MacOS may lose data on APFS-formatted disk images • Hacker News Board

Re: MacOS may lose data on APFS-formatted disk images

#41

Post by banned1 » Sat, Feb 17, 2018, 10:48 PM UTC

threeseed wrote: post #29

jrochkind1 wrote: post #6

Earlier quoted context omitted.

A lot of people do make backups to disk images though, especially techies. I believe that remains the only method to use 'time machine' with a generic network connected device rather than an apple branded 'time machine' device? The last place you want an unreliable file system is your backups!

Quite a few non-Apple network devices support Time Machine. I back up every day to my Synology NAS for example.

Unrelated (sorry for being opportunistic):

How do you like your Synology NAS? I’m considering it.

Re: MacOS may lose data on APFS-formatted disk images

#42

Post by tlo » Sat, Feb 17, 2018, 10:51 PM UTC

My AFPS volume got corrupted probably during the upgrade to High Sierra. No data lost, but my disk is missing almost half the disk space. See https://apple.stackexchange.com/q/311843/26185

Re: MacOS may lose data on APFS-formatted disk images

#43

Post by derefr » Sat, Feb 17, 2018, 10:52 PM UTC

wiradikusuma wrote: post #20

I upgraded my hackintosh to High Sierra with APFS. The next day, I accidentally switched off the machine while it was in the _process_ of shutting down (the screen had gone blank, but casing still emitting lights). Next time I turned it on, I couldn't get past login screen (giving me forever beach ball). I put the ssd inside my old MBP as slave to recover data. The ssd was corrupted, most data gone, as in shown in Fi…

Hypothesis: since it does _get to_ the login screen, the OS does think that the disk is in a consistent state.

Maybe your unclean shutdown forced the async conversion from HFS+ to APFS to become forced-synchronous? Try leaving the drive in the Hackintosh machine, spinning at the login screen, for a few hours. Maybe it’ll “finish.”

Re: MacOS may lose data on APFS-formatted disk images

#44

Post by protomyth » Sat, Feb 17, 2018, 10:54 PM UTC

FreakyT wrote: post #21

notadoc wrote: post #13

High Sierra seems like a real gem.

Honestly, it's the first Mac OS release I'd actively recommend avoiding upgrading to. It offers essentially no benefits over the prior release, and a whole lot of downsides. (Security issues notwithstanding, High Sierra also drops compatibility for a lot of older software.)

Lion actively screwed up normal people's workflows with the botched "Save As" replacement. I still want an explanation of why they thought that was a good idea. We skipped that one after one of the admin assistants discovered the new joy.

The whole California-series of OS has had a broken Finder. I see some fixes in High Sierra, but its still buggy as heck for large file moves and broken scripting. I'm hoping they take a long hard look at Mac OS like they seem to be with the next iOS. I can forgive removing some UNIX commands, but the general bugs and unexplained crashes are starting to get on my nerves.

Re: MacOS may lose data on APFS-formatted disk images

#45

Post by hitekker » Sat, Feb 17, 2018, 10:54 PM UTC

Yet another reason to stick with El Capitan.

Re: MacOS may lose data on APFS-formatted disk images

#46

Post by StillBored » Sat, Feb 17, 2018, 10:55 PM UTC

toasterlovin wrote: post #16

torstenvl wrote: post #9

Yes, fairly limited impact, but still. Data loss is fucking important. We aren't talking about an occasional stutter when moving windows or a sound driver that sometimes needs a reboot to resume working. This is a major bug. I would really really like it if Apple would get their shit together so that people who actually rely on their computers to work correctly can upgrade at some point.

As a counterpoint, APFS was deployed to almost a billion devices over the span of several months when it was release and, IIRC, this is the first major issue.

How do you know that? Filesystem corruption is frequently silent, and every-time it happens customers don't get on the phone and send the disks to apple so that they can root cause the problem. Its quite possible this bug has happened an untold number of times before it happened to someone who went through the effort to reproduce and isolate it.

Re: MacOS may lose data on APFS-formatted disk images

#47

Post by rangibaby » Sat, Feb 17, 2018, 11:06 PM UTC

tlo wrote: post #42

My AFPS volume got corrupted probably during the upgrade to High Sierra. No data lost, but my disk is missing almost half the disk space. See https://apple.stackexchange.com/q/311843/26185

I “lost” a lot of space due to time machine local backups. It was frustrating to research and I thought there was something seriously wrong with my computer. Try deleting the local backups and see if you get some space back

Re: MacOS may lose data on APFS-formatted disk images

#48

Post by eropple » Sat, Feb 17, 2018, 11:08 PM UTC

derefr wrote: post #39

I tend to create sparsebundles to clone my git repos within, to get around the overhead of having huge numbers of inodes on a volume. (Copying, deleting, unpacking archives, Spotlight indexing—all are way slower when you have the worktrees and .git directories from a thousand large repos splayed out across your disk.) So I was a little worried here. Thankfully, I had manually been setting my sparsebundles back to HFS…

This is a neat idea, I've never thought about doing that. You should write a blog post about it.

Re: MacOS may lose data on APFS-formatted disk images

#49

Post by tankenmate » Sat, Feb 17, 2018, 11:13 PM UTC

wiradikusuma wrote: post #20

I upgraded my hackintosh to High Sierra with APFS. The next day, I accidentally switched off the machine while it was in the _process_ of shutting down (the screen had gone blank, but casing still emitting lights). Next time I turned it on, I couldn't get past login screen (giving me forever beach ball). I put the ssd inside my old MBP as slave to recover data. The ssd was corrupted, most data gone, as in shown in Fi…

Wow, almost sounds like the two step commit isn't working properly for APFS.

Re: MacOS may lose data on APFS-formatted disk images

#50

Post by huslage » Sat, Feb 17, 2018, 11:14 PM UTC

kbumsik wrote: post #40

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 m…

(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.