Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Gnu/Hurd strikes back: How to use the legendary OS in a (somewhat) practical way

mhatta.medium.com

Post reply on HN
Print view View original

261–270 of 273 posts

Re: Gnu/Hurd strikes back: How to use the legendary OS in a (somewhat) practical way

#261

Post by effie »

JohnFen wrote: post #237
effie wrote: post #172

Earlier quoted context omitted.

Simple filesystems - those oriented at speed, without integrity checking, compression, encryption and raid-like features. Which are extremely useful and desirable in a filesystem. When people tried to do a full-featured filesystem, with a remarkable exception (ZFS) it's either a disappointing unfinished mess (btrfs) or a promising, but a long-term project taking years (bcachefs). Making a filesystem with strong suppo…

Filesystems aren't complex to implement -- even complex filesystems. What's harder is making them as robust as they need to be for practical daily use. Doing that is a matter of comprehensive testing, though. With filesystems, the hard part is QA, not implementation.

Oh it's word games with "implement". OK then, let's agree then developing a modern filesystem into a robust software for practical daily use is hard.

Re: Gnu/Hurd strikes back: How to use the legendary OS in a (somewhat) practical way

#262

Post by effie »

spookie wrote: post #235
effie wrote: post #172

Earlier quoted context omitted.

Simple filesystems - those oriented at speed, without integrity checking, compression, encryption and raid-like features. Which are extremely useful and desirable in a filesystem. When people tried to do a full-featured filesystem, with a remarkable exception (ZFS) it's either a disappointing unfinished mess (btrfs) or a promising, but a long-term project taking years (bcachefs). Making a filesystem with strong suppo…

I'm sorry, as I keep hearing these criticisms around BTRFS, I still don't know why. What is so messy about it? Honest question

It's "perpetually half-finished". Convoluted admin cli tooling, bad track record with reliability and loss of data, lots of stories on the internet. It perhaps got better, but RAID5/RAID6 for metadata (standard use of disks) still not oficially recommended and thus standard RAID5/RAID6 is not reliable. Also, look at some FS benchmarks - BTRFS is still much slower than EXT/XFS, and slower than ZFS.

About the only class of scenarios to use BTRFS instead of ZFS is if you want the features, do not need RAID5/6, require support by Linux distributor/kernel developers or for some other (hard to think of) reason you can't use ZFS.

I do use BTRFS on a single disk where I don't touch it with cli tools, and there it's fine.

Re: Gnu/Hurd strikes back: How to use the legendary OS in a (somewhat) practical way

#263

Post by effie »

Foobar8568 wrote: post #185
effie wrote: post #172

Earlier quoted context omitted.

Simple filesystems - those oriented at speed, without integrity checking, compression, encryption and raid-like features. Which are extremely useful and desirable in a filesystem. When people tried to do a full-featured filesystem, with a remarkable exception (ZFS) it's either a disappointing unfinished mess (btrfs) or a promising, but a long-term project taking years (bcachefs). Making a filesystem with strong suppo…

Hammer2 comes to mind as well..

Does it run on Linux or ordinary BSD? Does any company use it?

Re: Gnu/Hurd strikes back: How to use the legendary OS in a (somewhat) practical way

#264

Post by spookie »

effie wrote: post #262
spookie wrote: post #235

Earlier quoted context omitted.

I'm sorry, as I keep hearing these criticisms around BTRFS, I still don't know why. What is so messy about it? Honest question

It's "perpetually half-finished". Convoluted admin cli tooling, bad track record with reliability and loss of data, lots of stories on the internet. It perhaps got better, but RAID5/RAID6 for metadata (standard use of disks) still not oficially recommended and thus standard RAID5/RAID6 is not reliable. Also, look at some FS benchmarks - BTRFS is still much slower than EXT/XFS, and slower than ZFS. About the only clas…

Thanks, that makes sense. I should look more into it

Re: Gnu/Hurd strikes back: How to use the legendary OS in a (somewhat) practical way

#265

Post by rleigh »

taeric wrote: post #55
darksaints wrote: post #42

Earlier quoted context omitted.

