how to backup mac on external hard drive time machine

My M1 MBA has not managed successfully tp complete a TM backup in several weeks! One problem has been that the system seems no longer to be able to deal with a laptop going to sleep, which is a rather fundamental failing! However, since Catalina and Big Sur it has become a recurring nightmare, with backups taking hours, even days, and then anyway failing before completion. Over the past couple of years it has become horribly slow and unreliable when used over a network - and for anyone with a laptop that’s how one would want to use it! I’ve been backing up MacBooks to networked drives for years now - first using a Synology NAS, and then to external drives on a networked Mac Mini, and it used to be an easy, reliable, set-and-forget, option. Time Machine seems to be in need of some serious love and attention by Apple. Use Time Machine on your Mac with a Time Capsule and with USB and Thunderbolt disks.

I agree on the case-sensitive being a red flag, but Apple does say it’s OK: Apple Support Types of disks you can use with Time Machine on Mac If you mistakenly delete (or software corrupts) a file, sync will repeat that error everywhere, and there’s no (easy) way to recover a previously-synced version. Storing everything in the cloud is not a backup. I use Backblaze (and TimeMachine) for continuous and Carbon Copy Cloner for periodic backups. Continuous backup is much safer than periodic, but a periodic backup in addition to continuous is a good idea. If you’re not going to keep a TimeMachine drive connected continuously/frequently, I recommend looking at a different backup solution. I hope that means Time Machine has become more stable! I’ve experienced this twice, but it hasn’t happened to me in 4-5 years.

In that case, the only solution is to wipe out that backup and begin again. That said, I’ve also seen Time Machine get stuck on “preparing” because the backup became corrupted. (This is my experience only, and it hasn’t happened in years.) In the past, this seemed to be more likely to happen when the Time Machine disk was getting full. It’s not just copying files - there’s a lot more to it, and I’ve seen the “preparing” step take hours. Connecting just once a week may be part of the issue. Time Machine is designed to work with a drive that is connected continuously (or frequently, like daily).

How to backup mac on external hard drive time machine