Skip to content
Problems.

vLLM users keep filing bugs

MLOps18 posts from 18 people12d active+55 posts in the last 7 days, 1 the 7 days before (rising)

Posts per day

Posts per day18 posts, Aug 27 to Sep 25

The posts behind it

18, newest first
PostDate
VLLM 4x rtx 3060 vs 8x rtx 3060 performance loss...beyond 4 GPUs will drastically hurt my token generation speeds because of the PCIe bottleneck? But is that regardless of what GPUs I'm running? . I know for example RTX 3090 needs more PCIE bandwidth because it's much more performant and will spit out much more data that needs...r/LocalLLaMAu/snakeat3rrSep 25today
[ROCm][Perf][Tracking Issue]: Hy4-Preview### 🚀 The feature, motivation and pitch This issue is intended as a parent ticket for all work enabling and optimizing Hy4-Preview on ROCm hardware. # Enablement - [not merged] https://github.com/vllm-project/vllm/pull/54432 - [not merged]...vllm-project/vllmjamesETsmithSep 24yesterday
Advice for single 9700 on windows...for other things as well, so I'm not looking to switch. Anybody have some up to date advice on running a single 9700 on windows?. Edit: For anybody in the future, I ended up using WSL to load this beautiful man's vLLM build :...r/LocalLLaMAu/bruns20Sep 24yesterday
[RFC]: Increase vLLM Review Capacity with a Reviewer Role## Motivation vLLM’s contribution volume exceeds its available review and triage capacity, creating a massive PR backlog. To help address this backlog and stem its future growth, we propose a **Reviewer** role to expand the community of trusted reviewers who take ownership of...vllm-project/vllmLucasWilkinsonSep 232 days ago
[Installation]: v0.30.0 CPU wheels now require manylinux_2_39 (glibc 2.39), breaking installation on Ubuntu 22.04/Rhel9### Your current environment - OS: Ubuntu 22.04 LTS (glibc 2.35) / Rhel9.6 (glibc 2.34) - Arch: x86_64 - Python: 3.10 - Installing: `vllm-0.30.0+cpu-cp38-abi3-manylinux_2_39_x86_64.whl` from the GitHub release assets ### How you are installing vllm ### Description Hi vLLM team...vllm-project/vllmrebel-shshinSep 232 days ago
Logs: Logs view crashes on long lines...before? Maybe long ago when https://github.com/grafana/grafana/pull/26405 existed ### How do we reproduce it? I am not sure if this works but I would assume so 1. Use Grafana Drilldown 2. search a log stream with long log lines. In our case it was litellm logging errors returned...grafana/grafanacurious-broccoliSep 1510 days ago
[Bug]: vLLM 并发缺陷报告：6 项确认缺陷## A. 概述 本报告是针对 **vllm-project/vllm**（github.com/vllm-project/vllm）的并发安全审查结果。审查基于 commit `a46f3eb2`（2026-06-23）完成初始分析，并对照撰写日最新 main `b28c3e15`（2026-09-10）逐项重新核验了每一处代码位置与修复状态--期间 `multiproc_executor.py` 有 11 个提交、`shm_broadcast.py` 与 `kv_events.py`...vllm-project/vllmCzile-createSep 102 weeks ago
[Bug]: qwen4_exp (Qwen3.8-Flash-Next) cannot serve DeepSpec DFlash/DSpark drafters: five blockers, patches available### The problem `Qwen4ExpForConditionalGeneration` (Qwen3.8-Flash-Next) cannot serve a DeepSpec-trained DFlash or DSpark drafter on vLLM. Five independent code paths block it, four of which are small control-flow issues and one of which is architectural. None of them is about...vllm-project/vllmseanphanSep 92 weeks ago
[RFC]: Application-Directed Prefix Checkpoints for Mamba / Hybrid Prefix Caching...The core dilemma is that **from an engine-internal perspective, it is virtually impossible to heuristically predict where that single, high-value checkpoint boundary should be placed**. Geometry-based interval chopping frequently misses the actual shared premise or prematurely...vllm-project/vllmnicholaskh-aiSep 72 weeks ago
[RFC][EPD] Avoid redundant encoder work when Prefill can reuse KV or embeddings## Motivation In an E-first EPD deployment, Encoder work can start before the selected Prefill instance determines whether reusable KV or embeddings already satisfy the relevant multimodal input. This creates a potential mismatch between the work started on E and the work...vllm-project/vllmjiaran-kingSep 72 weeks ago
