Time Machine Problems

[uptownnyc]

I've been using my Synology NAS as the destination for my Time Machine backups for a few years. I have a wired iMac and a MacBook Pro that I use both wired and on wifi that have both backed up to that host. My iMac is still backing up without any problems, but my MacBook Pro hasn't been able to perform Time Machine backups for a few weeks now.

I'm able to "see" the backup disk from my MacBook Pro, and the Time Machine UI says:

"Looking for backup disk."
"Preparing backup."

But then I get a popup that says "Backup Disk Not Available - Try backing up again when "NAShostname" is available.

I've tried over Wifi and over a wired network connection. I've also tried choosing "Select Disk" and choosing the destination disk. I see both "NAShostname" and "NAShostname.local" listed in the available disks. Backup disks shows "TimeMachine on NAShostname" as what should be the active disk. My iMac shows "NAShostname.local" as the active backup disk.

Any ideas? Seems like since it's working fine from the iMac it should do-so from my MBP as-well, but I'm at a loss as to how to resolve this one.

 

[chown33]

What OS versions are on each Mac? Exactly which Mac models?

Try making a disk-image on the NAS, mount it, then see if you can set it as the TM backup disk.

I suggest "sparse bundle" as the image format.
The file-system should probably be APFS, if OS version is capable.

 

[uptownnyc]

The iMac is an ancient late 2012 running Catalina (10.15.7). The MacBook Pro is a late 2015 running Monterey (12.7.2).