Local SSD
How WarpBuild BYOC runners automatically detect, format, and mount local NVMe SSDs to the runner work directory for maximum I/O performance
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:
- Detects all local NVMe SSD devices attached to the instance.
- Creates a RAID-0 array if multiple local SSDs are found, maximizing throughput and capacity.
- Formats the device (or RAID array) with ext4.
- Mounts it to the runner's work directory (e.g.,
/home/runner/work).
The entire process completes during boot before any job starts.
Support
| Runner type | Local SSD auto-mount |
|---|---|
| BYOC: AWS (Linux) | ✅ |
| BYOC: GCP (Linux) | ✅ |
| BYOC: Azure (Linux) | ✅ |
| Windows | ❌ |
| macOS | ❌ |
Local SSD auto-mount is only available on Linux-based images. Windows and macOS runners are not supported.
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:
| Cloud provider | Example instance types |
|---|---|
| AWS | c5d, m5d, r5d, i3, c6id, m6id, r6id families |
| GCP | -lssd machine types: c3-standard-88-lssd, c4a-standard-4-lssd, etc. |
| Azure | VM sizes with local NVMe temp storage (e.g., Lsv3, Lasv3 families) |
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
mdadmpackage (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.