Trying to test where performance drops are coming from with zfs send/recv. Is there a way to redirect 'zfs recv' to /dev/null instead of a destination pool? I want to isolate the zfs send and network without involving the writing of the snapshot to media on the destination/recv side. Everytime I try to redirect or pipe zfs recv to /dev/null it errors due to lack of a destination zpool declaration.

Hello! This is my first time writing here so sorry if I'm asking in the wrong place. I am trying to use OmniOS cloud image (latest stable) to get a system up and running for some experimentation on a paravirtualized-scsi KVM virtual machine. Unfortunately I have only the paravirtualized+SCSI option, I can't use other disk interfaces. UEFI loads the

disk correctly, loading starts, but after ZFS scan it starts to have errors with reading the pool label. Can it happen because there is no virtio-scsi driver included in the cloud image, or it should be working correctly and the erroris somewhere else? Thank you in advance.

Guest72 Yes, you're right. The virtio-scsi is not part of the cloud image, we should fix that!

Let me know if you'd like a new image to test with for a particular version

Hello, former guest72 here just I had to log out. Thank you for your answer. Unfortunately I'm very much a beginner in all of this, that's why I was thinking about experimenting with it, but how difficult would it be to include it into the cloud image? If it's easy, and if there are any documentation available in general about building the cloud

image or including additional components, I can give it a try and then contribute it. I didn't do kernel development before, but I'm familiar with git, packaging concepts (more experience with APT though), previously I built some Debian images with debootstrap and compiled Linux kernel so build systems, C/C++, kernels and such concepts aren't

foreign for me.

Hi - it's easy enough to add it to the image, and I've opened some pull requests to do it. If you let me know which version you are using, I can build a new cloud image with the driver in it.

The cloud image (and all of the other media) gets built from github.com/omniosorg/kayak

Thank you! I tried the stable release r151048, so if you could provide me an image for that it would be awesome.

Ok, I'll let you know when it's ready

Thank you

Which format do you want it in? raw, vmdk etc.

Well I guess raw image size would be much bigger, so VMDK is fine for me, and then later I'll convert it to raw.

Also sorry just one more question, I cloned Kayak repository, but it's readme mentions only how to make the ISO and USB images and their dependencies, but it doesn't mention the cloud image, does it have any option which is not documented in Kayak's readme file? I'm just asking if for some reason in the future I'd like to try out modifying

something for myself.

Yes, the README needs an update. I modified build/zfs_send to make sure it installs the vioscsi package, then ran:

PKGURL=pkg.omnios.org/r151048/core pfexec gmake build-cloud

Here you go: downloads.omnios.org/misc/omnios-r151048i.cloud+vioscsi.vmdk

The SHA256 is 6307e2f2ea5a804fe67c3704cfda798fe740efa1a945cb4473d41f7742e185f3

Awesome, thank you very much!

By the way if I start to looking into this, what do you think, is there anything minor thing I could attempt to do? It would be interesting to try myself out in an open-source project, but I am really new in such things so I can't jump right into... FS or drivers or kernel development or etc.. But if I will have some free time it would be

interesting to try to work on something useful.

(And sorry if I write something redundantly - I'm not native english-speaker so sometimes I overcomplicate sentences a bit)

There are definitely some small issues in the illumos tracker that could be suitable for getting started. It's worth looking through that.

Here are the issues marked as bite sized which have no person assigned to them

Some of them might have the wrong difficulty set, but hopefully there's something there that you think you could work on, and thanks :)

andyf you are purely awesome

Great, I will look at it and find something to start with, thank you!

This mirroring guide is taking longer than I expected. I just finished the setup part.

Okay, hopefully one more hour to go.

Is there a way to apply live tuning changes? I know I can set params in /etc/system and on reboot they apply. If I am testing zfs performance is there a ways to apply zfs tune changes in real time and have them take effect immediately? zfs params like zfs_vdev_async_write_max_active for example? I know some params can only be set at load time such as metaslab_debug_unload. the vdev_*_max_active params can be changed live in Linux. Not sure

how to accomplish this, or if it is even possible in OmniOS

aeonjeffj - you can tune them live with mdb.

mdb -kwe <variable>/z<value>

Thanks!