Apple Silicon Macs can't boot from external drive if internal drive failed • Hacker News Board

Re: Apple Silicon Macs can't boot from external drive if internal drive failed

#161

Post by GhettoComputers » Tue, Nov 02, 2021, 6:21 PM UTC

pvarangot wrote: post #114

Vogtinator wrote: post #63

Earlier quoted context omitted.

It's not just about upgrades, in fact it's not even mainly about upgrades. It's about being able to understand the machine, repairing it when necessary and ultimately being able to rely on it. Otherwise your device might be a candidate for the bin after the warranty expired, which can be surprisingly quick.

> a candidate for the bin after the warranty expired, which can be surprisingly quick All my all Macs sold for great value after I was done with them or got a better one, even with an expired guarantee. It took like a week or two to sell them. I'm still stuck with Thinkpads because the used market is shit. My last Thinkpad I got kinda impulsively as a workstation for Ableton is my deepest regret. It was a year ago, t…

Which one did you get?

Re: Apple Silicon Macs can't boot from external drive if internal drive failed

#162

Post by webmobdev » Tue, Nov 02, 2021, 6:23 PM UTC

ChuckNorris89 wrote: post #76

liminalsunset wrote: post #26

General grumpiness about this particular design decision aside, it appears that since the T2 Macs, the main SSD was being used to store core system firmware. On T2 I think it's BridgeOS that sends the EFI image to the Intel side to boot it, and it does the firmware verification and loading. This setup has a benefit; namely, it is now impossible to brick the system with a bad BIOS/EFI flash, and you'll never need to u…

>whatever failure damaged the SSD is statistically likely to compromise the reliability of the rest of the board Sorry, but how? That's just reads like BS. SSDs have limited lifespans due to the limited write cycles of the NAND chips. So no, what damages NAND does not damage the rest of the board. The more you write and swap to flash, the faster it wears out, taking your Macbook down with it when it dies. Granted, I…

> That's just reads like BS.

Because it partly is. It's just a lame defence / justification of soldering SSD, RAM and other parts, the major advantage of which is to make modern electronics more complex, hard to repair and prevent upgrades (i.e. "planned obsolescence"). If SSDs were reliable beyond 5+ years, manufacturers would be highlighting that and even offering guarantees for such a period. (Hell, most RAM today come with "lifetime" guarantees, even though RAM modules too fail occasionally).

The modular design for computer hardware was chosen for a practical reason - that hardware can, and do fail. While electronic manufacturing has advanced a lot, minimizing failure rates to a great extent, the pros of replaceable modules absolutely still outweigh any of the alternative hardware designs so far.

Re: Apple Silicon Macs can't boot from external drive if internal drive failed

#163

Post by floatingatoll » Tue, Nov 02, 2021, 6:23 PM UTC

KennyBlanken wrote: post #143

Dylan16807 wrote: post #115

Earlier quoted context omitted.

How many SSDs have you worn out? I've never managed it.

Apple SSD module failures on portable Macs are quite common. A buddy has a computer repair shop and they do brisk business replacing them. Mine failed about 5 years in. SSDs are wear items. Especially when they're quite full, it is very easy to blow through spare writes and brick the drive.

Did those modules fail readonly, and the SMART data showed that their write limit had been reached?

Or did the entire module electronically fail, as distinct from the SSD "no more writes" case?

Re: Apple Silicon Macs can't boot from external drive if internal drive failed

#164

Post by bogantech » Tue, Nov 02, 2021, 6:24 PM UTC

liminalsunset wrote: post #26

General grumpiness about this particular design decision aside, it appears that since the T2 Macs, the main SSD was being used to store core system firmware. On T2 I think it's BridgeOS that sends the EFI image to the Intel side to boot it, and it does the firmware verification and loading. This setup has a benefit; namely, it is now impossible to brick the system with a bad BIOS/EFI flash, and you'll never need to u…

> This setup has a benefit; namely, it is now impossible to brick the system with a bad BIOS/EFI flash, and you'll never need to use a hardware SPI flasher to recover.

T2 could have been designed to store / recover the rom in an SPI flash too. It's just cheaper to store it on the SSD

Re: Apple Silicon Macs can't boot from external drive if internal drive failed

#165

Post by floatingatoll » Tue, Nov 02, 2021, 6:24 PM UTC

DemiGuru wrote: post #49

tyingq wrote: post #41

Earlier quoted context omitted.

Though who knows what types of experimentation, trial and error SuperDuper went through to make it work.

I know that David Nanian and co worked with Apple to address the issue(s) that prevented them from providing a bootable backup.

