AoE Windows Target

Zamar25 · Wed Jan 26, 2011 4:36 pm

Anyone can suggest AoE Target software (not hardware) that works on Windows? If there is no such software solution, will it be a big performance penalty to run Linux based AoE Target from inside VMWare Linux VM, running on Win7 host? Does it make sense to use AoE in that configuration - in what scenarios?

Wed Jan 26, 2011 9:34 pm

The only Windows AoE target I know is our own experimental kernel-mode AoE target. But we don't release it to public and don't have any plans to do it ever.

There's absolutely no sense in doing what you want (unless you have plenty of free time and just want to play with AoE).

Zamar25 wrote:Anyone can suggest AoE Target software (not hardware) that works on Windows? If there is no such software solution, will it be a big performance penalty to run Linux based AoE Target from inside VMWare Linux VM, running on Win7 host? Does it make sense to use AoE in that configuration - in what scenarios?

Zamar25 · Wed Jan 26, 2011 11:57 pm

Thanks! It sounds kind of strange though, since iSCSI imposes some processing overhead and other penalties. I do understand, Coraid controls hardware market due to limited demand, but why no-one is interested to offer such software for Windows to complement existing sales?

Thu Jan 27, 2011 8:13 am

1) With modern high GHz and multi-core CPUs, memory buses 5 years old supercomputers could only dream of, gigabytes of RAM and dedicated TCP and iSCSI offload silicon baked into even $20 "el cheapo" NIC PHY... All simplicity of AoE simply fades in darkness

And Ethernet frame size utilization, multi-packet completion, lack of advanced async processing questions with AoE raise. Also Windows network stack (unlike say Linux network stack) is not very good for raw Ethernet processing. In a nutshell: in Windows raw Ethernet is just another protocol, like TCP. And comes with all the complexity and re-buffering on receive (it does not happen with Linux). So at least for Windows there's no sense to use AoE. Except you want to save big bucks and buy dirt cheap per terrabyte CoRAID hardware.

2) B/c nobody wants to invest his time and money into the technology anybody controls on exclusive basis.

Zamar25 wrote:Thanks! It sounds kind of strange though, since iSCSI imposes some processing overhead and other penalties. I do understand, Coraid controls hardware market due to limited demand, but why no-one is interested to offer such software for Windows to complement existing sales?