Suggestion: Better sVDEV Planning, Oversight Tools in GUI

Cool.I wanted to demonstrate that for pools which already have a sVDEV it’s fairly trivial to figure out how much is being used for planning reasons. In your case, it’s 25.8G

Reporting this somewhere in the UI is a feature request I’d happily vote for if you want to make it.

special                                             -      -      -        -     -      -      -      -  -
  mirror-2                                      1.45T  25.8G  1.43T        -     -    14%  1.73%      -    ONLINE
    da6p1                                       1.46T      -      -        -     -      -      -      -    ONLINE
    gptid/65cf991f-90d0-11eb-acc9-ac1f6b738b00  1.46T      -      -        -     -      -      -      -    ONLINE
    gptid/6602f626-90d0-11eb-acc9-ac1f6b738b00  1.46T      -      -        -     -      -      -      -    ONLINE

I’ll amend more this weekend and look into your script also. In the meantime, I have a deadline I have to meet. Thank you for your help.

Dumb question - when writing to a single-VDEV rust, what are your transfer speeds like these days? Over 10GbE I recently transferred some large files to 1M recordsize dataset and was amazed at 400MB/s transfer speeds. Is that common now or is the sVDEV impacting this?

I max my 1Gbps copper :stuck_out_tongue:

I get about 5Gb read and writes on this pool (config seen above)


Fascinating. I’m only running a single VDEV, so I would have expected your system to be performing closer to 10GbE. Perhaps the NAS was busy with other stuff?

More likely a single threaded and single client limitation, in parallel with many is when we’d see the difference.

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So…@kris, is the reply above a good enough starting point for a resource entry re: sVDEV and if so, what would be the next steps?

Amazed good? Or amazed bad?

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Definitely amazed good! In the past the best I could hope for was 250MB/s.

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Might be something to do with not having to also write the metadata to the rust disks.

You said a single vdev… what is it ?

8x 10TB in RaidZ3?

Single z3 VDEV of eight He10 drives supplemented by a sVDEV with S3610 in 4-way mirror. I also spent a lot of time rebalancing the pool to ensure that as many small files migrated into the sVDEV as possible. Iocage and apps reside entirely on the sVDEV.

If I were to implement a VM, it would be on a dataset that lives 100% on the sVDEV of the pool.

Apologies, I don’t consider the sVDEV a second VDEV for the pool. Technically, it likely is?

Hey @kris, @will, and @Captain_Morgan,

Would you consider the sVDEV planning article above decent enough for inclusion in the Resources section?

If so, what is the process to submit such an article for consideration re: inclusion in the Resource Section since I cannot presently post there?

Absolutely I think it is. @HoneyBadger do you want to move that to resources?

What I’ve done with mine is to post them in TrueNAS General, then flag my own post, give a reason of “something else,” and then in the text field ask that it be moved to Resources.

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Done - @Constantin you can find your new Resource here: