PERFORMANCE HIGH SCORE, or, how I learned about ReFS on CSV

[batiati]

Hi folks,
I've just read the PERFORMANCE HIGH SCORE news you guys released, it's amazing, congratulations!

I don't know if here on StarWind's forum is the best place to ask it, but there is a point on this benchmark that has raised a doubt: Is it mentioned that ReFS for the CSV has achieved a better perfomance than NTFS ?

"ReFS showed convenient performance overtopping the results that we had using NTFS."

I was surprised to read this, because as far as I know, when using ReFS for CSV all IO requests from other nodes have to pass through the owner node via SMB. It's called "Redirected Access".

https://www.itprotoday.com/windows-8/nt ... erver-2016

Using NTFS instead, you have "Direct Access" for all nodes directly by iSCSI, just metadata syncronizations are done through SMB on the onwer node. That is why Microsoft recomends one CSV per node, to avoid constants indirect access for metadata operations.

I couldn't find any updates about it on Windows Server 2019 documentations, but I tested it on WS2016 and confirmed: Just the owner node access the shared volume through iSCSI when using ReFS. All other nodes access it through SMB on the same LAN assigned for cluster communications.

I think that using ReFS, in the case of one VM migrate to another node (a failover for example) would impose a heavy IO penality, and worse, it could mess with your QoS setup that are optimized for iSCSI traffic.

[Oleg(staff)]

Hi batiati,
Thank you for your interest in StarWind solution and your comments regarding the article.
As you might notice, in the described configuration each of 12 volumes owns by a separate node, thus the situation you have described was avoided during the test.
Feel free to ask any other questions.

[batiati]

Hi Oleg,
Thank you for replying, I use StarWind Free on my prodution environment and I really enjoy it. It is a great product.

Just for the sake of knowledge, and preventing anyone from inadvertently choosing ReFS for their CSVs thinking they are making the best choice based on this benchmark.

Am I correct to say that "ReFS is not suitable for use on CSVs running on top of the iSCSI bus", or has anything changed on Windows 2019?

Was there such a difference in performance between NFTS and ReFS that it was justified to use ReFS on the benchmark even though it was not the right choice for production?

[Oleg(staff)]

Hi batiati,
During benchmarking we did not face any issues with ReFS on Windows Server 2019, however, our QA team is still checking the stability of such setup to advise it for production.

[Treo]

Hi batiati,
During benchmarking we did not face any issues with ReFS on Windows Server 2019, however, our QA team is still checking the stability of such setup to advise it for production.

Hi Oleg,

I am finalizing a production built for a 2 node StarWind HCI for a Hyper V cluster on Server 2019 (to be clear storage and hypervisor are on the same server). I'd like to know if there is an update for using ReFS on CSVs or to stick to NTFS in this configuration. Has any further testing taken place since your post by the StarWind QA team?

regards,
---
Louis

[Michael (staff)]

Hello,
The tests went fine, however, I would suggest using NTFS as ReFS could have some possible issues.

[Treo]

Hi Michael,

Thanks for the update, I will use NTFS.

BTW will the StarWind documentation and help files be updated from server 2016 to 2019?

[yaroslav (staff)]

Thank you for your question.
Setting up StarWind VSAN on Windows Server 2019 is exactly the same as on Windows Server 2016.
This makes "old" guides still applicable for Windows Server 2019.

[Treo]

Hi yaroslav,

I fully agree the guides for StarWind server 2016 are equally applicable to server 2019. I used the server 2016 guides and had no issues at all in setting up my lab infra and now moving on to production StarWind VSAN is a fantastic product! I do think, though, that it would be worthwhile to at least state in the guides that they are also applicable to server 2019, as more and more people are adopting 2019.

What I was heading more with my comment above was an update on some of the topics on the online help files on VSAN. e.g. the TCP/IP tweaks settings page needs some updates for server 2019 due to new features in its TCP/IP stack and the new TCP templates.

[yaroslav (staff)]

Thank you for your warm words and documentation update request!
We highly appreciate the contribution of StarWind VSAN FREE community to development of the solution.
Sure, Help should be changed to keep up the pace with the users' needs. We will do that.