I have my Unraid server and two Macs on a network. I've set up two separate shares for the Macs to use for Time Machine following Spaceinvader One's latest tutorial.

 

Time Machine on the older Mac (10.13 El Capitan) has worked flawlessly for months. This Mac is always connected to the network.

 

I'm having trouble with my new Mac (M1 Mac mini, 14.0 Sonoma) which is not always connected to the network. (It goes with me to the office at work and does a second TM backup on an external drive there.) It seems that Time Machine will only work for about a week or so with the Unraid share and then it will start having problems connecting. The only way to get it working again has been to remove and delete the TM backup entirely and reconfigure it.

fatfarmhqserver-diagnostics-20231023-1515.zip

On the shares tab can you hit Calculate next to your time machine share.  That share is currently sitting on the cache drive and disk 1 (probably due to an initial misconfiguration).

 

I think that the TM sparse file is actually on the cache drive which has currently 541G free space on it but your volume size limit for TM is set to 1TB, which means that this is going to fail.  (It takes a bit for TM to figure that one out)

 

TM shares ultimately are only a single file (a .dmg) so it has to be placed on a single drive and the volume size limit also has to be set accordingly so that there is always that space available on the particular drive.

 

TM setup issues have become somewhat of a mission for me as of late as there is very little information available online about NAS settings for this (it is technically an unsupported configuration from Apple), and this is where I am right now.

 

Also, in my experience, ANY TM backup that gets interrupted for any reason what-so-ever will never be able to continue backing up.  Interruptions could be restarting the server, making changes to share settings etc.

 

Thank you for your thoughts. The TM has been working well for a while now. I'll just have to wait and see what happens.

Sorry to resurrect an old thread, but I'm having TM issues after a flash drive failure. I'm all back up and running, but my TM just gets stuck on "Preparing to back up..." and the bar goes back and forth forever. If I run lsof I can see files in the sparse bundle open, so it's connecting, but it doesn't ever appear to do anything.

On 10/23/2023 at 9:43 PM, Squid said:

 

Also, in my experience, ANY TM backup that gets interrupted for any reason what-so-ever will never be able to continue backing up.  Interruptions could be restarting the server, making changes to share settings etc.

 

It's possible a TM backup was running when my flash drive failure took my machine down (it locked up after probably 2 days with a failed flash drive). When you said "never be able to continue backing up", do you mean that daily back up will never happen, or is the sparse bundle locked up and will never work again? Do I need to delete my existing sparse bundle and let TM start from scratch?

Thanks

whiteatom

EDIT: Well, it seems I solved my own problem. Removed the TM disk from MacOS settings and re-added it and it's backing up now! All good.

Edited August 7, 2025Aug 7 by whiteatom
Update.