Re: Soft-Raid 0 Performance | Transfer two Data-Streams (CPU+FPGA) to the same Soft-Raid

[Coly Li <colyli@suse.de>]

On 2017/1/17 下午11:00, Eric Schwarz wrote:
> Hello mailing list,
> 
> I have got two questions:
> 
> 1.) I have set-up a softraid (raid level 0) with mdadm using two M.2
> modules. For one module the throughput is ~350MB/s (no mdadm) for two
> modules the throughput is ~500MB/s which is less than factor 1,5 of the
> throughput of a single drive. The filesystem used is ext4. Is there
> someone having some values for comparison? For me the throughput gain
> seems to be too little. The test was done using a HP Z840 workstation.
> 

Hi Eric,

Could you attach your testing script as well, than we can have a look.



> 2.) We want to configure a softraid (raid level 0) with mdadm which can
> be used from within Linux but also it should be possible to write data
> to the raid w/ DMA directly from the FPGA which is also connected to the
> PCIe bus as a slave as well as the M.2 modules. How can that be achieved
> using existing kernel infrastructure?
> 

I don't know such existing kernel code. Maybe other people can provide
useful information.

Coly