[freetonik]

My partner’s iMac recently died (seemingly the Radeon graphics card had failed, which is not uncommon on 2017 model). It was frustrating to find out that Time Machine was not operational for 8 last months. It was always connected. There were zero indications of any issues. It just stopped backing up at some point. The disk had enough space.

In the past I had problems with network attached Time Machine destinations, but now I have zero trust even in the “native” USB-based method.

[hedgehog]

I don't know what's happened to Time Machine, with the capabilities available in APFS etc it should be much better if anything. But it's not. Thankfully the failure mode I've experienced didn't lead to data loss but I definitely don't trust it any more.

[freetonik]

Luckily I had Backblaze backup set up on our machines. In addition, this older iMac can still be booted up in Target disk mode, i.e. acting like an external drive. So I could salvage all data.

Another funny thing is that Mac’s built in diagnostic mode, after running for good 20 minutes, proclaimed there were no issues with the system. Even though it was clearly failing in the graphics department, even when booting into an installer usb drive (or even a Linux live mode).

[dgxyz]

It was always shit. I have seen horror stories going back since the day it came out.

Think my favourite was a conceptual flaw. The lightning strike. You need a completely offline backup or you don't have a backup.

Edit: using ChronoSync and two external (hard) disks, rotated once a month off site at the moment. That has a nice fat VERIFY button on it.

[NegativeLatency]

Did time machine start using the APFS features? I thought it was still doing HFS+ stuff?

[kjkjadksj]

It is astounding to me how unperformant time machine is. When I went from the 2012 mbp to the m3 pro there was zero difference in time machine peformance. Still taking half a day for a couple gb changes. Moving at orders of magnitude below disk read write. Wtf is even happening under the hood of the time machine service? Rclone would be like warpspeed in comparison.

[this-is-why]

This is what worries me. I’ve used Time Machine for almost 20 years and it has provided seamless transitions to new MacBooks. But how do I know if it is currently borked?

[MoonWalk]

I heard in the past that Time Machine backups would inevitably become corrupt because of a fundamental defect. Pretty vague, I realize, but I wouldn't have used it anyway; I rely on Carbon Copy Cloner to back up only what's important.

[kccqzy]

The problem was directory hard links. Fortunately that particular issue was resolved by replacing it with APFS snapshots. But the reputation damage is done; I don’t really trust Time Machine.

[wutwutwat]

test your backups. disaster recovery gamedays shouldn't be optional. you can spin up macos vms on your mac (or in qemu on linux if you want, or in docker, or rent a mac cloud vm) and test the backup restore.