Local SSD

BYOC runners on instance types with local NVMe SSDs (instance store) get automatic high-performance storage — WarpBuild detects the disks at boot, formats them, and mounts them to the runner's work directory. No configuration is required.

How it works

During VM boot (cloud-init), the runner automatically:

1. Detects all local NVMe SSD devices attached to the instance.
2. Creates a RAID-0 array if multiple local SSDs are found, maximizing throughput and capacity.
3. Formats the device (or RAID array) with ext4.
4. Mounts it to the runner's work directory (e.g., /home/runner/work).

The entire process completes during boot before any job starts.

Support

Choosing instance types with local SSDs

Local SSDs are only available on specific instance types. Select instance types with built-in local NVMe storage when creating your BYOC runner set:

Important notes

• Ephemeral storage — Local SSDs are tied to the instance lifecycle. All data is lost when the runner terminates. This is expected behavior since WarpBuild runners are ephemeral.
• Automatic RAID-0 — When an instance has multiple local SSDs, they are automatically striped into a single RAID-0 volume. This maximizes sequential throughput but does not provide redundancy (which is not needed for ephemeral CI workloads).
• Cross-distro support — For BYOC custom images, the mdadm package (required for RAID-0) is automatically installed if not already present. This works across Ubuntu, Amazon Linux, and other common distributions.
• No configuration needed — If the instance type has local SSDs, they are mounted automatically. If the instance type does not have local SSDs, the runner uses the regular boot disk as usual.