But that is the entire point of the comparison. I get that you think an apples to apples comparison is the most honest way to portray this, but the whole point is to portray that this is an apples to oranges comparison. Linux has millions of lines of code running in ring 0, a micro kernel does not. They may end up having the same lines of code for comparable total system size, but that isn’t the point of the comparis…

Fair. I'm not a fan of apples to oranges comparisons without leaning into more of it. Especially not when the obvious driver for difference between two things is that one is old and has a ton of the code you are currently behind on writing. I do question if process isolation isn't fundamentally hard. Separate processes for separate things entirely is not fundamentally hard. That, I agree. But, so much of what we do i…

QNX managed it! Drivers run in separate address spaces as, does the kernel, making it very robust. It's used for safety-critical applications.

Re: Gnu/Hurd strikes back: How to use the legendary OS in a (somewhat) practical way

#266

Post by effie »

spookie wrote: post #264
effie wrote: post #262

Earlier quoted context omitted.

It's "perpetually half-finished". Convoluted admin cli tooling, bad track record with reliability and loss of data, lots of stories on the internet. It perhaps got better, but RAID5/RAID6 for metadata (standard use of disks) still not oficially recommended and thus standard RAID5/RAID6 is not reliable. Also, look at some FS benchmarks - BTRFS is still much slower than EXT/XFS, and slower than ZFS. About the only clas…

Thanks, that makes sense. I should look more into it

No problem. For more, this looks like a good intro

https://arstechnica.com/gadgets/2021/09/examining-btrfs-linu...

Re: Gnu/Hurd strikes back: How to use the legendary OS in a (somewhat) practical way

#267

Post by yencabulator »

dpe82 wrote: post #59
anon25783 wrote: post #50

Earlier quoted context omitted.

Things are perhaps a bit different now than when Torvalds and Tanenbaum debated the issue on comp.os.minix over thirty years ago.

What, specifically, is different?

1. Read up on the seL4 microkernel. It pretty much destroyed the "microkernels are too slow" argument.

2. Modern day hardware is mostly just ringbuffers mapped to memory. There's a real convergence of hardware interfaces, virtio, and io_uring into all being this very similar looking thing. With IOMMUs, moving drivers to userspace is pretty attractive. There's not much of a difference between a cloud VM getting access to a VFIO device from the hypervisor and a userspace device driver getting access to hardware from the microkernel. And there's a lot of money in making cloud VM networking & storage faster.

Re: Gnu/Hurd strikes back: How to use the legendary OS in a (somewhat) practical way

#268

Post by CRConrad »

prmoustache wrote: post #249
jacquesm wrote: post #73

Once upon a time the Hurd was the future. But that time is long in the past and nowadays the Hurd is a relic and I don't see any chance of a revival. Something entirely new probably stands a better chance at arousing some interest than the Hurd.

Yes we have seen it with projects such as serenityOS, redox but if you look closely at those projects most of them stand upright with just 1 or 2 developers. If for some reason they get burned out or some life changes force them to limit their time and attention to these projects they can fall behind very very quickly. Unless one is already depending on it on a daily basis, nobody wants to take over someone else's pr…

> If for some reason they get burned out or some life changes force them to limit their time and attention to these projects they can fall behind very very quickly.

These projects are all one bus away from becoming the next TempleOS.

Re: Gnu/Hurd strikes back: How to use the legendary OS in a (somewhat) practical way

#269

Post by CRConrad »

davidw wrote: post #116
ssrc wrote: post #62

Earlier quoted context omitted.

I think it's monorepo vs multi-repo, and since Linux maintainers update the drivers (I believe) when internal APIs change, and the internal APIs are not stable, monorepo seems more practical.

There's something clever to say about the author of Linux vs the author of Git, but it's not coming to mind right now...

Both exactly equally famous for sometimes being an asshole?

Re: Gnu/Hurd strikes back: How to use the legendary OS in a (somewhat) practical way

#270

Post by CRConrad »

kjs3 wrote: post #248
dralley wrote: post #118

Earlier quoted context omitted.

I'm not saying it's not an important space, because it is. But the majority of use cases are not that latency-sensitive. And if you're not that latency-sensitive, it's not obvious that microkernels like SeL4 and QNX are faster than Linux, for the relevant definitions of faster. And likely it's not even close when you take into consideration the capability gap between Linux and competitors, that is to say, the "fatnes…

And the goalpost moves again.

Could just as well be read as the position of the goalpost gets more precisely specified for each question. The original "performance" was quite ambiguous; this is just a final specification of what was meant by the word.
Post reply on HN