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MacOS may lose data on APFS-formatted disk images

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21–30 of 193 posts

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

#21
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.)

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

#23

so why exactly does somebody backup into a image with variable size, when they could just dd together a fixed size image that makes these free space calculations unnecessary?

I use a sparse bundle disk image, i.e. a disk image with variable size and consisting of multiple files under the hood, because it is more efficient to back up over a network. Instead of uploading a 50 GB file to a cloud storage on every backup, only a fraction of data has to be uploaded (the sparse bundle’s changed files) which makes backing up the 50 GB file very fast if only a few megabytes were added. If anyone i…

Wait, why would the 50 GB need to be transferred fully every time if it was a fixed size image?

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

#24
post #17

Earlier quoted context omitted.

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.

There was the password vs password hint thing.

Which was a bug in Disk Utility, not APFS.

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

#25
post #3

Click bait. What I describe below applies to APFS sparse disk images only — ordinary APFS volumes (e.g. your SSD startup disk) are not affected by this problem. While the underlying problem here is very serious, this is not likely to be a widespread problem, and will be most applicable to a small subset of backups. Disk images are not used for most backup task activity, they are generally only applicable when making…

You appear to have an agenda of protecting Apple. The title is very clear, and the first paragraph which you quoted explains it in detail. It's significant that an established respected company--the makers of Carbon Copy Cloner--will not support APFS formatted disk images for its backups. While your agenda may be driven by the need to protect Apple, the rest of us need to know this important news about APFS so we can…

This isn't politics.

People can have opinions without them needing to be flagged as having hidden agendas. And I have worked at Apple and can assure you that there isn't some payment structure for posting on forums.

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

#26

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…

The data is probably still there just some metadata being corrupted making it inaccesible to standard tools.

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

#27
post #3

Click bait. What I describe below applies to APFS sparse disk images only — ordinary APFS volumes (e.g. your SSD startup disk) are not affected by this problem. While the underlying problem here is very serious, this is not likely to be a widespread problem, and will be most applicable to a small subset of backups. Disk images are not used for most backup task activity, they are generally only applicable when making…

You appear to have an agenda of protecting Apple. The title is very clear, and the first paragraph which you quoted explains it in detail. It's significant that an established respected company--the makers of Carbon Copy Cloner--will not support APFS formatted disk images for its backups. While your agenda may be driven by the need to protect Apple, the rest of us need to know this important news about APFS so we can…

Carbon Copy Cloner is an excellent program btw - very happy owner here

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

#28

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…

Are you sure the disk wasn't encrypted ?

And given you are running on a Hackintosh there isn't much anyone can do given the unsupported hardware.

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

#29
post #3

Click bait. What I describe below applies to APFS sparse disk images only — ordinary APFS volumes (e.g. your SSD startup disk) are not affected by this problem. While the underlying problem here is very serious, this is not likely to be a widespread problem, and will be most applicable to a small subset of backups. Disk images are not used for most backup task activity, they are generally only applicable when making…

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.

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

#30

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.

Some of the upgrades to High Sierra in my company failed and left the laptop unbootable. Unfortunately, I wasn't involved in the repair so I only have been told it was due to the APFS conversion and that the solution was to wipe and install.
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