I have an old MBP which works fine right now. I have no immediate plans to change it.

But it is getting old, the discrete GPU died, and I expect it could die at any time. I would like to keep my option open to move to a Linux laptop when this machine dies. Most of the software I use is either open source or runs on Linux as well and I rely heavily on Terminal/bash already. Considering that and not wanting to be tied to macOS due to not having a solid cross-platform backup, here's my current backup strategy to allow either a Mac or linux based OS to be my next computer for my current data.

modified backups

  • keep frequent backups, but, rather than relying only on Time Machine, backup /Users/ via rsync as well. (what file system is my best bet here?)

  • run preliminary trials on restoring the rsync backups into a test Linux VM.

As you an see - I'm not decided what filesystem I should use to rsync as Time Machine backs up to HFS+ and since I haven't picked a Linux it's not clear if I want / can mount HFS+ to read the backup data.

What setup allows me to restore my data that is backed up with rsync to any Linux?

  • I would support reopening this if two main points were cleared up. Make this about now - how to move your files now is best. A year down the road, it still can get current answers if today’s answer changes. First problem is reading a backup unless you want to be ok borrowing a Mac to load your current backup and then migrate to a specific version of a specific OS. Leaving this three part (apps and files and backups) and leaving the ultimate OS so vague makes this super broad as written on the first draft.
    – bmike
    Commented Jul 9, 2018 at 23:51
  • rsync would be the part that allows me to move to Linux. Why would I need to borrow a mac? The real outstanding question there is the file system. And, no, this is not about moving the files now. If the question stays on hold, so be it - plenty of people don't get a new computer before their old computer dies - they plan to restore from backups. That's what I am planning for here.
    – JL Peyret
    Commented Jul 10, 2018 at 0:33
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    I honestly and sincerely don't see why this such a complex issue. The answer is simple: store your data in the cloud. Ok...so cloud is primary syncing and is not a backup per se. Then hybrid cloud use a NAS with backup built in and cloud sync capability.
    – Allan
    Commented Jul 10, 2018 at 2:20
  • Perfect - I don't think anyone's going to pick a fight as to why you want to remain open to restoring data to linux, so I've edited out a lot of the process / how you came to want a cross platform backup.
    – bmike
    Commented Jul 10, 2018 at 10:50
  • Actually, this is an extremely difficult question, as my looong answer below, may make clear. Apple in no way shape or form wants to make it easy to escape their grasp. As for @Allan 's comment, I suggest you consider how Apple modified NFS (AppleDouble) & SMB (Alternate Data Streams) to see how convoluted it gets when trying to use a NAS. The cloud will not help. The question is, what extended attributes, forks, & other metadata are retained when restoring.
    – Diagon
    Commented Jun 1, 2020 at 11:19

3 Answers 3


Use the cloud to store your data.

I actively use three different operating systems: macOS, Windows, and BSD (I do use Linux from time to time, but generally avoid it). To access my data on each of these platforms, I use the cloud (a hybrid cloud to be exact).

This can be as simple as having a OneDrive, DropBox, etc. account and a simple USB external drive to back up your data to a highly integrated hybrid cloud consisting of cloud storage, a local NAS with it's own cloud sync clients and external backup.

The point is: separate your data from your "operations." In other words, become platform agnostic. Because, when you structure your data this way, regardless of what you move to, your data will be ready.

Simple Cloud

If you were to use OneDrive or DropBox, for example, you could store all of your documents to the cloud. Both have clients for macOS and Linux so both could sync with no issue.

As for backups, both have native backup software (i.e. Time Machine) that allow you to efficiently back up your machine and data to an external USB or NAS device.

Hybrid Cloud

I am a huge fan of Synology NAS devices. I store my data on cloud services (like OneDrive) and sync it via Synology's cloud sync software back to my Synology. My Mac (and my Windows and BSD machines) all have external USB drives for backup and my NAS has it's own external drive(s) for backup (I have two).

Is it overkill? Probably. However, I haven't lost data in over 15 years (I was doing this before cloud storage came out strictly with NAS - nfs, smb, afp, etc.)

Some notes

  • I use utilities like KeePass's (cross platform password database) data file on the cloud so all of my apps can access it from any device from anywhere

  • I use local incremental or snapshot backups so I can easily restore data should I type the incorrect rm command.

  • I keep my data and backups in multiple places - it's in the cloud, it's synced to three machines (where applicable) which are locally backed up, it's synced to a NAS which itself is locally backed up.

  • I back up my "settings" (i.e. .bash_profile, ./ssh/config, ./ssh/authorizedkeys etc.) the cloud.


Efficient use of cloud services and/or technologies will enable you to store you data in a centralized location making migration from one platform to another quite simple.

