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  • macOS, APFS and Time Machine Possibilities

    June 2nd, 2017

    Within days, the wraps will be lifted from the next version of macOS at the WWDC. After little or nothing appeared on the Apple rumor sites, the chatter has increased some in recent days. I’ll avoid most of the suggestions of possible new features, since it’s so close to the real event.

    Except for one thing.

    So at last year’s WWDC, a brand new file system was introduced, the Apple File System (APFS), which would provide more security, more efficiency, better performance, and lots of features that will help protect your data. It’s a good thing, or will be a good thing once the final macOS version is released. The developer’s version was feature crippled, without support for startup disks, Time Machine, FileVault and the Fusion Drive. I assume those problems will be resolved with the next OS release, so regular people can use APFS.

    The iOS version of APFS was deployed to hundreds of millions of Apple customers with the release of iOS 10.3 in March. It appears to have been successful, but consider that there aren’t as many possible storage variations on iPhones and iPads. With more open access to the file system and loads of potential system installation possibilities, potential Mac issues are far more complicated and far more difficult to anticipate. Witness the features that did not, as of last year, work.

    Among the industrial-strength file system features is a Snapshot, which has pointers to data and thus speeds up access. Let’s keep that in mind for a moment.

    Now one of the unsung heroes of the macOS is Time Machine. The vast majority of customers never back up their Macs, and Steve Jobs cited low double-digit figures when Apple’s backup utility was launched in 2007. Time Machine stores incremental backups, which means that many versions of a file, or even files that have been subsequently deleted, are available for fairly quick recovery.

    The original Time Machine took on a sci-fi air as you went back through time to find the file you lost, or to which you wanted to revert. The interface has since been toned down, but this is certainly a useful scheme that allows you to recover one or more files, or, if you’re setting up a new drive or a new Mac, everything you’ve stored on your computer.

    Using Time Machine is really simple. One it’s set up, it will run a full backup (not a clone of your Mac’s startup drive) and then, every hour, store backups of what’s changed. If you set up a backup to a removable drive or memory stick, it will begin the process whenever the drive is mounted. It’s about as easy as it gets, since you don’t have to manually run a backup or schedule one, as you’d do with regular backup software.

    I’ve used it every time I’ve set up a new Mac or recovered the contents of a drive, and it’s really simple to use. Working with Migration Assistant, Time Machine allows you to copy the contents of one Mac or drive to another. It make take a few hours to grab everything, but you’ll soon be up and running essentially as if nothing changed — except for having a new Mac or a new drive of course.

    One thing Time Machine does not do is to allow you to boot from the backup drive. So if your startup drive fails, you would have to restore your data to a new drive before you can get back to work. That’s certainly a severe limitation for the busy person or business. The best solution to that dilemma is to install a dedicated backup app that can create a clone drive; in other words, a mirror of your setup drive. You can use an external drive for the backup, or even a partition, but the latter wouldn’t be a good move. If a drive fails, you’d lose both backups.

    I use Carbon Copy Cloner with an external drive. Another app capable of cloning is SuperDuper, and both will get the job done in exemplary fashion. I run daily backups, when the work day is done. So if something nasty happens to the startup drive, I can get back to work with all of my data mostly intact; at least the stuff that was stored as of the time of the last backup. Time Machine runs on another external drive, and it can help me grab the rest.

    Now the existing version of Time Machine was designed with the current file system, HFS+, in mind, recognizing its limitations. With APFS, Apple builds a new version of Time Machine. Does APFS make it possible to boot from a Time Machine volume?

    I would not presume to guess what changes Apple might make to Time Machine. I suppose it might run the same, except for the changes needed to support APFS. But it may also be that Apple will take good advantage of a modern file system to make it run faster, and do more things.

    As it is, loads of Mac users still don’t backup their data, despite the ease of setting up Time Machine. Maybe Apple will leverage the advantages of APFS to improve the process in a way that will encourage Mac users to get on the backup bandwagon. Even if there are no significant new features, that’ll still be a major advantage.



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    9 Responses to “macOS, APFS and Time Machine Possibilities”

    1. DaveD says:

      I am interested in the current state of Apple File System to be mentioned at the WWDC next week. Since its implementation on iOS went smoothly it would be nice if the macOS experience will be the similar. My backup plan is the usage of Time Machine and the two great third-party apps, SuperDuper! and Carbon Copy Cloner. With disk capacity getting so big, it takes effort to do local backups. One day a multi-terabyte drive will go south. On a side note just recently I had an older USB thumb drive become unreadable and was rescued using another great third-party app, DiskWarrior.

    2. David Schwartz says:

      One thing Time Machine does not do is to allow you to boot from the backup drive

      Yeah it does.

      TimeMachine volumes include the same sparse disk image bundle that the Recovery Partition uses.

      https://support.apple.com/en-us/HT201250

    3. David Schwartz says:

      A comprehensive backup strategy and backup plan can include mirrors and/or clones, but booting into the secondary volume would then require it having _its own_ backup(s), lest the clone drive fails after you’ve made changes to your data.

      There are also usability issues with having other bootable volumes online; if the system boots into the clone inadvertently the user may not notice the difference (since the Desktop background and other queues are the same). Then changes are written to what was supposed to be the backup, and now there is no synchronization anymore. A mess.

      There is always a trade off between time and security (time to backup, time to restore). TimeMachine is drop dead simple, providing security for users who wouldn’t have any backup otherwise. Doing it “right” with third party tools to reduce recovery time is orders of magnitude more complex.

      David
      (late of Dantz Development)

    4. David Schwartz says:

      Undoubtably! But what? When? ¯\_(?)_/¯

    5. dfs says:

      Time Machine is great for backing up single Macs, but should be used for that one purpose only. My experience is that if you try to use it to back up multiple ones (such as by using Time Capsule as a central repository for backup data from two or Macs in the same household), you’re inviting serious trouble. Reason: in this situation Time Machine creates a sparse bundle to store your data, sparse bundles easily liable to corruption, and, as nearly as I could tell when I had this problem, if you have a corrupt one your pretty much s. o. l. since I’ve never found a way to repair one.

      This having been said, if some or all of your data is of any real value to you, backing up to a local volume using Time Capsule or any other method fails to give you adequate protection. There are simply too many scenarios of how both your Mac and your backup volume could be damaged or stolen at the same time. Anything of value also needs remote backing up to iCloud, Dropbox or some similar service. Or even more than one. That may sound paranoid but it’s the way the pros do it, they really like redundancy.

    6. PG says:

      Rumoured Apple Siri speaker will also have capability of time machine.

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