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

#181

Post by xondono » Tue, Nov 02, 2021, 6:42 PM UTC

mywittyname wrote: post #155

xondono wrote: post #109

I get that for people from IT it sounds surprising, but from a hardware perspective I would say it’s a good change. Instead of having a SPI flash memory with the firmware they’ve gone ahead and merged that into a single flash memory. It’s weird because we are used to see disks as independent modules, but for these devices that’s simply a useless distinction, something that we keep for legacy reasons, not because it p…

Being able to swap disks is a meaningful advantage. After all, it's the part most likely to fail first, and often first limitation people hit on a machine. Storage tech is still advancing at a decent clip. In 5 years, there will probably be 4-6TB drives on the market with 2-4x the throughput for the same price as 1TB drives today.

But that’s another different battle, and has nothing to do with this change. Disks were already soldered down, and that’s a tradeoff.

I get that for some people swappable disks are great, but those people couldn’t really use pre-M1 macs. The only change is that instead of two different interfaces for non volatile storage, now there’s one.

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

#182

Post by azalemeth » Tue, Nov 02, 2021, 6:43 PM UTC

wtallis wrote: post #110

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…

In practice, exhausting NAND write endurance is usually not what causes SSDs to fail in the field. It is especially unlikely to be the underlying cause of unexpected and seemingly premature catastrophic SSD failure. Also, it is not possible for an SSD to decrease your usable storage space over time. That would break any partition table format or filesystem that expects an ordinary block device. It also wouldn't win y…

> It is especially unlikely to be the underlying cause of unexpected and seemingly premature catastrophic SSD failure.

One of my graduate students experienced this, the hard way: writing up his thesis, his mum plugged in "the wrong USB C" charger. I don't know exactly what happened, but the board was utterly fried. The problem with the soldered-to-the-motherboard, everything-utterly-encrypted approach is that it's almost impossible to do data recovery. On the M1+ models, you literally can't do anything except semi-fix the motherboard as the flash and its controllers are integrated and the keys are cryptographically securely stored. This video [1] shows what data recovery is really like -- I don't often link to YT videos, but it is an hour long, involves an awful lot of BGA de-balling and re-balling and the scouring of spare chips from other donor dead machines, as Apple doesn't let manufacturers sell the chips separately and datasheets are all NDA'd.

We're very much in the part of the curve where you'd need a lab and a lot of serious work to get data off these things without either sacrificial macs or luck (e.g. one blow voltage regulator). Of course, the flip side of this is that your data is really, really secure. You just have to be damn sure that you back it up correctly.

[1] https://www.youtube.com/watch?v=110x5rMHCIw

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

#183

Post by lamontcg » Tue, Nov 02, 2021, 6:43 PM UTC

codetrotter wrote: post #177

lamontcg wrote: post #139

Earlier quoted context omitted.

> The SSD is reasonably considered to last the "lifetime" of the product Except for simply running of out drive space. So if you want to buy something and have it last 5+ years you need to spec it out from the start to have way more drive space than you think you'll ever use. Or else when it runs out and you really need that extra space you're forced to upgrade everything in order to get the extra space since you mad…

> Except for simply running of out drive space. > So if you want to buy something and have it last 5+ years you need to spec it out from the start to have way more drive space than you think you'll ever use. Yup. When I bought my MBP M1 2020, I foolishly went with 256GB of storage. Installed Xcode and that was like 15GB of available storage space gone right then and there. The simulators take another few GB on top of…

Yeah I just ordered a 16" MBP M1 and my math was that I routinely run with about 1TB of storage with a lot of fussiness, I would have ordered 2TB, but since it isn't upgradeable I ordered 4TB.

That made someone's numbers at apple like $400 better at least.

And it would probably be better for me financially to wait 4-5 years until I really needed 4TB before upgrading (if I ever needed to, which I might not).

Same thing with RAM. 16GB is proving to simply not be quite enough, so I would have gone with 32GB, but instead I went for 64GB for future-proofing.

I'd much rather have bought 32GB now, and then upgraded to 64GB maybe multiple years down the road when I needed it.

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

#184

Post by filmgirlcw » Tue, Nov 02, 2021, 6:45 PM UTC

ApolloRising wrote: post #148

1123581321 wrote: post #96

Earlier quoted context omitted.

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.

Video editors have workloads that can write a ton for each project in 4k and 8k resolutions, if its pro res even more. First thing they do is grab the largest fastest storage they can work off externally.

Right -- but work externally is key here. Sure, you often have some stuff you'll do locally, but having external disk arrays is the name of the game if you're doing large volumes of video, not just because you want to be able to have a backup if your internal dies, but because lots of other people often touch your stuff and it just fits a workflow better to use fast networked storage when possible.

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

#185

Post by nsxwolf » Tue, Nov 02, 2021, 6:46 PM UTC

Is this also why you can’t install Monterey on a non-Apple SSD? I haven’t seen an article acknowledging this problem but others are experiencing it in various forums.

My 2013 Mac Pro had an SSD failure so I replaced it with a standard M.2 drive and an adapter. Can’t upgrade.

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

#186

Post by bastardoperator » Tue, Nov 02, 2021, 6:46 PM UTC

aeturnum wrote: post #116

justin_oaks wrote: post #90

Earlier quoted context omitted.

