# Atlantis (DS1823xs+) Storage Configuration

## Overview

Atlantis is a Synology DS1823xs+ NAS running DSM 7.3.2. This document details the storage configuration and performance characteristics.

## Hardware

- **Model**: Synology DS1823xs+ (8-bay)
- **CPU**: AMD Ryzen V1780B (4 cores)
- **RAM**: 32GB ECC
- **DSM Version**: 7.3.2-86009

## Storage Volumes

### Volume 1 - Main Storage (SATA RAID6)
| Property | Value |
|----------|-------|
| Drives | 8x Seagate 16TB SATA |
| RAID Level | RAID 6 |
| Usable Capacity | 84 TB |
| Filesystem | Btrfs |
| Encryption | Yes (LUKS) |
| Write Speed | ~77 MB/s |
| Read Speed | ~212 MB/s |
| Mount Point | `/volume1` |
| Purpose | Primary data storage, media, backups |

### Volume 2 - Fast Metadata (NVMe RAID1)
| Property | Value |
|----------|-------|
| Drives | 2x Crucial CT1000P310SSD8 (1TB each) |
| RAID Level | RAID 1 |
| Usable Capacity | 885 GB |
| Filesystem | Btrfs |
| Write Speed | ~422 MB/s |
| Read Speed | ~435 MB/s |
| Mount Point | `/volume2` |
| Purpose | Docker configs, databases, metadata |

### Volume 3 - Fast Downloads (NVMe RAID1)
| Property | Value |
|----------|-------|
| Drives | 2x Synology SNV5420-400G (400GB each) |
| RAID Level | RAID 1 |
| Usable Capacity | 348 GB |
| Filesystem | Btrfs |
| Write Speed | ~621 MB/s |
| Read Speed | ~706 MB/s |
| Mount Point | `/volume3` |
| Purpose | SABnzbd downloads, high-I/O temporary storage |
| Created | 2026-02-01 |

## NVMe Drive Layout

| Device | Model | Slot | Volume |
|--------|-------|------|--------|
| nvme0n1 | Synology SNV5420-400G | M.2 Drive 1-2 (built-in) | Volume 3 |
| nvme1n1 | Synology SNV5420-400G | M.2 Drive 1-1 (built-in) | Volume 3 |
| nvme2n1 | Crucial CT1000P310SSD8 | M.2 Drive 1 (adapter) | Volume 2 |
| nvme3n1 | Crucial CT1000P310SSD8 | M.2 Drive 2 (adapter) | Volume 2 |

## Volume 3 Creation Notes

Volume 3 was created using [007revad's Synology_M2_volume script](https://github.com/007revad/Synology_M2_volume) since DSM's Storage Manager doesn't allow creating M.2 storage pools when another M.2 pool already exists.

### Script used:
```bash
sudo ~/syno_create_m2_volume.sh
```

### Configuration selected:
- RAID Type: RAID 1
- Storage Pool Type: Single Volume
- Drives: nvme0n1 + nvme1n1 (Synology SNV5420)
- Filesystem: Btrfs

### Important Notes:
- Since these are **Synology-branded drives** (SNV5420), they should survive DSM updates without needing the Synology_HDD_db script
- After DSM updates, verify the volume is still accessible. If not, re-run the M2_volume script
- The SNV5420 drives are enterprise-grade with power loss protection (PLP)

## SSD Cache Limitation

**Warning**: The DS1823xs+ has `support_ssd_cache="no"` as a factory default, which prevents using M.2 drives as SSD cache. This appears to be a Synology policy decision for the xs+ line. Combined with the "M.2 storage pool disables all M.2 cache" limitation, SSD cache is not available on this system.

## Performance Comparison

| Volume | Write Speed | Read Speed | Best For |
|--------|-------------|------------|----------|
| Volume 1 (HDD) | 77 MB/s | 212 MB/s | Large file storage |
| Volume 2 (Crucial NVMe) | 422 MB/s | 435 MB/s | Docker configs, databases |
| Volume 3 (Synology NVMe) | **621 MB/s** | **706 MB/s** | Downloads, high-I/O temp |

## Docker Volume Mapping Strategy

```
/volume1/data           → Media files, final storage
/volume2/metadata/docker2 → Container configs and databases  
/volume3/usenet         → SABnzbd downloads (fast writes)
```

The arr-suite containers (Sonarr, Radarr, etc.) are configured to:
1. Download to `/volume3/usenet` (fast NVMe)
2. Process/unpack on `/volume3/usenet` (fast NVMe)
3. Move completed media to `/volume1/data/media` (large HDD storage)

## Related Files

- Arr Suite Compose: `Atlantis/arr-suite/docker-compose.yml`
- This documentation: `docs/hardware/atlantis-storage.md`
