xntpd starts after reboot only when HACMP services are started ?

UNIX AIX
1

Hello,

Running AIX 6.1, AIX machine is HACMP node.
Recently I set up ntp service. Started xntpd by hand - everythig is OK. Configured xntpd to start after reboot and rebooted the machine. After reboot checked xntpd:

# lssrc -a|grep ntp
xntpd            tcpip                         inoperative

I didn't find any reason why it didn't start. Anyway I started HACMP after some time - and xntpd started right away:

# lssrc -a|grep ntp
 xntpd            tcpip            458684       active

So after some checks it was obvious - xntpd starts automatically only after cluster services are started.

Why this is happening ?

thanks
Vilius

2

Depending on the cluster setup there is no IP address active after node boot that could be used by xntpd. Service IP labels are active only after a Resource Group came online and so are the corresponding routes. Make xntpd use the node�s Persistent Address.

3

Hi,

I tried to start xntpd when hacmp is down(only host address is active) but results are the same. By the way xntpd starts not after bringing up the resourse group(resource group brings service IP up), but only after hacmp services start(starting hacmp services doesn't activate resource groups automatically in this configuration).
What do you mean by this:

How do I make xntpd to use one IP or another ?

V

4

what HACMP/PowerHA version do you use?

5

I think it's HACMP 5.4

V

6

You did not tell us what your cluster's topology looks like and you think the HA release is 5.4. So let me make some assumptions based on what it should look like when you use IPAT with aliasing which is the default for 5.4.

Your cluster has two physical adapters which are configured during boot with a non routed IP address each. E.g. after node boot your adapters are configured with sth. like 192.168.10.1 and 192.168.20.1 on one node and 192.168.10.2 and 192.168.20.2 on the other. These addresses are just used for cluster communication and the nodes are not reachable via TCP/IP from your production network. Only after a Resource Group is online you have a (Service Label) IP address active and the default route. At least this is the presuppostion HA makes. If you understand this you now know why xntpd becomes active after a RG came online only: HA 5.4 deferrs the start of all services that rely on a working production network.

To avoid the nodes (without an active RG) being not reachable via TCP/IP from production network IBM introduced the Persistent Address. Such an address is configured during node boot as an alias and while it is accessible right from the start it is not part of a resource group. Opposed to an aliased boot address such a Persistent IP may be in the same subnet as the Service IP Label. Because the default route is usually tied to this subnet the node is then always reachable just as any other non-clustered node. With a working TCP/IP environment you could start it from the /etc/rc.tcpip automatically with

start /usr/sbin/xntpd "$src_running"

and/or manually with

# startsrc -s xntpd

You may read the HA 5.4 Installation Guide and the HA 5.4 Admin Guide. Then follow up with the sg246769 redbook aka HACMP cookbook.