ZFS: The Last Word in File Systems Part 1
Why Hacker News recommends it
HN recommends it as the definitive explanation of ZFS design straight from its inventors, with war stories about data integrity.
Recommended by 4 people across 4 different months, 2016 to 2026.
What it is
Jeff Bonwick and Bill Moore, the creators of ZFS, present 'ZFS: The Last Word in File Systems' at the 2008 SNIA Software Developers' Conference. They explain the design, including copy-on-write, checksumming and avoiding the write hole.
What people said
Strong rec tnorgaard · 2016-06 · Hacker News · on “A ZFS developer’s analysis of Apple’s new APFS file system”
I would recommend anybody interested in filesystems to watch Jeff Bonwick (ZFS inventor) explain the design of ZFS: [this video] . They have a few very nice war stories explaining why they found it useful to have the user data checksummed as well.
Strong rec throw0101a · 2019-10 · Hacker News · on “Ubuntu installer now supports ZFS on the boot partition”
> Is ZFS any good? The presentation "ZFS: The Last Word in File Systems" from its debut in 2008 is a good introduction. Part 1 (of 3) probably best explains how different it is from just about anything else out there (even now, in 2019): * [this video] Part 2 show some extra niceties / features, and Part 3 is a demo and Q&A. Watching Part 1 at least is worth it for anyone curious; 2 and 3 are optional.
Strong rec jorangreef · 2023-11 · Hacker News · on “”
ZFS was an inspiration for TigerBeetle. I love this talk by Jeff Bonwick and Bill Moore: “ZFS: The Last Word in File Systems” [this video]
Recommends solarengineer · 2026-01 · Hacker News · on “FreeBSD: Home NAS, part 1 – configuring ZFS mirror (RAID1)”
ZFS: The last word in File Systems: Part 1: [this video] Part 2: [LINK] ZFS In the trenches: [LINK] Some good stuff here: [LINK]
Cites throw0101a · 2020-09 · Hacker News · on “Preserving data integrity: A ZFS-inspired storage system”
Well, ZFS isn't exactly monolithic if you look under the hood: it has the ZPL (files, directories), DMU (objects, transactions on those objects), SPA (actual disk I/O). A potato-quality video from 2008 with Moore and Bonwick, the creators (timestamped to relevant section): * [this video]
Cites throw0101a · 2021-04 · Hacker News · on “Btrfs on Zoned Block Devices”
> initial issues You mean like the current advice not to use anything except mirroring and striping (RAID-0/1/10)? > Parity may be inconsistent after a crash (the "write hole"). The problem born when after "an unclean shutdown" a disk failure happens. But these are two distinct failures. These together break the BTRFS raid5 redundancy. If you run a scrub process after "an unclean shutdown" (with no disk failure in between) those data which match their checksum can still be read out while the mismatched data are lost forever. * [LINK] I've been using ZFS since it came out on Solaris 10 over a decade ago and it was specifically designed not to have a write hole due to its COW/ACID nature. See