Veritas-bu

[Veritas-bu] Re: Ethernet port aggregation for performance

2006-03-31 13:37:21
Subject: [Veritas-bu] Re: Ethernet port aggregation for performance
From: ddunham AT taos DOT com (Darren Dunham)
Date: Fri, 31 Mar 2006 10:37:21 -0800 (PST)
> We attempted to do this where I work using Sun Trunking v1.3 in order 
> to increase the speed between our backup server and our data 
> warehouse, which holds over 4 TB of data.  Sun Trunking will only 
> work for increasing backup speeds if you are backing up multiple 
> servers simultaneously.  If you are trying to increase speed just to 
> back up one primary system, it will not work because all of the 
> options in Sun Trunking are still based on MAC address - one trunk 
> per MAC.  (Sun's engineers confirmed this for me.)  So, if you're 
> looking to increase the speed between one server and your backup 
> server, Sun Trunking will not do anything.

I'm not sure what you mean about all options being based on MAC.  Even
starting with 1.0, SunTrunking has included a round-robin policy. 
( policy=2 )  But for a backup server I don't think that's a big deal.
Because most of the traffic is incoming, it's the switch that is making
the important decisions, not the backup server.  So it would have to be
the switch that supports or doesn't support different link distribution
options.

Even with round-robin, I wouldn't expect single-stream TCP performance
to be incredibly increased.  But multi-stream performance should be
better.  I've seen some documents warn about increased out-of-order
packets occuring in this situation (because you're not forcing them to a
single path), but the last time I was doing something like this I found
round-robin to be the correct solution (it was direct attach multi-link
with no intervening switches).  

-- 
Darren Dunham                                           ddunham AT taos DOT com
Senior Technical Consultant         TAOS            http://www.taos.com/
Got some Dr Pepper?                           San Francisco, CA bay area
         < This line left intentionally blank to confuse you. >

<Prev in Thread] Current Thread [Next in Thread>