> ## Documentation Index
> Fetch the complete documentation index at: https://docs.coreweave.com/llms.txt
> Use this file to discover all available pages before exploring further.

# March 16, 2026 - CoreWeave AI Object Storage pre-stage cache

> CoreWeave AI Object Storage now supports proactive LOTA cache warming with a single HeadObject call

CoreWeave AI Object Storage now supports pre-staging objects into the LOTA cache. By issuing a HeadObject call with a `Range: bytes=0-0` header against any object, LOTA fetches the complete object from the storage backend and places it into the distributed NVMe cache on your GPU Nodes, without transferring a response body to your client.

## Overview

Pre-staging eliminates the "cold start" latency penalty that occurs when objects are read for the first time. With a warm cache, training, inference, and checkpoint-restore workloads access data at full cache speed from the very first byte. Key benefits include:

* **Faster first epoch**: Training jobs that start with a warm cache can see a 30-50% faster first epoch compared to cold reads.
* **Lower Time-To-First-Token**: Inference services load models from cache instead of backend storage, reducing TTFT for large models to sub-second levels.
* **Faster checkpoint restores**: Resuming training from the LOTA cache rather than remote storage minimizes downtime after failures.
* **Zero client bandwidth**: HeadObject returns only headers. All cache-fill traffic stays inside the backend CoreWeave network.
* **No SDK changes required**: Works with any S3-compatible tool or SDK (AWS CLI, boto3, s3cmd).

## Limitations

* Pre-staging caches whole objects only. Byte-range pre-fetching is not supported.
* Pre-staging only works through the LOTA endpoint (`http://cwlota.com`). HeadObject calls to the primary endpoint (`https://cwobject.com`) return metadata but do not trigger a cache fill.
* A HeadObject with `bytes=0-0` request counts as an object access triggering the transition of an object from Cold or Warm storage tiers to the Hot pricing tier. If `bytes=0-0` is not included in the HeadObject request, no tier transition will occur.

## Learn more

* [Pre-stage the LOTA cache](/products/storage/object-storage/improving-performance/prestage-cache) -- full instructions with AWS CLI, boto3, and s3cmd examples
* [About LOTA](/products/storage/object-storage/improving-performance/about-lota) -- how the Local Object Transport Accelerator works
* [Storage Pricing](https://www.coreweave.com/pricing) -- understand cost implications of tier transitions