This thread is a good example of the difference between “Linux sees the disks” and “ZimaOS considers the disks available for a new managed pool.” The user could list sdb, sdc, sdd, and sde, yet the Storage interface did not offer them for creation.
The D4-320 Is a Four-Disk USB Enclosure, Not Hardware RAID
The official TerraMaster D4-320 specifications says the D4-320 exposes four independent disks over USB 3.2 Gen2 and lists only single-disk mode; it does not provide hardware RAID or its own RAID manager. That means RAID created on a connected computer is software-defined outside the enclosure.
Why a Windows-Created Layout May Not Be Importable
A software RAID or pooled layout created in another operating system may place metadata and partitions on the disks that ZimaOS does not treat as free members. The official community reply therefore recommended wiping the existing filesystems and creating the array again through the ZimaOS GUI.
Do not wipe the disks if they contain the only copy of your data. First move or back up the data somewhere else and verify that backup.
Current ZimaOS Storage Context
The RAID recovery workflow is relevant because it shows why existing RAID metadata should not be casually overwritten. The ZimaOS 1.5 changes provides current storage-version context, while the external drive mount workflow shows how USB-attached storage can exist at the Linux mount layer even when application or storage-manager behavior differs.
CLI RAID Does Not Guarantee UI Management
The user later created RAID from the command line, but ZimaOS still did not present the array normally in Storage. The upstream mdadm RAID reference documents how Linux software RAID can be created and assembled independently of a vendor UI. A working mdadm array therefore does not prove that ZimaOS will adopt it as a GUI-managed pool.
Bottom Line
With a D4-320, treat the enclosure as four independent USB disks. If you want ZimaOS to manage them as a pool, back up any existing data, clear incompatible layouts only when safe, and create the storage through the current ZimaOS interface. Do not assume a Windows-created or manually created RAID will automatically become a ZimaOS-managed pool.
