In the Proxmox case with an Orico/JMicron JMS56x enclosure, the USB device reached the ZimaOS guest and the kernel detected the bridge, but no sdX block device appeared before the USB device disconnected. Passing the individual disks from the Proxmox host was the working workaround reported by the user.
One community reply attributed this to missing usb_storage/uas modules. That conclusion should be treated as a hypothesis, not a verified fact: the posted ZimaOS log itself says usb-storage ... USB Mass Storage device detected and creates a SCSI host.
What the Original Log Actually Proves
Proxmox successfully attached vendor/product ID 152d:0565 to the VM. ZimaOS then detected the JMS56x bridge and started a USB-storage SCSI host, but it never produced the expected direct-access disk lines or block devices.
The same enclosure worked in a Debian 13 VM on the same Proxmox host. That makes the ZimaOS guest environment a strong compatibility suspect, but it does not by itself identify which kernel option, quirk or bridge behavior is responsible.
Why a Failed modprobe Is Not Enough to Diagnose It
A failed modprobe usb_storage command does not prove that USB storage support is absent when the running kernel is already logging activity from usb-storage. Drivers can also be built into a kernel rather than available as loadable modules.
For this reason, do not present the forum explanation as an official ZimaOS kernel limitation unless IceWhale confirms the exact driver configuration for the current release.
Use a More Stable Passthrough Boundary
Proxmox documents host USB passthrough by vendor/product ID or by bus/port in its Proxmox VE administration guide. If the whole USB bridge does not initialize correctly inside ZimaOS, passing storage at a different layer is a practical alternative.
The original poster already found that attaching the disks to the Proxmox host and passing the host disks through to ZimaOS worked. For important data, test one disk first and make sure identifiers remain stable across reboots.
Do Not Assume ZimaOS 1.7.1 Fixed This JMS56x Case
The ZimaOS 1.7.1 changelog mentions a fix for some USB-related tasks being lost after restart. It does not mention JMS56x, UAS, USB mass-storage passthrough, or Proxmox bridge compatibility.
If you are installing ZimaOS under virtualization, the ZimaOS installation troubleshooting guide is a useful companion before changing storage passthrough architecture.
Bottom Line
The verified symptom is “USB bridge enumerates, but disks never become block devices.” Host-disk passthrough worked around it. The exact kernel-level cause was not proven in the thread, so preserve that uncertainty when troubleshooting a current ZimaOS release.
