vLLM 0.28 moves KV-cache offload to disk and expands its Rust serving path
The release adds tiered cache management, multimodal gRPC inference and broad accelerator work while removing several deprecated interfaces.
vLLM 0.28 is available with a wider serving surface and a set of compatibility changes that operators should review before moving existing inference deployments.
What changed
The v0.28.0 release, published August 26, adds disk as a secondary tier for KV-cache offloading, exposes out-of-tree secondary-tier managers, and reports tiering metrics. The release also extends the Rust frontend with multimodal image inference over gRPC, explicit data-parallel routing and reinforcement-learning lifecycle controls.
Model and hardware work spans Kimi-K3, DeepSeek V4, NVIDIA, AMD ROCm, Intel XPU, CPU and IBM architectures. vLLM also raises the default maximum batched-token count from 8,192 to 16,384 and enables prefix caching by default for Mamba models.
Who it affects
Teams operating large-context or disaggregated inference can use the new cache tiers and connector work to trade local accelerator memory against host or disk capacity. Platform teams exposing vLLM through custom frontends gain a more capable gRPC and Rust path.
The upgrade is not drop-in for every deployment. Bitsandbytes support moved to an out-of-tree plugin, Transformers moved to 5.15.0, runtime KV-scale calculation through calculate_kv_scales was removed, and override_attention_dtype was removed.
What to do
Test existing model runners, quantization plugins and client integrations against 0.28 before changing production images. Operators using KV offload should validate tiering behavior and renamed metrics in staging; deployments relying on removed options need configuration changes before rollout.
sources
- vLLM v0.28.0 release notesgithub.com
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