that "decides", whether to move or not. A simple way to force a move (one that would work "out of the box" is a so-called panic halt (halt -q). Not really recommended of course, but it does, in an educational/test phase help demonstrate what events HACMP responds to, and what events it does not respond to.

Hope this helps.