The November 2025 thread identified a real product limitation: on ZimaOS 1.5.2 with ZimaClient 2.3.1, a PC backup could not select a USB-connected disk as its destination even though ZimaOS itself detected the drive. IceWhale staff confirmed that this did not match the intended product design and said the client feature was under development.
Current documentation is broader than the old thread, but it still helps to separate the desktop-client backup flow from the dashboard Backup app, because they are not the same workflow.
What the User Actually Saw
The external disks were visible in ZimaOS, which ruled out a simple detection failure. The limitation appeared specifically in destination selection and related migration workflows.
What IceWhale Confirmed in the Thread
An IceWhale reply said the dashboard Backup app could use a USB drive as a destination, while the backup feature inside the desktop ZimaClient could not do that at the time. Another official reply said “PC file backup to USB-connected storage” was under development.
What the Current Documentation Says
The current computer backup guide says ZimaClient can send computer folders to a storage space such as a single disk or RAID array. It does not explicitly state that every raw USB device can be selected directly inside the desktop client.
The current 3-2-1 Backup guide is clearer about the dashboard Backup app: USB can be a source or destination, and external drives are part of the supported backup model.
Use the Dashboard Backup App as the Safer Fallback
If your current ZimaClient still refuses a USB-backed destination, do not assume the disk is broken. Back up the PC to a normal ZimaOS storage space, then create a second Backup-app task that copies that backup to the external drive. That gives you a second media copy and is easier to verify than relying on one unsupported picker path.
The backup separation guide explains why an external copy should remain separate from the live pool. The ZimaOS backup overview gives additional context on the current From/To backup model.
Bottom Line
The old ZimaClient limitation was officially acknowledged. Current ZimaOS documentation now supports much broader backup destinations, especially through the dashboard Backup app, but it does not clearly promise that every USB device will appear directly in every ZimaClient destination picker. If the picker still blocks the drive, use the dashboard Backup app and verify a restore rather than forcing the client.
