Taras Glek

Why Google Pixel lags 10x more than Moto Z

Cloudflare Pages: Best server tech since CGI-bin?

Cloudflare Pages 😍 I got into Cloudflare pages because it lets you host static websites with all the latest optimizations conveniently and for free. Setting up a static website with a custom domain is easy, and you get the benefits of automatic SSL, CDN, and latest version of HTTP3. This is how this blog is hosted and…

Firefox's Optimized Zip Format

This post is about minimizing amount of disk IO and CPU overhead when reading Zip files. I recently saw an article about a new format that was faster than zip. This is quite surprising as to my mind, zip is one of the most flexible and low-overhead formats I’ve encountered. Some googling showed me that over past 11…

Maintaining sufficient free space with ZFS

TLDR: ZFS free-space reporting is a lagging indicator. Background I use Proxmox VM server backed by a ZFS array of hard drives for various personal infrastructure. I also have security cameras that upload motion-triggered videos to my server (via FTP!). Problem Description I would like to use 90% of my available space…

Reading NFS at 25GB/s using FIO and libnfs

My current employer does a lot of really cool systems work that’s covered by NDAs. I recently did some work to integrate a cool open source tool into our workflow. Felt it deserved a blog post. NFS Testing Requires Parallelism. I work for Pure Storage. One of the products we make is a scale-out NFS1 (and…

eBPF for tracing how Firefox uses page faults to load libraries

Modern browsers are some of the most complicated programs ever written. For example, the main Firefox library on my system is over 130Mbytes. Doing 130MB of IO poorly can be quite a performance hit, even with SSDs! :). Few people seem to understand how memory-mapped IO works. There are no pre-canned tools to observe…