New Server - Optimal Layout?

TrueNAS General
1

I’m converting my unraid server to TrueNAS and asked ChatGPT for recommendations. Sticking with raidz1 as most of my data isn’t critical and is also backed up on a new backup TNS server I just built. I have a couple of TB of important pics, etc that are also on an external HDD in my fire safe. Use case is basic NAS function, Emby, arrs, and will be adding Immich and Nextcloud.

Computer is a i5-13600k, 32GB ram, 240GB boot ssd, 10gb network.

Thoughts on the setup below?

:gear: Hardware Overview

  • HDDs: 5 × 8 TB

  • NVMe SSDs: 3 × 1 TB

  • SATA SSD: 1 × 1 TB

:puzzle_piece: Final Recommended Layout (TrueNAS SCALE)

1. HDD Pool – “vault”

  • Layout: RAIDZ1 (5 × 8 TB)
    → ~32 TB usable (1-disk redundancy)

  • Use: main storage (media, documents, backups, etc.)

  • Compression: lz4

  • Record size: 128 K (default)

:white_check_mark: Add caching devices to this pool:

  • L2ARC: from your SATA SSD (1 TB)

  • (Optional later) SLOG: if you add NFS/iSCSI workloads

2. SSD Pool – “flash”

Use your 3 × 1 TB NVMe drives.

  • Layout: RAIDZ1 → ~2 TB usable
    (or mirror of two + 1 spare if you want more resilience)

  • Use:

    • Apps (Kubernetes/Docker)

    • VM storage

    • Plex metadata / transcodes

    • Temporary or high-speed working files

:white_check_mark: App location in SCALE:
Go to Apps → Settings → Choose Pool → flash

3. Cache (SATA SSD)

  • Device: 1 TB SATA SSD

  • Role: L2ARC (read cache) for the vault pool
    → Accelerates frequently accessed data from HDDs
    → Ideal for metadata-heavy reads or mixed workloads

:light_bulb: Tip: L2ARC helps only if you have at least 32 GB RAM (preferably 64 GB+).
If you’re under 32 GB, L2ARC can actually slow things down.

:wrench: Example Layout Summary

Pool Drives Type Use Notes
vault 5 × 8 TB HDD RAIDZ1 Main storage ~32 TB usable
flash 3 × 1 TB NVMe RAIDZ1 Apps / VMs / Fast data ~2 TB usable
cache (L2ARC) 1 × 1 TB SATA SSD Cache for vault Improves read speeds

:brain: Recommended Settings

For vault (HDD pool)

  • Compression: lz4

  • Sync: standard

  • Atime: off (if mostly static files like media)

  • Record size: 128K (default)

  • Add L2ARC device: through Storage → Pools → Add Cache (L2ARC)

For flash (NVMe pool)

  • Compression: lz4

  • Sync: disabled (unless hosting VMs/databases)

  • Atime: off

  • Record size: 16–64K (for VM/app data)

:rocket: Resulting Benefits

:white_check_mark: ~32 TB usable on HDDs
:white_check_mark: Fast NVMe pool for apps and high I/O workloads
:white_check_mark: 1 TB SSD L2ARC for accelerated reads
:white_check_mark: Good balance of speed, capacity, and simplicity