How does qat 4xxx support ZFS

[emilio597]

I found that there is no --enable-kapi option in the Linux* Hardware v2.0 driver, but this provides a kernel interface to ZFS. Whether QAT 4xxx does not support ZFS

[Ronny_G_Intel]

Hi emilio597,

Our current QAT2.0 (out-of-tree) driver does not support QAT APIs in kernel space, which means there is no QAT2.0 (out-of-tree) support for ZFS at this time. While there is an ongoing discussion about integrating this feature into the main QAT2.0 release, there is no commitment or schedule for its implementation yet.

I can add you to our internal list of customers requesting this feature. If you could provide more details about your project, specifically the importance of having this feature enabled or implemented, it would be very helpful. Additionally, knowing whether this is just exploratory or part of an actual design would be appreciated. Information on production dates, potential volume, and your company name would also be beneficial. Please feel free to send me a private message if you are comfortable sharing these details.

Regards,

Ronny G

[Ronny_G_Intel]

Hi emilio597,

I am just checking if you have any update regarding this issue.

Regards,

Ronny G

[emilio597]

Hi Ronny G,

Thank you very much for your reply. We are currently conducting an exploratory performance evaluation of hardware compression accelerators, so we are interested in how QAT performs in terms of end-to-end performance. After learning that 4XXX cannot support ZFS, we tried the BtrFS patch in LKML, which has been tested and passed.

We noticed that BtrFS uses acomp to pass compression requests, and the performance of QAT 8970 on BtrFS is lower than that of ZFS. Is acomp's overhead higher? We still hope that 4xxx can support ZFS so that we can evaluate the performance.

Regards,

Emilio

[Ronny_G_Intel]

Hi Emilio,

I am not an expert on the Acomp framework, but if ZFS employs a more optimized compression path with potentially less overhead than BtrFS's use of Acomp, it could lead to better performance. Additionally, if Acomp's overhead is substantial, it might explain why the performance of the QAT 8970 on BtrFS is lower compared to ZFS.

Regarding support for ZFS with the 4xxx series (QAT2.0 driver), we are currently in discussions about this, and we hope that this feature will be added in the near future but no promises at this point.

Regards,

Ronny G

[Ronny_G_Intel · Accepted solution]

Hi Emilio,

Did you have a chance to review my previous post?

Please let me know if you need any further assistance. If not, I will proceed with closing the internal ticket I created for this community post.

Regards,

Ronny G

[emilio597]

Hi Ronny G,

Thanks for the help, I have no more questions.