Kristian Köhntopp
blog.koehntopp.info · Personal blog · on HN since 2017
Kristian Köhntopp, an infrastructure engineer, writes about filesystems, MySQL, Unix, messaging systems like Matrix and other technical topics.
What HN saysCommenters cite his posts on filesystem history, cache problems and Matrix's shortcomings, and one questions a complaint in his Matrix critique.
38HN people shared it
14linked it in comments
56stories submitted
2.0Kstory points
1 year agolast shared
2017people per year2026
Most-shared posts
- 150 years in filesystems: 1974 – Die wunderbare Welt von Isotopp4 people · 4 points · first shared 2023 · discussion on HN
- 2The Matrix Trashfire3 people · 308 points · first shared 2024 · 213 comments on HN
- 350 Years in Filesystems: 19843 people · 200 points · first shared 2023 · 44 comments on HN
- 4Kristian Köhntopp explains utf8mb4 in MySQL3 people · 15 points · first shared 2022 · 2 comments on HN
- 550 years in filesystems: towards 2004 – LFS3 people · 3 points · first shared 2023 · discussion on HN
- 6MySQL from Below2 people · 10 points · first shared 2021 · discussion on HN
- 7How to Build a Cycling Environment2 people · 4 points · first shared 2020 · discussion on HN
- 8Operations Review Meeting2 people · 2 points · first shared 2024 · discussion on HN
- 9The SGI XFS Filesystem2 people · 1 points · first shared 2023 · discussion on HN
- 10Utf8mb42 people · first shared 2022
- 1150 years in filesystems vnodes2 people · first shared 2025
- 12How not to run a CA1 people · 561 points · first shared 2018 · 248 comments on HN
- 13NVMe is not a hard disk1 people · 248 points · first shared 2021 · 206 comments on HN
- 14Getting out of the cloud…1 people · 204 points · first shared 2017 · 93 comments on HN
- 15Illegal and undocumented instructions found in every major vendor CPU1 people · 130 points · first shared 2017 · 26 comments on HN
What HN people wrote when they linked it
kensanata · 2017-07-18
For some long term perspective, I liked Kris' blog post "On cache problems, and what they mean for the future" ending with the following passage:
"That challenges the fundamental abstraction of Unix, though, because in Unix everything is a file, which is a linear array of bytes, and is being accessed through a file handle. Now, with Optane persistent data may be no longer behind a file handle, but a special kind of memory, and data does not have to be crystallized into serialized structures before persistence. In fact, the memory may be so fast that we might not have time to do that.
We require a different compute abstraction instead. Which means, when we have it, the result will finally, after five decades, not really Unix any more."
http://blog.koehntopp.info/index.php/1960-on-cache-problems-and-what-t…
asimops · 2025-07-17
There is a blog post that captures this feelings very well in my opinion: Not being federated and E2E as an advantage https://blog.koehntopp.info/2025/06/17/no-federation-no-e2e.html
yencabulator · 2025-03-07
avtar · 2024-04-04
> Why we would we fund Matrix when XMPP and IRC already exists?
A common sentiment I’ve come across, here and other corners of the internet, is dismay that more organizations have been adopting closed communication platforms such as Discord and Slack. These platforms (probably Discord more so) make it easier for online communities to be set up and offer relatively polished user experience compared to Matrix, IRC, or XMPP.
There was a post shared on HN a few weeks ago by a technical user and their onboarding experience with Matrix https://blog.koehntopp.info/2024/02/13/the-matrix-trashfire.html As someone who uses Matrix, I’m hoping they bridge the UX gap sooner than later.
XMPP and IRC are even further away from being viable alternatives.
thaumasiotes · 2024-02-21
> https://blog.koehntopp.info/2024/02/13/the-matrix-trashfire.... explains why Matrix is lacking market share
It complains that cyberfurz.chat is a "server with profanity in the name".
...why?
tgsovlerkhgsel · 2024-02-20
The reason Signal is successful is because it at least somewhat reliably works, while Matrix is the worst of fiddleware.
https://blog.koehntopp.info/2024/02/13/the-matrix-trashfire.html explains why Matrix is lacking market share, and I think Signal's decision to be aggressively closed is due to a justified fear of becoming that.
sthrs · 2023-05-26
This series has been really informative regarding the history of filesystems - when each breakthrough occurred and the historical tradeoffs that were considered at each point.
https://blog.koehntopp.info/2023/05/05/50-years-in-filesystems-1974.ht…
omnibrain · 2022-08-23
I don‘t know what happened, because I‘m 100% sure I posted the right URL.
https://blog.koehntopp.info/2022/08/23/mysql-gipk.html
Is the share Link I get from Twitters Webview.
compressedgas · 2022-08-23
Going by the title, the story URL should be:
https://blog.koehntopp.info/2020/01/28/some-rules-for-primary-keys.htm…
pxeger1 · 2022-06-20
This appears to be the wrong URL. It takes you to the blog homepage; the actual post is https://blog.koehntopp.info/2022/06/20/mysql-breaking-replication-with…
ruiquelhas · 2022-01-13
It kind-of is "wired" to a "physical" representation, but in a different sense.
https://blog.koehntopp.info/2022/01/12/utf8mb4.html#so-what-would-happ…
kolaente · 2022-01-12
Also relevant about this: https://blog.koehntopp.info/2022/01/12/utf8mb4.html
isotopp · 2021-06-11
If you are not running a database at home, you have the database in a replication setup.
That provides capacity, but also redundancy. Better redundancy than at the disk level - fewer resources are shared.
https://blog.koehntopp.info/2021/03/24/a-lot-of-mysql.html
Here is how we run our datatbases.
liotier · 2017-01-31
Not quite a "headfake" but indeed it is all about testing our response. This is called Lean Fascism: http://blog.koehntopp.info/index.php/255-lean-fascism/ - "Political positions are no longer backed by theory and no longer subject to political discourse and societal control. They are simply being implemented, sometimes even purposefully badly crafted, in order to measure societal reaction"