Can you help me out with Time Machine on M1?

[Wando64]

I have recently acquired an M1 Mini and proceeded to complete a TM backup on an external USB3 spinner.
When this disk is connected to the M1 everything works fine and TM completes its tasks as expected.

However, after doing the initial TM backup I have moved the TM disk to my other Intel Mini which I use as a server and for remote TM backups. (I have multiple TM disks attached to this Mac and they are all working fine from other remote Macs)
While I can see the disk correctly as a shared disk from the M1, Time Machine will not present it to me as a possible destination.

Another strange thing I have noticed is that all of the files on the disk are hidden. I find this odd as by other Monterey TM backup disks (I have multiple Macs) all show the Sparsebundle image as a visible file.

The Disk is formatted as APFS encrypted, as are all of my other Monterey TM disks.

- Why TM on the M1 does not offer me the drive as a possible destination?
- Why is the content of the drive organised differently as every other Monterey TM drive I have used so far? (is this an M1 thing?)
- Why all of the data is hidden?

Thanks for your help. At the moment I am stuck.

 

[bradbomb]

Question, for the other TM drives you setup, did you start them as a local Time Machine backup on their machine before moving them to the server or was the first backup done over the network? I know on my end with my M1 Macbook Air, I actually have three separate TMs. One is done over my network to a Raspberry Pi that is setup to be a sort of Time Capsule. I then have a 1 TB SSD and a 5 TB HDD that I use to TM the machine. The 1 TB SSD is solely for the Air, and the 5 TB HDD carries backups of my Air, my old 2014 MBP that isn't used anymore and my 2012 Mac Mini

 

[Wando64]

I just remembered that to use the disk as a shared TM destination I have to CTRL click on the sharing dialog and allow this through the Advanced Options.
I can now see the disk as a TM destination from the M1 but it will not allow me to use it due to lack of permissions.
The permissions settings are exactly the same as the other disks, as far as I can see.

I am starting to think that maybe it is not possible to start TM locally and then move it to a server.

I have added another Volume to the APFS container and started a new remote TM on that volume and everything works as expected.
I guess while it completes the first backup I will also, from time to time, do a locally attached one to the original local TM volume.
The first remote backup is going to take at leat a week.

 

[Mike Boreham]

I am starting to think that maybe it is not possible to start TM locally and then move it to a server.

As I understand it, a TM backup to a local drive writes directly to the drive, while a TM backup to a networked drive writes to a sparsebundle, and you cannot move a drive between network and local. I may be out of date on this as I have only done local TM backups for years.

 

[Wando64]

As I understand it, a TM backup to a local drive writes directly to the drive, while a TM backup to a networked drive writes to a sparsebundle, and you cannot move a drive between network and local. I may be out of date on this as I have only done local TM backups for years.

Yes, that’s exactly what I have observed. Previously I had always assumed they were doing the same thing (why shouldn’t they?)

Now I am thinking how this would impact recovery if I wanted to attach the disk (to speed it up in case of full recovery).
Would that even be possible?

 

[adrianlondon]

Yes, that’s exactly what I have observed. Previously I had always assumed they were doing the same thing (why shouldn’t they?)

Now I am thinking how this would impact recovery if I wanted to attach the disk (to speed it up in case of full recovery).
Would that even be possible?

The procedure to doing a "full recovery" has changed. I have an old laptop I play around with, and needed to do a full recovery of Monterey. It kept telling me my backup was corrupt. Useless message, as it turned out not to be true.

Now, you need to perform an internet recovery (or any other method to get the OS installed) then use Migration Assistant to read all the non-OS stuff from the backup. By that point, all your network will be running, so a NAS restore works fine.

Restore your Mac from a backup – Apple Support (UK)

Restore files from your backup.

support.apple.com

 

[bobcomer]

Yes, that’s exactly what I have observed. Previously I had always assumed they were doing the same thing (why shouldn’t they?)

A network backup is optimized for a network, a local disk backup is optimized for a local backup. They are not the same thing at all and have very different requirements. For a network backup you have to be worried about the connection itself, so it has to be restartable at the network packet level and most likely the bandwidth available is a lot less. A local backup doesn't have to worry about such things. I'd have been *extremely* surprised if you could move a local TM backup to be used as a network backup. TM machine backups aren't like file sharing...

 

[bradbomb]

I have another idea. Why don't you connect the two macs temporarily over thunderbolt creating a bridge network

Use IP over Thunderbolt to connect Mac computers

Connect two Mac computers together using Thunderbolt and set them up to communicate with each other using Internet Protocol (IP).

support.apple.com

Then connect to the drive as a shared drive and do the initial backup. You will now have the benefit of thunderbolt speeds for the initial backup and then afterwards, you can move the other mac back to its spot as a regular server.

 

[Wando64]

I'd have been *extremely* surprised if you could move a local TM backup to be used as a network backup.

I would have been extremely pleased, alas that's not the case.
The reason I tried is because... why not, but also I remember someone on this forum suggesting to someone else to do just that. Obviously without having tried it themselves first.

You will now have the benefit of thunderbolt speeds for the initial backup and then afterwards, you can move the other mac back to its spot as a regular server.

It turned out that it took just shy of 24 hours to finish the first 1.5TB backup. (it has literally just finished)
It wasn't too bad at all.
Your idea has potential but my Macs are in completely different parts of the house so for me it wouldn't have been practical at all.

 

[bobcomer]

The reason I tried is because... why not,

The very reason I do a lot of things with different computers.

And partially why I would have been surprised if it worked, TM is great for the base case, but try to get fancy, it's very frustrating to do! I know, because I tried too.

 

[bradbomb]

It definitely would be nice if it worked. I was reading some other convoluted ideas online, but it entailed sharing the drive as a shared folder on your own machine and then creating a way through terminal to connect to your own shared folder as a network drive to trick your computer that the local drive is a network drive so that the initial backup would be done in the required sparsebundle format.

I definitely like the network TM I have setup using the RPi as my main backup because it is automatic with no need to plug in drives. I keep those secondary backups done less regularly as I keep drives in a fire safe for dire emergencies and in those dire emergencies, I'm most likely not going to be worried about if my backup was the most up to date.