APA Vs MCSG

[vtpaulson]

Guys I am implementng a MCSG cluster in L class server. Each server with 4 1000GB lan cards with APA software.

Now the question is can I use just APA software to take care of my lan card adapters failure (That way I can make use of all lan cards) or is it a right solution to use the network failover through MCSG??

Also whats the max. bandwidth I can get practically in 4 GB lan cards??

Thanks

Paulson

[Berlene Herren]

APA and MC/SG Version A.11.09 or later support:
all PCI and HSC 100Base-TX cards on all platforms that the cards support except the T-Class.
all PCI and HSC 1000Base-SX cards on all platforms that the cards support except the A-Class. 1000Base-TX is not supported at this time.
HP-PB card on all platforms that it supports.

I think this document will answer your questions.

http://www.docs.hp.com/hpux/onlinedocs/netcom/apa_final.pdf

regards,
berlene

[melvyn burnard]

Theoretically, tunneling 4 1gB cards together with APA should give you 4Gb throughput, with the load balancing across the 4 cards. As and if a card "fails", the others should accept the load. This can be used without ServiceGuard to give you some of the network failure protetcion of SG.

However, if you are using SG< you can still use APA, but he better way to utilise APA within SG is to have 2 Gbit cards using APA as the Primary lan, and the other 2 Gbit cards using APA as the standby lan.,

In this way, you get double the speed of a single gbit card, with the redundancy of APA, and then on top of that you get the Network failover facility of SG.

Hope that helps you.

[vtpaulson]

Guys thanks for your replies.

But if I use MCSG to failover my card then I will be wasting 2 cards as it will be used only when primary lan fails. Where as if I use APA then I can make use of all 4 1GB lan cards also it will take care of the card failure right? Ofcourse I am using MCSG to take care of my server failure. What you guys think about this solution?.

Also if I use APA over 4 1GB lan cards I doubt I can even get 2Gb practically due to the TCP/IP limitations. I need the clarification here.

[Carsten Krege · Accepted solution]

If you have 4 separate lan interfaces configured to one APA trunk it is not necessary to configure a standby lan. In case of a failure of one lan interface you will still have 75% of your bandwith accessible. Your proposed SG setup is fine.

Configuring a standby lan for an APA trunk makes only sense if you are using mulitport lan interfaces where you put all ports on one card into the trunk. If you wouldn't configure a standby lan, you would be unprotected in case of a failure of the lan interface.

Since you plan to use 4 separate cards your config is not prone to this scenario.

According performance: I'm not an expert but I have heard that APA adds only very few overhead, so that an performance decrease of only a few(!) percents can be expected when using APA.

Carsten

[vtpaulson]

Hi Carsten,

Thanks for your reply. This is what exactly I was looking for...