The ability to create bootable backups on external drives as you describe, does not necessarily conflict with the inability to boot from external drives as the post link describes.

Re: Apple Silicon Macs can't boot from external drive if internal drive failed

#166

Post by handrous » Tue, Nov 02, 2021, 6:25 PM UTC

nyxaiur wrote: post #75

aluminussoma wrote: post #23

Earlier quoted context omitted.

I suspect they began soldering it because the cable connecting the disk drive had a lot of problems in older MacBooks. Soldering may have been an easy fix for that. I hate the soldering, too. I'm just offering an explanation that may make some sense given the context.

pcie and nvme ssds use ports that are similar to ram slots there is no more cable involved.

It's less the cable than the connector, so, similar trouble with nvme ports (and ram slots, for that matter). I've barely had exposure to supporting laptop hardware, and have seen "thing shimmied loose" or "contact corroded" as the root cause of problems more than once.

Re: Apple Silicon Macs can't boot from external drive if internal drive failed

#167

Post by fsflover » Tue, Nov 02, 2021, 6:27 PM UTC

Milner08 wrote: post #15

gameswithgo wrote: post #7

Consider options like Framework laptops that let you actually own your hardware, and repair it.

If only they were available in the UK

Perhaps you can consider this one instead: https://puri.sm/products/librem-14.

Re: Apple Silicon Macs can't boot from external drive if internal drive failed

#168

Post by jbverschoor » Tue, Nov 02, 2021, 6:28 PM UTC

KennyBlanken wrote: post #143

Dylan16807 wrote: post #115

Earlier quoted context omitted.

How many SSDs have you worn out? I've never managed it.

Apple SSD module failures on portable Macs are quite common. A buddy has a computer repair shop and they do brisk business replacing them. Mine failed about 5 years in. SSDs are wear items. Especially when they're quite full, it is very easy to blow through spare writes and brick the drive.

There was a problem with some of the SSDs where they corrupt themselves on powerloss.

That’s a totally different reason, and afaik, they should be using proper caps to let the controller write/flush their buffers.

My last MacBook Pro was 7 years old, almost always full, and still works fine. Granted I’m not a video editor, but I had quite some write cycles.

Re: Apple Silicon Macs can't boot from external drive if internal drive failed

#169

Post by fsflover » Tue, Nov 02, 2021, 6:30 PM UTC

lotsofpulp wrote: post #127

MangoCoffee wrote: post #99

Earlier quoted context omitted.

I don't want to repair my laptop either but I want to upgrade my laptop a year or two down the line. The modern laptop can go much further with a simple upgrade like RAM or SSD HD. Apple's laptop is really limited in this way. The older generation of Apple's laptop allowed you to upgrade RAM and HD.

Apple is targeting the population that has no need for upgrades. Watching videos, browsing internet, sharing pictures and videos, video calling and basic spreadsheet/word processing needs no upgrades. I use a 2015 MacBook Air and I don’t need an upgrade, and I probably do more on my laptop than 80% of people.

> Apple is targeting the population that has no need for upgrades.

And also those who very frequently do backups, because restoring the data from a failed SSD would be problematic.

Re: Apple Silicon Macs can't boot from external drive if internal drive failed

#170

Post by KennyBlanken » Tue, Nov 02, 2021, 6:31 PM UTC

1123581321 wrote: post #96

ChuckNorris89 wrote: post #76

Earlier quoted context omitted.

>whatever failure damaged the SSD is statistically likely to compromise the reliability of the rest of the board Sorry, but how? That's just reads like BS. SSDs have limited lifespans due to the limited write cycles of the NAND chips. So no, what damages NAND does not damage the rest of the board. The more you write and swap to flash, the faster it wears out, taking your Macbook down with it when it dies. Granted, I…

I think you are using old information. Any modern SSD should be good for a few hundred to several hundred TB and may reach a PB. It would be very hard to use a personal computer that heavily. Most people would take 20 years or more.

That's not how SSD wear works because nobody completely writes to their SSD, erases it, and writes again.

You can't wear-level against blocks that are in use, only blocks that are free.

If every person I've helped socially and professionally is any indication, people keep their storage anywhere between 80% and 95% full.

At 95% full, all your write cycles are focused on just 5% (plus spare provisioned blocks.)

Think about how browsers consume all available memory and then readily push the system into using a lot of swap. I have to restart my browser regularly because of how much ram it uses even if I've closed every tab.

Think about how whole-system file content indexing is the norm, and all the write operations that occur every time a file is added or updated.

Think about how a lot of applications are just electron apps and they routinely update themselves.

Think about all the filesystem metadata changes.

Etc.