[RFC]: [Tracking] Heterogeneous-TP KV sharing in Mooncake Store Connector## Motivation Mooncake Store originally tied object keys and payload layout to the local TP rank. Two vLLM instances using the same model but different TP sizes therefore produced different shard counts, KV-head ranges, and namespaces and could not reuse each other's persisted...vllm-project/vllmz-zanezSep 62 weeks ago
[Bug]: qwen3.8-flash-next: assert numerator % denominator == 0, "{} is not divisible by {}".format### Your current environment The output of python collect_env.py ### 🐛 Describe the bug error: ### Before submitting a new issue... - [x] Make sure you already searched for relevant issues, and asked the chatbot living at the bottom right corner of the [documentation...vllm-project/vllmAlireza3242Sep 62 weeks ago
[Bug]: occasional gross error in memory profiling### Your current environment I can not do this, the problem happens only sometimes, usually not. It happens during automated testing in a Kubernetes cluster, and the Pods are deleted at the end of the test. I am reporting evidence gathered using a PR that adds debug info...vllm-project/vllmMikeSpreitzerSep 33 weeks ago
[FA4][SM100] Support head_dim=256 with seqused_k for paged varlen attention## Summary ### Agent Notes FA4's SM100 `head_dim=256` forward specialization rejects `seqused_q` / `seqused_k`. This blocks Qwen3.5-9B inference through PyTorch's `torch.nn.attention.varlen.varlen_attn_out` in vLLM, where causal paged KV attention supplies `block_table` and...pytorch/pytorchdrisspgSep 13 weeks ago
Support Qwen3.x MTP (Multi-Token Prediction) for speculative decoding## Summary Following analysis of 1Cat-vLLM's MTP-based speculative decoding for Qwen3.6-35B-A3B, this issue proposes adding MTP (Multi-Token Prediction) speculative decoding support f...[truncated]ggml-org/llama.cpphernandez42Aug 303 weeks ago
[RFC]: Weight version attribution for RL rollouts and Background survey## Motivation #48306 already covers weight-version metadata. The main open question is whether one value per request is enough when that request can continue through a weight update. ### vLLM already allows a request to straddle a weight update `/pause` accepts `mode="keep"`,...vllm-project/vllmShuoleiWangAug 303 weeks ago
[Bug][CPU] GLM-5.x (glm_moe_dsa) cannot run on CPU: sparse attention forced by config, no way to disable## Environment - vLLM version: v0.28.0 - Platform: Apple Silicon (M3), macOS 15.7.4, CPU backend - HF transformers: 5.16.1 - Model: `zai-org/GLM-5.2` (`glm_moe_dsa` / `GlmMoeDsaForCausalLM`) ## Bug Any GLM-5.x model (DSA / sparse-attention architecture) fails during engine...vllm-project/vllmsunlei1992Aug 274 weeks ago
[Bug]: torch profiler hangs on ROCm after rocprofiler-sdk 1.3.2 bump### Your current environment The output of python collect_env.py ### 🐛 Describe the bug Starting the torch profiler after #53182 **causes the engine to hang indefinitely**, spinning on rocprofiler-sdk's queue interposition. ### Short term fix Setting...vllm-project/vllmsimondanielssonAug 274 weeks ago

Companies and products named

Company or productPosts naming it
vLLM18
GitHub8
NVIDIA5
Kubernetes3
llama.cpp2
Qwen1
About this problem

Evidence

18 posts from 18 people in 5 places, about 4 a week over 30 days. Mostly on vllm-project/vllm, r/LocalLLaMA, ggml-org/llama.cpp. Tools named alongside: GitHub, NVIDIA, Kubernetes, llama.cpp.

Frustration Frustration 1 of 3· Seen on GitHub issues, Reddit

How it was grouped

Posts about vLLM that state a pain but match no known issue yet. First post Aug 27, 2026, latest Sep 25, 2026. Corroborated: 3 or more posts from 2 or more people or places. Method

History

  • 2026-09-25 Statement: vLLM users keep asking for help to vLLM users keep filing bugs
  • 2026-09-25 Added: vLLM users keep asking for help (17 posts)

Rising problems by email

Mondays: the problems in data, tech and AI that grew fastest that week.

Double opt-in. Unsubscribe any time.