Hi all, In the past, I've used partitions on a single big drive [1] to allow backing up multiple computers using Time Machine. So... imagine using a 3TB drive to back up three different computers. The great Pondini time machine pages [2] state that it is best to partition a drive when using it for multiple time machines.
Enter APFS, with its concept of containers and volumes which can share space. This seems to imply I could reformat my 3TB disk as a big APFS container with 3 volumes (instead of partitions). The volumes would look like separate drives (similar to partitions). So: would it be smart for me to reformat my 3TB drive as an APFS container and then use APFS volumes instead? It would get away from the fixed reserved spaces of partitions. It (perhaps) would make Time Machine happy about backing up to a networked drive [3]. To make this even more confusing, Apple has two High Sierra support pages which seem contradictory. One page says that you can share folders as a destination for Time Machine backups, but only if the folders are on an APFS volume [4]. Another page says that Time machine CANNOT back up to an APFS-formatted disk [5]. Of course a folder is not the same as a disk, but a volume _looks_ like a disk, so I'm guessing that I couldn't/shouldn't use volumes within a single APFS container for backups. (Or, does creating a single folder sitting inside each volume suddenly make APFS OK? [6]) Pondini did not live to witness APFS, so his otherwise fine advice is silent on this topic. I have not experimented with this yet, because it would involve wiping out the Time Machine backups which are up-to-date for one computer. Any help unraveling this would be appreciated. Bill [1] A relative term, so what I think is big now will be puny in the future (or even now). [2] https://urldefense.proofpoint.com/v2/url?u=http-3A__www.baligu.com_pondini_TM_4.html&d=DwIFAg&c=OAG1LQNACBDguGvBeNj18Swhr9TMTjS-x4O_KuapPgY&r=F2GFXrjLFqVo3VwvIlo_XYeEiRRjHv15rxcenz7A21woG2aFGcrzndoSsskxfmOs&m=GJtTCYwL3sogEOkyMO7tZmB9HngyxdLasmptufZVZZ4&s=3T94EwzDE94TaXnoxYZor5s0EGi2W4cuweEB4wZNPD4&e= (not at pondini.org anymore because Pondini himself passed away). [3] As soon as I upgraded to High Sierra, my current setup of using Time Machine up over wifi to a drive shared from my mac mini failed. This is the reason for revisiting this topic again. New Apple slogan: "It just works. Some limitations may apply." [4] https://urldefense.proofpoint.com/v2/url?u=https-3A__support.apple.com_guide_mac-2Dhelp_use-2Da-2Dshared-2Dfolder-2Dwith-2Dtime-2Dmachine-2Dmchl31533145_mac&d=DwIFAg&c=OAG1LQNACBDguGvBeNj18Swhr9TMTjS-x4O_KuapPgY&r=F2GFXrjLFqVo3VwvIlo_XYeEiRRjHv15rxcenz7A21woG2aFGcrzndoSsskxfmOs&m=GJtTCYwL3sogEOkyMO7tZmB9HngyxdLasmptufZVZZ4&s=XCLtjMPazQBfeCotsH1Dv5y3gRjPDCoDeRtlfzAAywg&e= [5] https://urldefense.proofpoint.com/v2/url?u=https-3A__support.apple.com_guide_mac-2Dhelp_disks-2Dyou-2Dcan-2Duse-2Dwith-2Dtime-2Dmachine-2Dmh15139_mac&d=DwIFAg&c=OAG1LQNACBDguGvBeNj18Swhr9TMTjS-x4O_KuapPgY&r=F2GFXrjLFqVo3VwvIlo_XYeEiRRjHv15rxcenz7A21woG2aFGcrzndoSsskxfmOs&m=GJtTCYwL3sogEOkyMO7tZmB9HngyxdLasmptufZVZZ4&s=mLj-md6gFaAl07eBlxnOFijPpy0mX-UaOVDH4q7xB5Y&e= [6] The crux of the problem is that Time Machine uses hard links to do its magic. APFS, however, does not support hard links for folders---search for 'hard link' here: https://urldefense.proofpoint.com/v2/url?u=https-3A__developer.apple.com_library_content_documentation_FileManagement_Conceptual_APFS-5FGuide_FAQ_FAQ.html-23__apple-5Fref_doc_uid_TP40016999-2DCH6-2DDontLinkElementID-5F17&d=DwIFAg&c=OAG1LQNACBDguGvBeNj18Swhr9TMTjS-x4O_KuapPgY&r=F2GFXrjLFqVo3VwvIlo_XYeEiRRjHv15rxcenz7A21woG2aFGcrzndoSsskxfmOs&m=GJtTCYwL3sogEOkyMO7tZmB9HngyxdLasmptufZVZZ4&s=EoqUwXDUP0Cvo4eiqYeaCfOKLJNC54bhxF-st11BsUA&e= _______________________________________________ MacGroup mailing list Posting address: MacGroup@erdos.math.louisville.edu Archive: <http://www.mail-archive.com/macgroup@erdos.math.louisville.edu/> Answers to questions: <http://erdos.math.louisville.edu/macgroup/>
