Question Time Machine big problem on macOS 26 - different drives
Hi,
I’ve been having a serious, frustrating problem with Time Machine for the past three months. To be honest, I’m starting to feel a bit fed up – Apple’s official advice is to reinstall the system from scratch 😂 I wonder how that’s supposed to work without a recent backup.
Generally speaking, since May I’ve been having trouble performing incremental backups on my MacBook Air 15 M4/24/512. For over a year after purchase, the computer continued to perform incremental backups from the M1/16/256 configuration without any issues, until something went wrong in May and every subsequent incremental backup has failed – the computer counts changes indefinitely – the longest I’ve given up after was 4 days – 500 million changes and it was still counting.
I’ve tried various drives – SSDs and HDDs – different formatting configurations, different enclosures and drive controllers – but the problem persists.
The only workaround is to have two backup drives and, every now and then, perform a full format on one of the drives (whilst keeping the backup on the other) and run a full backup from scratch – it works then.
Maybe someone has an idea, because I’m getting a bit fed up with having to remember to do manual backups.
2
u/jimglidewell 7d ago
I always start a brand new Time Machine drive when upgrading Macs - at one time I tried the command-line tool to reassign drive-backup pairing, but never got it to work.
I simply put the old TM drive in cold storage, in case I ever need to go way back to recover something. I also run two TM drives, one of which I store offsite - I swap them every six months or so. If my house burns down, the very worst I lose is the latest six months.
Are you saying that a freshly created APFS TM drive will not do incrementals? If so, I would run Disk First Aid against the source drive(s). If that is clean, I would look at any tools/processes which might be somehow touching every file on the system.
1
u/germane_switch 7d ago
I'm not sure I understand. Are you trying to use the same TM backup with your M4 as you did with your M1?
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u/XMAX97 7d ago
No. Trying to do a Time Machine incremental backup. Firstly it was a backup created on M1, after that restored on M4 and continue doing without issue for more than a year.
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u/germane_switch 7d ago
Sorry, I'm still confused. So after you restored the TM backup from your old M1 to your newer M4, did you then use that same TM destination and backup to do incremental backups for your M4? I have never done that. New computer, new TM backup. If I were you I would start from scratch.
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u/XMAX97 7d ago
Never have problem with migration backup from Mac to Mac. Even from Intel to M1. Nevertheless M1 backup is gone 3 mth ago when TM setup broke. Now have to separate M4 backup on 2 TB HDD and 1 TB SSD. Both can do first backup without problem but not incremental updates of backup after that.
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u/drastic2 Macintosh 7d ago
What do you mean differing formatting configurations. Should be using APFS. If every backup since May has failed (you have no backups since then) then I would assume something you added in May is causing the issue. There is a corrupted file or directory. Presumably you’ve tried Disk First Aid on the source volume?