UGREEN NAS Storage: UGOS Pro, 16GB Reserve, and Usable Capacity
UGREEN UGOS Pro reserves approximately 16 GB system space across the storage pool. A flat deduction regardless of drive count. This is a vendor-published figure from the UGREEN RAID calculator.
See exactly how much usable storage your configuration delivers.
UGREEN UGOS Pro Storage
UGREEN's DXP series NAS devices run UGOS Pro, a Linux-based NAS operating system. UGOS Pro reserves approximately 16 GB of storage pool space for system data. This is a flat deduction (not per-drive) and is documented on UGREEN's own RAID calculator page.
UGOS Pro defaults to ext4 as the filesystem, which carries approximately 2% metadata overhead. Lower than Btrfs-default competitors.
RAID Options on UGREEN
- RAID 5. (n−1) drives usable. Three drives minimum.
- RAID 6. (n−2) drives usable. Four drives minimum.
- RAID 1. Mirror. Single drive capacity usable.
- RAID 10. Half capacity, strong performance. Four drives minimum.
- RAID 0. No redundancy, full capacity.
UGREEN does not support SHR, TRAID, ZFS RAID types, or UnRAID-style parity. It uses standard Linux mdraid.
Typical UGREEN Configurations
Estimates use defaults: 16 GB flat system overhead, 2% ext4 metadata, 10% headroom.
| Config | Advertised | Est. Usable (TiB) | For Files (TiB) |
|---|---|---|---|
| 2 × 4TB, RAID 1 | 8 TB | 3.61 | 3.25 |
| 4 × 4TB, RAID 5 | 16 TB | 10.85 | 9.77 |
| 4 × 8TB, RAID 5 | 32 TB | 21.75 | 19.57 |
Frequently Asked Questions
Is the UGREEN 16GB overhead a per-drive or flat deduction?
It is a flat deduction applied once to the storage pool, regardless of how many drives are installed. This is more favourable than Synology's per-drive model on larger arrays.
Does UGOS Pro support Btrfs?
Current UGOS Pro versions default to ext4. Check the current release notes for your firmware version, as filesystem support may expand. The calculator uses ext4 as the default for UGREEN.