  • I like the Synology suggestion, those are essentially Linux boxes and can have rsync turned on (there is a way to do that in the box's web portal). That would give you an uncomplicated way of keeping a synced copy of your home folder on a machine that maintains the data's original format and layout and is now on a non-Mac file system. An alternative would be to get ahold of some cheap desktop machine that you can put linux on and then setup rsync on the command line yourself. Commented Aug 8, 2018 at 19:51
  • @DavidRouse - the rsync question is much more complicated than this. Apple had to modify it to recognize the complicated forks, extended attributes & other metadata in their FS's. (Similarly with tar.) So Apple's rsync will only be able to save to another Apple disk. There is an alternative, rsync+hfsmode that used the AppleDouble format and which you can see discussed in my answer, below. Also, check my comment in the OP about Apple's modification of NFS and SMB.
    – Diagon
    Commented Jun 1, 2020 at 11:24

One approach would be to keep on using Time Machine and defer the decision till the mac dies.

  1. Purchase a new mac from Apple. Keep all packaging.

  2. Restore from Time Machine backup (very simple).

  3. Evaluate the replacement mac (or not, if you've already made up your mind)

  4. If you decide to migrate to Linux, just copy your user files to your target Linux system.

  5. Return mac to Apple. You have up to 14 days from purchase (double-check that in your country) to return it, no questions asked. Apple is extremely good with this, I've done it before, though not for this reason. 14 days is more than enough to do this, if you can get hold of a Linux system soon enough.

  • 1
    It's the file copying bit that is the problem. Apple uses a convoluted filesystem format, that includes metadata and forks that linux does not use. If you're interested, have a look at my answer.
    – Diagon
    Commented Jun 1, 2020 at 11:29

There are three problems you're dealing with here:

  1. How do you back up your Mac filesystem in such a way that you don't lose any data?

  2. How do you make that data accessible to linux?

  3. How do you use that data in linux?

None of these are immediate when operating between the Apple ecosystem and any other (Windows or Linux).

The reason for these difficulties is that Apple's filesystems, in order of historical introduction, HFS, HFS+ and APFS, are filesystems that use "Extended Attributes" (EA's), which include "forks."

These metadata components may not be translatable in any obvious way to another filesystem. For example, Apple FS's have as standard, two forks (though they may technically have any number). The data fork contains most of what we usually think of of file data, along with a resource fork, often but not solely used by executables. (And though that wikipedia link does not mention the resource fork in APFS, they do still exit there.) There is other metadata, including that for the Finder program and "a separate area for metadata distinct from either the data or resource fork... However, the amount of data stored here is minimal, being just the creation and modification timestamps, the file type and creator codes, fork lengths, and the file name."1

An Approach that Puts Off Part of the Problem by Backing up to an Apple Formatted Disk

One approach is to backup your present files using some Mac solution that will keep copies of your files on an HFS+ or APFS filesystem. When the time comes to move to linux, you will have your files and be able to read them (though not write) using linux's hfsutils, hfsprogs and hfsplus or, apfs-fuse(installation tutorial), apfsprogs-git & linux-apfs-dkms-git.

Make sure that your backup system does not store your files in some proprietary archive format that you will not be able to read under linux, which may happen if you are not using a cross-platform tool. For-fee solutions include Get Backup Pro and CronoSync Express. While the first would be a true backup (keeping historical copies of files), the second could be either a backup or a simple mirror. It is possible that TimeMachine might also work, though you will have to confirm that it doesn't use an archive format unreadable under linux. You just want an APFS filesystem, with you files copied to it.

Later You Will Want to Use Your Files on Linux

Of course, for the purposes of your question you will in addition want to know how to represent all of your files in a usable way on some linux filesystem. Clearly the Finder data is of no use, and you will have to lose HFS+'s "birthtime" attribute (see below), because that is not tracked in Linux. The data fork contains the bulk of the information, but what relevance the resource fork and some of the other metadata may have, will depend on the file. How problematic this may become for you, may not be clear until you try.

The following approaches will allow you to save all of your MacOS data instead to a linux formatted disk, thereby doing without Mac backup software or TimeMachine, etc., and also dispensing with the later need to read an Apple disk under linux; though you will still then be faced with the question of proper use of that data under linux. You may do well to consider this article, "Command Line Backup Solutions on Mac OS X," before proceeding. As discussed in that article, be careful to note that using MacOS's resource fork aware version of rsync (or tar) will produce output that is not usable by linux's version or rsync or tar!

