Change in cluster ascii file - can it be online ?

[Ganesan R]

Hi All,

I have a task on service guard. I have one LAN interface configured on cluster nodes which will be used only for backup. It is configured as stationary IP in the cluster ascii file. But no package using this subnet, so no package ip bound to this interface.

NETWORK_INTERFACE lan0
STATIONARY_IP 10.0.68.30

This backup interface is 10/100. Now we are going to install Gigabit ethernet card and use it for backup instead of old 10/100 card.

So after putting the Gigabit card, remove the ip from lan0 and assign to Gigabit card. From cluster perspective, lan device file(lan0) has to be changed with new gigabit device and has to applied in the cluster. My question is,

Can this cluster changes be done online without halting the cluster? Means take the running cluster ascii file, modify it, then cmcheckconf and cmapplyconf.

[Steven E. Protter]

Shalom,

You make your changes to the text configuration file.

You run cmcheckconf then cmapplyconf to modify the cluster.

You do not have to halt the cluster to do this work. You need to do it one node at a time.

You should make sure all packages will actually run on one node without overloading it or crashing the package.

SEP

[Duncan Edmonstone · Accepted solution]

What version of Serviceguard?

< 11.18 = no you will need to stop your cluster.
>= 11.18 = you can probably make the change online - see this section in the manual:

http://docs.hp.com/en/B3936-90140/ch07s04.html#cegedaci

HTH

Duncan

[Ganesan R]

Hi,

Thanks for your replies. My SG version is 11.16

Duncan,

http://docs.hp.com/en/B3936-90140/ch07s04.html#cegedaci

is the above link specific to >= 11.18 ?

[Duncan Edmonstone]

Yes that link was for >=11.18 only.

Here's the equivalent link for the 11.16 manual:

http://docs.hp.com/en/B3936-90079/ch07s04.html#ciibdgcg

As you will see, no mention of being able to change network parms online.

HTH

Duncan

[Mel Burslan]

From my personal experience, on version 11.16, cmapplyconf requires your cluster to be down. Editing the ascii file is not a problem of course while the cluster is running. I never done this but theoretically, cmcheckconf can also be run while the cluster is up. But cmapplyconf needs the cluster down. Sorry for being the bearer of the bad news.

[Steven E. Protter]

Sorry to disagree, but I just did a cmcheckconf and cmapplyconf on a 11.16 SG cluster in my home(Yes I know I'm a nut case). I was just polishing up my SG skill, but my package and floating IP address stayed on line.

One node at a time.

SEP

[Duncan Edmonstone]

SEP,

You can certainly cmapplyconf while a cluster is up (e.g. after adding a cluster node), but I'm pretty sure you *can't* change a NIC definition while the cluster is up on versions below 11.18. Of course I don't have a multi-node test cluster on a version below 11.18 to try this on, so I guess I could be wrong... what did you actually change?

Where are Stephen D/Melvyn B to settle this disagreement?

HTH

Duncan

[Vishu]

Hi Ganesan,

I agree to Duncan that changing a LAN definition in cluster config requires that cluster to be down. till cmcheckconf you can done online, but cmapplyconf need cluster to be halted.


Thanks

[melvyn burnard]

The main question here is, will the new card go in the same slot as the exisiting one?
and will it use the same driver?

I ask because if you replace the exisiting card (due to a failure) with an equivalent card, you CAN cmapplyconf to update the MAC address in the binary in A.11.16, but if the driver is not the same, you first need to get the driver associated with that new card, and unless you are on Hp-UX 11.31, that is a reboot.
If you are changing the card hardware location, then this can only be done online with A.11.18 and greater versions of Serviceguard

[Steven E. Protter]

That resolves it.

So I can and did change my SG cluster with cmapplyconf. What I did not do specifically was switch out LAN configuration as my systems only have 3 ports and one of the built ins is dead, as its a D class server.

SEP