ServiceGuard Serial HB config

[Jay Elkerton]

MC/ServiceGuard supports a two-node configuration using serial (RS232) communication line for a redundant heartbeat in addition to a heartbeat on a configured LAN. If you use a serial heartbeat configuration, the ServiceGuard team would like to know the reasons for using this configuration and the reasons for not using another configured LAN for the redundant heartbeat.

[Sridhar Bhaskarla]

Jay,

It is better to configure a network heartbeat than a serial heartbeat. This is because serial protocol do not have the capabilities that of TCP/IP with respect to the reliability.

So, if you have a chance to configure another heartbeat LAN, it's better to go for it.

-Sri

[Jay Elkerton]

Hi Sri,

I am a HP engineer working with the SG team (unfortunately this was not associated with my name). The question was posed to find out how and why customers configure a Serial HB.

My apologies for the confusion.

[Sridhar Bhaskarla · Accepted solution]

Yes I was confused with your message that why you wanted to use Serial Line while your SG team is suggesting for network heartbeat.

In my previous company we were using serial line because they were K580s and we didn't have enough network cards initially. Later we purchased GSC cards and got rid of serial heartbeat. That was only the reason I know why some people use serial heartbeat.

-Sri

[Sanjay_6]

Hi Jay,

Glad to know you are with the SG team of HP. I have not using serial heartbeat on any cluster i've configured till now. I have configured three clusters recently and am expecting another cluster configuration in a month or so. The hardware has already arrived. I've been using netowrk heartbeat only. Most of my systems are with two heartbeat network.

So i'm not using the serial heartbeat. Do you think there is any benefit of using serial heartbeat ?.

Regards
Sanjay

[John Bolene]

For machines only having one LAN card, the serial link would be needed.

I think most SG configs now require 2 LAN cards for redundancy in LAN anyway.

Possibly serial connection is not needed anymore?

[melvyn burnard]

As Jay will probably tell you, the serial link hbeat was designed for older systems with much less i/o card capability. With all the newer style systems, and expanded i/o, most people do not use the serial hbeat.
I think what Jay is asking of the forum is whether people DO see a need to keep it or not.
We now advise people NOT to use it if they can do multipole heartbeat lan's, as the serila heartbeat is NOT a full heartbeat.
Over to Jay ;-}

[Jay Elkerton]

As Melvyn indicated, my reason for asking about your use the Serial HB configuration was to begin to investigate whether customers still use and need this configuration since network card availablity seems less of a issue now.

Serial HB is supported but not "an advised" configuration. Discussion of these issues can be found in the following threads:

http://forums.itrc.hp.com/cm/QuestionAnswer/1,11866,0x96f8c6af36b7d5118ff10090279cd0f9,00.html

http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x04a6854994d9d4118fef0090279cd0f9,00.html

Jay