In remembrance of Dan Williams

The following was written by Dave Hansen and Thomas Gleixner.

The Linux Kernel community mourns the unexpected and premature passing of Dan Williams.

Dan was a computer scientist with a focus on storage, persistent memory, filesystems and trusted computing. Aside from his outstanding technical contributions he served as a member and chairman of the Linux Foundation Technical Advisory Board.

His involvement with the Linux kernel started after an internship, where someone in the IT department exposed him to both the kernel and the concept of open source. In his internship, he had to work with expensive high-end RAID storage devices and he really wanted to have something like this for his home computer setup. When he discovered that Linux had recently gained software RAID support, his dream of a RAID storage system at home was just a download away. The ability to freely download, use and modify the code got him hooked; even more so when he understood that he could contribute back to share his enhancements with others. From there, it was a logical consequence that he pursued a career as a professional Linux kernel developer. His earliest traces of activity in the kernel community date back to 2004.

His early work was focused on drivers around storage technology. Following that success, he was tasked with the near-impossible mission to introduce support for a new storage technology, persistent memory, even before the hardware existed. Despite the reluctance of the filesystems and storage maintainers to cater for a hardware company's technology moonshot, Dan played a key role in the introduction of fundamentally new concepts (DAX) for this type of device and its application to existing filesystems. Building on that achievement, he led the introduction of the next generation technology named Compute Express Link (CXL) and contributed to the specification and concepts of secure devices in the context of trusted computing.

Equally important as his technical achievements - if not more so - are his contributions to the human side of the Linux community and society at large. Due to his own life experience of navigating his mixed heritage, he was a dedicated advocate and mentor for minorities in the kernel community, in the corporate context and in general society. His remarkable ability to calm down heated discussions with a well received portion of humor and playful infectious laughter, but also with a clear and honest reminder to everyone involved to focus on facts, will be truly missed.

His engagement as a member and chairman of the Linux Foundation Technical Advisory Board is a testimony for this. He significantly contributed to the interpretation of the Code of Conduct and the actual implementation in practice, to the Kernel Contribution Maturity model and the documentation of Inclusive Terminology.

One of his former managers said about him: "He's the kindest and, at the same time, the most unwavering person on the planet". That's definitely an exception in the Linux kernel community where a lot of people are unwavering, but not necessarily kind about it.

His interests went way beyond all of this. He was generally interested in all aspects of life, from human interaction to politics, technology of all sorts, philosophy and beyond. A conversation with him in and outside of the technical space was always enriching, enjoyable and filled with a good portion of his wicked humor.

He was also a passionate competitive Latin ballroom dancer. A passion which made him meet and which he shared with the love of his life Catherine, who supported him through all the highs and lows of his career, but definitely with an opinion. When Dan shared a flight with Linus, he texted her to ask what she wanted to say to him. Her answer was a dry "Merge windows suck!".

His love for Catherine and his dedication for their three kids are known to everyone who had the privilege and the pleasure to get close to him. It's heartbreaking that they are suddenly left behind without him. Our hearts and thoughts are with Catherine, their kids and their families.

For sure everyone would prefer to suffer through merge windows than having to grieve his absence, though the traces Dan left through his kindness, friendship, technical work, his humor and incredible laughter will remain woven into our lives. The French poet Antoine de Saint-Exupéry wrote in 'The Little Prince': "In one of the stars I shall be living. In one of them I shall be laughing."

Dan's traces will always bring back grief, but they should also make us look up to the laughing star he left to comfort us.

If you want to express your condolences please send an email to djbw@tglx.de. It will be passed on to the ones who he loved most.