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Comment by kbumsik | Hacker News Reader

Two bugs are described in this article:

1. An APFS volume's free space doesn't reflect a smaller amount of free space on the underlying disk

2. The diskimages-helper application doesn't report errors when write requests fail to grow the disk image

These are not even complex problems of the new format. It is just Apple forgot to have basic checks. It is like the root access with an empty password incident happened 2 months ago. Why these serious but basic problems happen? What is going on with Apple?

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(1) is incorrect. Sparsebundles are capable of over-provisioning the storage below them _by design_. They always have been. They are, I believe, APFS snapshots essentially now. This behavior is consistent with most other filesystems with similar constructs.

(2) is the real issue here.

> Sparsebundles are capable of over-provisioning the storage below them _by design_.

According to TFA, HFS+ sparsebundles reflect the limitations of their underlying volume, while APFS sparsebundles do not. Seems clear to me that this is a bug.

Sparse bundle disk images [1] are a more efficient way to store disk images on an underlying file system. They are a completely separate concept from the file system in the disk image itself (besides HFS+ apparently doing some intelligent free space reporting) and are definitely not implemented as APFS snapshots.

[1] https://en.wikipedia.org/wiki/Sparse_image#Sparse_bundle_dis...

This is by far the best explanation of what’s happening at Apple and why we’re noticing these bugs and problems: https://www.imore.com/understanding-apple-scale

Not really.

If you built a new filesystem, competent software engineers will heavily test the corner cases. What happens when the fs runs out of space? What happens when the metadata store runs out of space? etc.

The original article mentions bugs that are pretty obvious cases to test. What precisely happens when you have a sparsebundle that exceeds the storage capacity of the containing volume? A PM needs to define what should happen and an eng needs to test that it does.

It's inexcusable that things like this aren't tested and is an organizational failure. This isn't some complex interaction of earbuds with watch and a cloud system. This is a very testable filesystem.

Agreed. Many of the issues with Apple's software quality lately are fundamentals, not issues of scale. Stuff like this, the root password bug, the many issues with reliability in High Sierra, etc.

These things speak to organizational issues.

File systems are hard. They're incredibly difficult and incredibly important. It look a long time to get to ext4 and NTFS, and there's a reason HFS+ has stuck around for as long as it has, despite all of its shortcomings and limitations.

Even in the Linux work, thinks like btrfs, even though some distros consider it sable, is still treated with scrutiny. Back in the early 2000s, many Linux distros refused to install on XFS or JFS.

Apple's APFS rollout really does fell like it happened way too fast.

Maybe they tested everything and didn't care. That's unlikely but possible.

My guess is more that MacOS just gets the B or C team, and no-one involved was smart enough or diligent enough to think through the implications of sparsebundles that don't reserve space.

Rene Ritchie is very biased. He has to be as his livelihood depends on Apple. I take his words with many grains of salt. The only reason he's quoting Sinofsky is because it gives him a way of excusing Apple's software stumbles of late.

Also, nobody is harder on Apple than the people who know the company best. He’d lose credibility if he pretended everything was all rainbows and unicorns when they clearly are not. He clearly cites how unacceptable some of these bugs are—that’s not being biased.

Like Ritchie, I go back to the days of when the Macintosh Operating System shipped on floppies and didn’t have pre-emptive multitasking or memory protection—everything ran in the same memory space. The entire system would crash pretty regularly due to INIT (system extensions) conflicts, for example.

I can count on one hand the number of times my Mac has kernel panicked over the last few years and I regularly run beta versions of macOS.

So we now measure the reliability of a consumer-grade system on closed hardware by how few times it experiences a kernel panic?

That’s a very low bar. At least Windows has the excuse of having to work with a bazillion drivers.

I am not sure what your point is. If macOS has fewer kernel panics on semi-closed hardware (what laptop/PC hardware is more open these days?) than Windows or Linux on a bazillion drivers, then macOS would be preferable to me if the hardware us acceptable, even if supporting a bazillion drivers is a greater feat.

The point is that Apple provides both OS and drivers for a relatively small set of hardware. In these conditions, the fact that it has kernel panics at all is just Bad. Kernel panics should not happen in 2018, we have the knowledge and the technology to make it happen. It's bad for Windows and Linux as well, but they have the drivers excuse at least - MacOS has no such excuse.

Rene Ritchie is very biased. He has to be as his livelihood depends on Apple.

No, he quoted Sinofsky because he’s one of the few people in the world who understands what it’s like trying to operate at this scale, since he was at Microsoft during it’s heyday.

Corner cases that affect only .01 percent of the installed bases aren’t a big deal when you’re operating at a few million; it’s entirely different when it’s more than a billion devices.

The software issues haven't been corner cases lately. iOS 11 is just... bad software. High sierra has had some rather embarrassing issues too and, I'll say again, they aren't corner cases.

What difference does 1mil vs. 1bil make when they're deploying software on identical hardware? The type security and stability bugs showing in modern macOS and iOS are unacceptable at 100.000 installs. What does volume have to do with accepting empty root passwords?!

> Apple forgot to have basic checks

A common issue with Apple lately.

Glass wall induced forgetfulness? https://thenextweb.com/apple/2018/02/17/apple-employees-keep...

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