Notes tagged
#infrastructure
29 posts
- 5 min read
The V100's memory hits 85 °C whatever I cool it with — I sold the card and I'm staying on the RTX 5070 Ti
Four attempts to cool a V100 SXM2: the HBM stops at 85 °C whatever I change. I sold the card and I'm staying on the RTX 5070 Ti.
- 2 min read
29 Hours of Silent Maximum-Depth Reasoning
Set the model to think at a moderate level. It quietly ran at full depth for over a day instead — no error, just silence.
- 3 min read
The Host Froze the First Night. Two Days Later, a Private AI That Saves ₽75,500 a Month
Bought a used GPU — the host froze the first night. Two days later: five real fixes, from power draw to the finance model.
- 3 min read
0.56 + 0.38 + 0.04 + 0.03 = 1.01
The VRAM budget for two models on one card never added up — a routine vLLM upgrade finally proved it.
- 4 min read
Qwen3.8-Flash-Next vs production 27B across three runs: 0.789 was the wrong config
New Qwen4-preview architecture against the production 27B across three runs each — and why my last post cited the wrong config.
- 3 min read
2-bit DeepSeek, Ornith-35B, and a bug in my own measurement
Three models I hadn't benchmarked before, and a scoring bug someone else caught, not me.
- 3 min read
18 quants on one card: 3x faster doesn't mean smarter
Ran 18 configurations across three models on a rented card. Got a sizing table for any VRAM budget — and one defect the vendor benchmark never showed.
- 5 min read
More memory doesn't mean faster: prefill, decode, and the Apple M5 Ultra launch
Apple shipped M6 and M5 Ultra. Working through the roofline model and real numbers to explain why prefill and decode hit different hardware walls — and who actually needs 512GB of unified memory.
- 3 min read
UDP died on the first mile
Six days ago the route seemed to have one weak link. Today an international partner pulled a match off air — UDP filtering turned up on the venue side too.
- 2 min read
SRT lost to RTMP on a long international path
SRT corrupted and froze at roughly 183 ms RTT. RTMP held on the same path because protocol choice starts with the transit network.
- 3 min read
A 135 GB VOD archive for $2–3 per month
Why HLS makes cheap object storage expensive, and how MP4 behind Cloudflare keeps a tournament archive at $2–3 per month.
- 3 min read
A 200-viewer admission limit on top of MistServer
Adding a hard viewer budget to MistServer on a 1 Gbit port, with clean per-session rejection instead of a saturated origin.
- 3 min read
My SSH key sat in a plain file — while the same chip guarded my email password
macOS has a native command for hardware SSH keys in the Secure Enclave — sc_auth. Here's what actually works.
- 5 min read
Russian open models on my own Blackwell — and where NVFP4 breaks
An open RU-model ladder on an RTX PRO 6000: the dense 27B takes the top, a 12B lands half a step behind at half the size, and NVFP4 on Blackwell came up for only one of three.
- 2 min read
Fixed NVFP4 on Blackwell — it was missing CUDA 12.9
Two Blackwell bugs turned out to be one CUDA-toolkit gap, not a vLLM bug. Both models run NVFP4 now; memory ran 4-5GB heavier than the morning estimate.
- 2 min read
Do I even need my own GPU?
VRAM is tight, rental's rising. I sat down to pick a GPU — and the real question turned out to be whether I need one at all.
- 3 min read
It's not a camera
Spent today sketching out a product that doesn't exist yet. By evening it was clear: it's not a camera. It's an AI system where the hard part runs on the phone — and I'm giving that part away free.
- 6 min read
Thirteen sites under 152-FZ in a day — and ten minutes down over a single dollar sign
Closed 152-FZ across thirteen csylabs sites in a day — and lost ten minutes of production over how docker compose reads $ in .env values.
- 2 min read
Building a platform so my team can learn how I operate
Courses, onboarding, and ops tooling should not be separate theory. They should be the environment where the team learns to ship real systems.
- 8 min read
I moved csylabs to Selectel overnight — but the story is not speed
The overnight migration from Servers.ru to Selectel took about 50 minutes of active cutover time. The point is not speed, but keeping production properties intact: mail, mesh, backups, DNS, and runbooks.
- 4 min read
Youth sports: the point is not the tournament, it is the infrastructure
Youth sports does not run on one tournament. It runs on boring infrastructure: courts, schedules, insurance, parent communication, and cheap coverage of every game.
- 4 min read
Three Proxmox-on-ZFS installs, three UEFI shells
Tried to install Proxmox with ZFS on new hardware. Dropped to UEFI shell. Not once — three times. Root cause is in how ZFS-Proxmox boots. Found the safety-net recipe; will verify on the next install.
- 3 min read
Thought it was one thing, turned out to be another: 4Kn drives broke the ZFS boot
A correction to the morning post. The root cause wasn't in systemd-boot, wasn't in the fallback path. Provider support went a layer below, swapped physical disks, and the install worked.
- 3 min read
iCloud isn't renewing — three options for the family
My sister's iCloud subscription stopped renewing — the card isn't accepted anymore, and her photos will stop syncing soon. Familiar story for a lot of people in Russia right now. Three working paths, from simplest to fully self-hosted.
- 3 min read
Notes on NFS — or why you might need Proxmox Backup Server
The previous post ended with 'let's go' — first backup running tonight. In the morning I opened the panel. Interface doesn't load. :)
- 4 min read
Spun up my own video node over the weekend
A weekend project: self-hosted streaming node with SRT in, HLS/WebRTC/RTMP out, and identifiers-as-keys instead of passwords.
- 2 min read
A backup on the same machine is not a backup
After rebuilding the infrastructure, I had to set up the backup schema from scratch — connected the home NAS to the private mesh and closed 3-2-1.
- 2 min read
Sound: yes. Video: no.
The first inbound stream hit the media server with a metadata bug — video data was on the wire but the server couldn't see it. Found it in an hour.
- 3 min read
Shipped the blog in one evening
Zero to daniel.csylabs.com in one evening. Stack, what broke along the way, and how it got fixed.