Backing up to a linux disk with rsync

There is a project called rsync+hfsmode that will handle backing up to linux formatted disks properly, at least for HFS+, but it does it by creating two files on the backup drive: filename, containing the data fork, and ._filename containing the resource fork and Finder metadata. Furthermore, when copying back to an HFS+ disk, a second step is needed to reconstitute those two files into a proper HFS+ data structure. You can see a more complete discussion at the project page. The filename/._filename system for storing HFS+/APFS files to other filesystems, has a name. It is called AppleDouble format. I am not clear if this same approach will work for APFS, though the question asked on the Apple Developer Forum was responded to with silence; so perhaps not.

Backing up to any kind of disk with dar

Disk Archiver (dar), which is cross-platform and available in Homebrew, can handle the unique characteristics of MacOS filesystems (they do not distinguish between HFS+ and APFS, but say they can handle extended attributes, including file forks). According to their Features page:

EXTENDED ATTRIBUTES (EA) references: MacOS X FILE FORKS / ACL Dar is able to save and restore EA, all or just those matching a given pattern.

File Forks (MacOS X) are implemented over EA as well as Linux's ACL, they are thus transparently saved, tested, compared and restored by dar. Note that ACL under MacOS seem to not rely on EA, thus while they are marginally used they are ignored by dar.

FILESYSTEM SPECIFIC ATTRIBUTES (FSA) references: MacOSX/FreeBSD Birthdate, Linux FS attributes

Since release 2.5.0 dar is able to take care of filesystem specific attributes. Those are grouped by family strongly linked to the filesystem they have been read from, but perpendicularly each FSA is designated also by a function. This way it is possible to translate FSA from a filesystem into another filesystem when there is a equivalency in role.

currently two families are present: HFS+ family contains only one function : the birthtime. In addition to ctime, mtime and atime, dar can backup, compare and restore all four dates of a given inode (well, ctime is not possible to restore)

I also had some discussion on these issues with the developer.

Since dar is cross-platform, you don't have to worry about the format it stores the files in, since you'll also be able to install dar on linux, when it is time to move there. In this case it probably makes sense to format your backup disk as some linux filesystem. You could use APFS if you wanted, as it's also readable under linux, but that seems pointless.

Restoring to a linux disk will produce error messages when metadata can not be reproduced. You will be able to save the problematic files in a smaller archive. Whether you can explore the attributes of those failing files using linux tools, I am not yet clear.

Backing up to Any Kind of Disk Using Restic

Restic is similarly cross-platform and available in Homebreaw, and can handle Apple disks. (Though again, they do not distinguish HFS+ from APFS.) There is a detailed bug report describing how restic behaves when backing up HFS+, showing what it is able to handle and where it fails.

Similarly to dar, restoring to a linux disk will produce error messages when metadata can not be reproduced. Whether you will be able to manipulate or save those problematic files separately, I am not yet clear.

Here is a short description of its installation and use in MacOS, along with a scheduler.

  • 1
    What I'm saying (in other words, giving you feedback) is that your answer is confusing and it sounds like you yourself have questions about "the answer" itself. If you're not sure about something, that is valid (it may and probably will get down voted, but that's not my point), however asking the community to give input on your answer and continue the discussion isn't how this site works. Again, it's not a thread.
    – Allan
    Commented May 28, 2020 at 18:24
  • Ok, I think that's the best I can do. In the past I had some trouble helping a friend with his backups. Interoperating with anything other than Apple products, or extricating from a Mac to another system, can be quite hard.
    – Diagon
    Commented May 28, 2020 at 20:53
  • Wow, you put a lot of research into that, thanks a lot. As for resource forks: I don't think it's a big issue. They aren't used a lot anymore nowadays and you won't be able to use them (or the information they contain) with Linux applications anyway. The key issue is rather to have data in a format which Linux applications can work with (and that's something no backup/data migration strategy can solve).
    – nohillside
    Commented Jun 2, 2020 at 9:47
  • Don't resource forks and metadata mostly apply to executables (or at least Apple-specific data formats) that I would have little expectations to see working on Linux? The bulk of data, be it database backups, photos and multimedia, text files, email dumps should not have the issue you are describing. Same way no one cares about copying Windows *.exe to Linux/macos. As far as issues go, I would expect more actual problems with DRM/licensed files than what you describe. I had a temporarily dead MBP and carried on just fine using my files on Windows for a while.
    – JL Peyret
    Commented Jun 2, 2020 at 17:12
  • @nohillside - Well, I'm concerned with the question myself. I have a friend who uses mac's and I was having trouble helping him. Regarding your comment, if losing resource forks and other metadata doesn't concern you (Extended Attributes, bsd-flags, ACL's, etc.), then you can just use dar or restic. That'll save all your data, but when you restore you can tell dar to ignore the irrelevant metadata. For restic you will get errors. I'm looking into how that's handled (waiting on responses), but I think you can ignore them or tell it to ignore those fields.
    – Diagon
    Commented Jun 3, 2020 at 11:05

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