Date:   Tue, 30 Nov 2021 17:20:25 +0100
From:   Piergiorgio Sartor <piergiorgio.sartor@nexgo.de>
To:     Paul Menzel <pmenzel@molgen.mpg.de>
Cc:     linux-raid@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
        linux-accelerators@lists.ozlabs.org, linux-nvme@lists.infradead.org
Subject: Re: Using aGPU for RAID calculations (proprietary GRAID SupremeRAID)
Message-ID: <YaZPScnojOLqDNPc@lazy.lzy>
References: <ccdbb0d7-d043-d41f-508b-4a464ffa5fe9@molgen.mpg.de>
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On Tue, Nov 30, 2021 at 12:58:10PM +0100, Paul Menzel wrote:
> 
> Dear Linux folks,
> 
> 
> I read about GRAID SupremeRAID [1], which seems to be an Nvidia T1000 card
> and software to use the card for RAID calculations.
> 
> > GRAID SupremeRAID works by installing a virtual NVMe controller onto
> > the operating system and integrating a PCIe device into the system
> > equipped with a high-performance AI processor to handle all RAID
> > operations of the virtual NVMe controller
> 
> According to the review *GRAID SupremeRAID SR-1000 Review* [2] it performs
> quite well. I couldn’t find any driver files online.
> 
> Now I am wondering, why a graphics card seems to help so much. What
> operations are there, modern CPUs cannot keep up with?
> 
> If GPUs are that much better, are people already working on a FLOSS solution
> for the Linux kernel, so people can “just” plug in a graphics card to
> increase the speed?
> 
> Does the Linux kernel already have an API to offload calculations to
> accelerator cards, so it’s basically plug and play (with AMD graphics cards
> for example using HSA/KFD)? Entropy sources, like the ChaosKey [3], work
> like that. If not, would the implementation go under `lib/raid6`?

I think this was somehow discussed here
some times ago.
That is the use of "GPU" to accellerate
the parity computation.

There are a couple of things to keep in mind.

One is the data transfer to / from the video
card, which might be a bottleneck.
At any rate, there will be a write and read
streams going across the system bus(es).

An other point is that, unless an high end
video card is used, with ECC memory, the
reliability of the whole process might be
of concern.

Finally, usually video cards, while having
a lot of memory (caching could be good),
they miss the battery backup.
Power is off, data is gone...

bye,

pg

> 
> 
> Kind regards,
> 
> Paul
> 
> 
> [1]: https://www.graidtech.com/post/graid-reveals-the-next-generation-of-enterprise-data-protection-nvme-ssds
> [2]: https://www.storagereview.com/review/graid-supremeraid-sr-1000-review
> [3]: https://altusmetrum.org/ChaosKey/
> 

-- 

piergiorgio