Re: [PATCH v20 00/12] Implement copy offload support

From: Hannes Reinecke
Date: Tue Jun 04 2024 - 03:17:10 EST


On 6/4/24 06:32, Christoph Hellwig wrote:
On Mon, Jun 03, 2024 at 10:53:39AM +0000, Nitesh Shetty wrote:
The major benefit of this copy-offload/emulation framework is
observed in fabrics setup, for copy workloads across the network.
The host will send offload command over the network and actual copy
can be achieved using emulation on the target (hence patch 4).
This results in higher performance and lower network consumption,
as compared to read and write travelling across the network.
With this design of copy-offload/emulation we are able to see the
following improvements as compared to userspace read + write on a
NVMeOF TCP setup:

What is the use case of this? What workloads does raw copies a lot
of data inside a single block device?


The canonical example would be VM provisioning from a master copy.
That's not within a single block device, mind; that's more for copying the contents of one device to another.
But I wasn't aware that this approach is limited to copying within a single block devices; that would be quite pointless indeed.

Cheers,

Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
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