# Storage

> Create or import the storage pool.

Source: https://docs.univrs.cloud/setup/storage/

_Choosing a pool layout_

virgoOS keeps your apps and data on a redundant storage pool built from the node's drives. The drive the system runs from is never part of the pool.

The pool needs:

- **At least 2 data drives.** The drive the system runs from does not count.
- **Drives of the same type.** Hard drives, SATA SSDs and NVMe drives never share a pool. When the node has more than one type, Setup offers layouts for each type separately, and the pool is built from one of them.
- **Drives of the same size.** The smallest drive may be at most 10% smaller than the largest. Capacity is calculated from the smallest drive.

Setup offers the layouts your drives support. The recommended one is listed first and already selected.

| Layout | Survives |
| --- | --- |
| Low latency (Mirror) | 1 drive failure |
| Basic protection (RAID-Z1) | 1 drive failure |
| Advanced protection (RAID-Z2) | 2 drive failures |
| Ultimate protection (RAID-Z3) | 3 drive failures |

Mirror pairs the drives up, and each pair survives 1 failure. With an odd number of drives, one drive is left out of the pool.

Some layouts can be built two ways. **More space** puts all the drives in one group. **Faster** splits them into smaller groups, and each group survives that many failures. When the drives do not split evenly, the faster layout leaves one drive out of the pool.

These examples show the layouts Setup offers for hard drives of the same size.

**2 drives**

_Layouts offered for 2 hard drives_

**3 drives**

_Layouts offered for 3 hard drives_

**4 drives**

_Layouts offered for 4 hard drives_

**5 drives**

_Layouts offered for 5 hard drives_

**6 drives**

_Layouts offered for 6 hard drives_

**8 drives**

_Layouts offered for 8 hard drives_

Each option shows the usable capacity and how many drives go to protection. Pick one and select **Create pool**.

_Confirming the pool_

Creating the pool erases everything on the drives, and the layout cannot be changed after setup. Tick **I understand and want to proceed**, then select **Format and proceed**.

_The finished pool_

If the drives already hold this node's pool, for example after reinstalling, setup offers **Import pool** instead. Importing keeps everything the pool holds. If the drives hold a pool from another system, setup warns you that creating a new pool destroys it. Use **Scan again** after attaching or removing drives.