Do you have a threshold for this? I assume that if your laptop wasn't working and all you had to do was take a single screw out then you'd do it, rather than taking it to a repair shop or buy another. Or if the repair cost was extreme, but it was relatively easy to fix it yourself. Your point of view is valid of course. At the same time I believe many people don't have sufficient money to allow them the luxury of nev…

There's the old joke about a plumber to charges $100 to fix a hot water heater by hitting it once with a hammer. The home owner, incensed by such a bill for a simple action, demands the plumber justify it. The breakdown is: $1 hammer strike, $99 choosing correct location. Even a decade ago, the rewards for being able to repair computers were pretty substantial. Your computer was likely to have routine failures and yo…

Exactly this. The amount of time, effort, labor, sourcing tools, parts, coupled with education, or making a costly mistake, etc... The warranty or repair person is actually cheaper if you're able to put a price on your time. They also do better work in most cases.

I just leave it to the professionals because it saves me money/time. I have no doubts I could do my own repair but from this vantage point it's just not a sound investment.

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

#187

Post by aneutron » Tue, Nov 02, 2021, 6:47 PM UTC

slownews45 wrote: post #156

aneutron wrote: post #118

I get that the memory bandwidth and performance of the SoC is intimately tied to the CPU, GPU and memory being on the same silicon (grossly vulgarizing the approach). However, there is no reasonable justification (as far as I can tell) for why the SSD would have to be soldered onto the same SoC, and even less reasonable justification for why the iBoot stuff couldn't be located on an EEPROM or something of the sort, l…

Does anyone laugh a bit at these types of comments? Using these "stupid" and "unjustifiable" approaches, apple has delivered highly reliable / fast machines to lots of users. They come with applecare if you want, which gets you walk in fix/replace at their stores. Note, they've already don't this on iphones - millions shipped. They are going for as much reliability / speed out of this for the 90%+ of users who are no…

You are arguing without any arguments.

1) I agree that some integration is intimately tied to how well the machines performs. I also referenced this in my comment. What I don't agree to is the SSD being soldered on. It uses the same PCIe lanes it would use if it was swappable ! As for the "stupid" approach, it really doesn't make much sense to tie the capability of the machine FUNCTIONING to a storage that you cannot change (and that is bound to break eventually from wear & tear, because it's an SSD).

2) The iPhone are a different story. It's a different requirement all together. You have to fit EVERYTHING in a couple of mm2 of surface. That's a very tough requirement, and everyone understands that you can't have the ability of swapping an SSD and having the portability that the iPhone offers at the same time. The same is simply not true for a professional laptop.

3) I sincerely don't see how an iBoot-inspired design would replace UEFI anytime soon. The latter is more powerful as far as I can tell (please correct me if I'm wrong).

4) The "support" plan you're describing is in my eyes extortion. If I can buy an SSD for 100€ on Amazon, and replace it down the line 5 years from now, it really doesn't compare to paying 200€ / year for an insurance, when all it covers is bringing your laptop to its original state. A swappable SSD can be expanded down the line when storage gets denser / cheaper.

All-in-all, I do agree and fully support a degree of integration that's backed by technical motives (i.e. Otherwise unattainable performance), but when the motives start turning into more lock-in and sell-up motives, that's where my support ends.

I genuinely do not understand how you could view this as a "good" thing. As for the 90% users who are not going to manually swap out SSDs, it would still be the same ! They won't have to touch them !

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

#188

Post by filmgirlcw » Tue, Nov 02, 2021, 6:49 PM UTC

lamontcg wrote: post #139

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…

> The SSD is reasonably considered to last the "lifetime" of the product Except for simply running of out drive space. So if you want to buy something and have it last 5+ years you need to spec it out from the start to have way more drive space than you think you'll ever use. Or else when it runs out and you really need that extra space you're forced to upgrade everything in order to get the extra space since you mad…

Yup. I just got a M1 Max with the 32-core GPU, 64GB of RAM, etc. The only area I cheaped out, relatively speaking, was with storage. Where I kept it at 1TB. I sort of regret this now (despite having a 2TB SSD in my iMac, a 2TB SSD in my gaming PC, several 1TB external SSDs, and a NAS with 24TB all in my home), but after spending over $4300 with tax/Apple Care, I just couldn't stomach a $400 upsell. But I spent $4300 in the hopes that this will be a five year laptop. I think I'll be fine as far as storage goes, since so much of what I do is on clouds anyway, but I am already having minor "what if" pangs, since I can't upgrade the SSD.

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

#189

Post by wtallis » Tue, Nov 02, 2021, 6:52 PM UTC

KennyBlanken wrote: post #170

1123581321 wrote: post #96

Earlier quoted context omitted.

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 a…

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

It only takes a bit of arithmetic to prove that this cannot possibly be true, or else all of those 95%-full drives would have long since failed, and QLC SSDs would have been a disaster and never would have been adopted by system OEMs that provide multi-year warranties. (And if it were true, then SSDs prior to TRIM wouldn't have been viable.)

You can include static data in wear leveling, and all SSDs do. It does lead to some write amplification, but that's already factored in to a drive's endurance specs.

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

#190

Post by mschuster91 » Tue, Nov 02, 2021, 6:56 PM UTC

azalemeth wrote: post #182

wtallis wrote: post #110

Earlier quoted context omitted.

In practice, exhausting NAND write endurance is usually not what causes SSDs to fail in the field. It is especially unlikely to be the underlying cause of unexpected and seemingly premature catastrophic SSD failure. Also, it is not possible for an SSD to decrease your usable storage space over time. That would break any partition table format or filesystem that expects an ordinary block device. It also wouldn't win y…

> It is especially unlikely to be the underlying cause of unexpected and seemingly premature catastrophic SSD failure. One of my graduate students experienced this, the hard way: writing up his thesis, his mum plugged in "the wrong USB C" charger. I don't know exactly what happened, but the board was utterly fried. The problem with the soldered-to-the-motherboard, everything-utterly-encrypted approach is that it's al…

> You just have to be damn sure that you back it up correctly.

Most somewhat serious NAS appliances offer being a TimeMachine server which is more than enough for most people.