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Date:      Wed, 2 Mar 2011 09:26:26 -0500
From:      David <>
To:        Robert Bonomi <>
Cc:, David <>
Subject:   Re: FreeBSD Performance
Message-ID:  <>
In-Reply-To: <>
References:  <>

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On Feb 27, 2011, at 4:43 PM, Robert Bonomi wrote:

>> =46rom  Sun Feb 27 14:54:09 2011
>> From: David <>
>> Date: Sun, 27 Feb 2011 15:46:03 -0500
>> To:
>> Subject: FreeBSD Performance
>> Hello All:
>> I am curious... does anyone know of a reasonably priced commodity =
>> capable of sourcing/sinking 10 Gbps of data from/to disk via 2 x 10 =
>> network interfaces? Any ideas on how hard this would be to do with=20
>> FreeBSD?
>> I know of a proprietary linux-based system, but looking for =
>> FreeBSD based system.

Thanks for the comments Robert...

> A lot depends on what you need to do with the data.

At the moment, I'm just looking to see if anyone has tried anything =
I have a detailed set of requirements/results, but wanted to keep things =
simple initially.
For now, let's just say there are two use cases:

1. Record 10 Gbps of data received from 2 10xGE cards onto hard disk =
2. Playback 10 Gbps of data out over 2 10xGE cards onto network.

>  Do you need just the 'contents' of the network packets -- i.e. are =
>  trying to send/recieve a single stream of data -- or do you need=20
>  complete headers, augmented with timestamps, such that you can re-
>  construct/replay what was 'seen on the wire'?

Just contents is fine.

>  Is the box 'dedicated' to receiving (or sending), and does =
>  while that operation is in process? or do you need to sample the data =
>  real-time as well?


>  Another question is _how_long_ you need to handle the 2x10gbit/sec of=20=

>  data. a few seconds? a few tens of seconds?  minutes? hours?

One hour (for now).

>  If you need to 'go to disk' in real-time, you're looking at needing
>  at least 3-4 gigabyte/sec of bandwith to disk.  No commodity drives=20=

>  provide that kind of capacity, so you're looking at multiple drives=20=

>  'in parallel' -- the logical equivalent of a 'striped' RAID array. =20=

>  Probably 12-16 spindles paralleled.  Best handled with _hardware_=20
>  raid, directly in the disk controller, but I don't know of a =


>  controller that supports enough spindles to give that bandwidth.
>  This means one is best off doing it in the application softwre =
>  rather than trusting the O/S to get it right.


>   You're also looking at a _big_ disk array. Around 200 gigs for ONE=20=

>  MINUTE of data.  Need 'only' an hour?  That's merely 12 terabytes.

Yes :)

> The O/S is -relatively- unimportant. <wry grin>

OK. As a recent convert to FreeBSD, I was hoping you would tell me=20
that the clean architecture and efficient implementation of FreeBSD =
would solve
all of my problems :)

> You need _good_ network cards, with good drivers -- preferably ones =
> most of the network stack can be off-loaded onto the card itself.

Yes. Something like TOE, batched interrupts, etc.

> You also need good disk controllers, ideally semi-autonomous (like =
> with fairly large data buffers.


OK. Thanks for the comments, that is helpful. I would be very interested
to hear if anyone has had experience implementing a system like
this (or close to it). I'm trying to decide whether I should try this =
or proceed with the current linux-based system.

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