KVM/Virtualization mount host directory?

[leeroy]

Scale: TrueNAS-SCALE-22.02.1
Is there a way to mount local host directories using KVM in scale?

 

[Samuel Tai]

Unlikely. From what I understand of the SCALE roadmap, this needs Plan 9 VirtIO support, which seems to me intentionally omitted from SCALE, as implementing VM access to a cross-cluster host directory is a headache best avoided by not making the attempt.

 

[leeroy]

Interesting and also a bummer, thanks @Samuel Tai.

 

[Samuel Tai]

You can achieve functionally the same thing by sharing out the host directory via NFS or SMB, and having the VM mount that share.

Docs Hub | Accessing NAS From a VM

Accessing NAS From a VM

www.truenas.com

 

[leeroy]

Sorry, should have mentioned that I am currently doing that right now. I was curious about the performance, as I'm going to have some very heavy writes coming from a couple vm's and wasn't sure what this would do over NFS or SMB compared to some form of direct mount.

 

[Samuel Tai]

SCALE has very little performance tuning in the Angelfish release, as the priority was on correct functioning. Those who've tested SCALE vs Core have found a consistent ~25% performance deficit. Hopefully this will improve with the Bluefin release.

 

[leeroy]

Also very interesting! I had heard a little about the potential performance disparity, but haven't done an apples-to-apples comparison yet. I'll keep this in mind. We are having a few issues with Scale we are working through atm, but hope to have some meaningful comparisons once we get that sorted. Thanks again @Samuel Tai !