Use External Storage

Introduced in Batocera v43.

Batocera's Storage Manager allows you to expand your ROM storage across multiple drives while keeping a single unified game library. USB drives, external hard drives, SSDs, SD cards, and additional internal drives can all be used.

The Storage Manager can:

• Detect compatible storage devices automatically
• Merge existing ROM drives
• Format and prepare new drives
• Use multiple drives simultaneously
• Present all ROMs as a single library under `/userdata/roms`
• Safely eject drives
• Automatically refresh game lists

A drive must contain a root-level folder named:

roms

Supported:

Drive
└── roms
    ├── nes
    ├── snes
    └── psx

Not supported:

Drive
└── Batocera
    └── roms

When Batocera detects a mounted drive containing a compatible `roms` folder, it offers to merge the drive into the Storage Manager.

After the merge completes, the ROMs become available alongside your existing collection.

If a blank drive is detected, Batocera can automatically prepare it for game storage.

Selecting Format & Merge will erase all existing data on the drive.

Batocera will:

• Format the drive
• Create a `roms` folder
• Generate the standard ROM directory structure
• Merge the drive into the Storage Manager

Multiple drives can be used simultaneously.

Example:

/media/roms1/roms
/media/roms2/roms

Batocera combines them into a single virtual library:

/userdata/roms

The Storage Manager is not limited to removable USB devices.

Additional internal SATA and NVMe drives can also be used, provided they are mounted and contain a root-level `roms` folder.

Drives can be safely removed from:

• Main Menu
• System Settings
• Eject an External Disk

Batocera automatically updates the storage pool and refreshes game lists.

Only:

/userdata/roms

is merged.

Folders such as:

/userdata/bios
/userdata/saves
/userdata/screenshots

remain on internal storage.

Batocera uses MergerFS to combine ROM folders from multiple drives.

Current policy:

category.create=eplfs
moveonenospc=true
minfreespace=4G

eplfs means Existing Path, Least Free Space.

When writing a new file:

• A branch containing the target folder is selected
• The branch with the least free space is preferred
• Branches with less than 4 GB free are ignored
• Files can move automatically if a drive becomes full

Batocera TV – Batocera 43 - Episode II

https://youtu.be/XpH27Yswe38?t=143