Scenario for TrueNas HA with Proxmox


Jun 23, 2022
Hello Everyone,

Has anyone tried using the below method to achieve HA on TrueNas with Proxmox.

Create a virtual machine with 2 identical disks
Each disk is on a different storage ( NFS mapped to dataset on Truenas )
Set both disks as bootable.
Install operating system inside virtual machine using Software raid 1 configuration.

Technically, if one of the storage's fails or become offline, and assuming Proxmox will let the VM boot, the VM should not be affected.
From the VM perspective it will look like a physical disk in a Raid 1 array is offline, and operations can continue in degraded state, and when it comes back online, the array gets rebuilt.

What could be the overhead on the proxmox host CPU and Memory, i assume IO Delay will be spiking due to the disk syncing at all times.
What would be proxmox best virtual disk options for the VM, is it okay to still use write-back?
What would be the best configuration at the Truenas vdev and dataset level, Mirrors, Metadata special vdevs...

Going further
What if storage one be flash based and storage two be Hard Drive based? this will greatly improve on cost...

Going even further
Can Proxmox auto-magically provision two disks at the same time? :D
Maybe if using API's, this could help with auto-provisioning tools such as Module's Guarden Proxmox Module for WHMCS.

I believe this could be an interesting topic, appreciate your feedback and comments

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No, there is nothing in the product that would create such a configuration automatically or even close to it.
The performance will be terrible even on all flash, with half HDD it will be as bad as full HDD.
By adding so many extra layers you will be increasing probability of failure, not decreasing it.
Even a momentarily flaky connectivity could lead to near full resync on a moderately busy system, which in turn will bring the performance to a halt.

Blockbridge : Ultra low latency all-NVME shared storage for Proxmox -
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