I use a Synology NAS to backup my family's MacBooks. Two are still working fine, but one of them was unable to make a backup for about a week. Because the other two MacBooks are still fine I am pretty sure that the issue is not related to the recent MacOS update nor to the recent Synology firmware update.
The log file has repeating sections like the following:
2021-11-05 10:29:52: TMPowerState: 2
2021-11-05 10:30:22: TMPowerState: 2
2021-11-05 10:30:22: Not prioritizing backups with priority errors. lockState=0
2021-11-05 10:30:22: Starting automatic backup
2021-11-05 10:30:22: Attempting to mount 'smb://[USERNAME]@Synology._smb._tcp.local./time-machine'
2021-11-05 10:30:26: Mounted 'smb://[USERNAME]@Synology._smb._tcp.local./time-machine' at '/Volumes/.timemachine/Synology._smb._tcp.local./3C582361-50A6-47F2-947C-86A99A2B1A66/time-machine' (111,02 GB of 805,31 GB available)
2021-11-05 10:30:26: Initial network volume parameters for 'time-machine' {disablePrimaryReconnect: 0, disableSecondaryReconnect: 0, reconnectTimeOut: 60, QoS: 0x0, attributes: 0x1C}
2021-11-05 10:30:26: Configured network volume parameters for 'time-machine' {disablePrimaryReconnect: 0, disableSecondaryReconnect: 0, reconnectTimeOut: 30, QoS: 0x20, attributes: 0x1C}
2021-11-05 10:31:03: Failed to delete 'file:///Volumes/.timemachine/Synology._smb._tcp.local./3C582361-50A6-47F2-947C-86A99A2B1A66/time-machine/DCC98B45-7855-4FAA-B130-5FC56A017ED3.purgeable.sparsebundle/', error: Error Domain=NSCocoaErrorDomain Code=4 "“DCC98B45-7855-4FAA-B130-5FC56A017ED3.purgeable.sparsebundle” couldn’t be removed." UserInfo={NSUserStringVariant=(
Remove : Remove
), NSFilePa: "No such file or directory"}}
2021-11-05 10:31:03: Invalid mountpoint '/Volumes/.timemachine/Synology._smb._tcp.local./3C582361-50A6-47F2-947C-86A99A2B1A66/time-machine' - no volume mounted at this path
2021-11-05 10:31:03: Failed to unmount '/Volumes/.timemachine/Synology._smb._tcp.local./3C582361-50A6-47F2-947C-86A99A2B1A66/time-machine', Disk Management error: {
Action =: Action = Unmount;
Target =: Target = "file:///Volumes/.timemachine/Synology._smb._tcp.local./3C582361-50A6-47F2-947C-86A99A2B1A66/time-machine/";
} : }
2021-11-05 10:31:03: Failed to unmount '/Volumes/.timemachine/Synology._smb._tcp.local./3C582361-50A6-47F2-947C-86A99A2B1A66/time-machine', error: Error Domain=com.apple.diskmanagement Code=0 "No error" UserInfo={NSDebugDescription=No error, NSLocalizedDescription=Kein Fehler.}
2021-11-05 10:31:03: Waiting 60 seconds and trying again.
2021-11-05 10:31:03: Cancelling backup because volume '/Volumes/.timemachine/Synology._smb._tcp.local./3C582361-50A6-47F2-947C-86A99A2B1A66/time-machine' was unmounted.
2021-11-05 10:31:03: Requested backup cancellation or termination
2021-11-05 10:31:04: Backup cancelled (22: BACKUP_CANCELED)
2021-11-05 10:31:04: Failed to unmount '/Volumes/.timemachine/Synology._smb._tcp.local./3C582361-50A6-47F2-947C-86A99A2B1A66/time-machine', Disk Management error: {
Action =: Action = Unmount;
Target =: Target = "file:///Volumes/.timemachine/Synology._smb._tcp.local./3C582361-50A6-47F2-947C-86A99A2B1A66/time-machine/";
} : }
2021-11-05 10:31:04: Failed to unmount '/Volumes/.timemachine/Synology._smb._tcp.local./3C582361-50A6-47F2-947C-86A99A2B1A66/time-machine', error: Error Domain=com.apple.diskmanagement Code=0 "No error" UserInfo={NSDebugDescription=No error, NSLocalizedDescription=Kein Fehler.}
2021-11-05 10:31:04: Cleared pending cancellation request
Interesting detail: The folder that failed to unmount (/Volumes/.timemachine/Synology._smb._tcp.local./3C582361-50A6-47F2-947C-86A99A2B1A66/time-machine in this example) is always different on each try. And it is always created at the time the backup attempt started. And it always contains only one empty folder called time-machine:
drwxr-xr-x 3 root wheel 96B 5 Nov 10:30 3C582361-50A6-47F2-947C-86A99A2B1A66
What I tried so far:
- Run hard disk tests on the Synology NAS (all HDDs are fine)
- Disabled and enabled Time Machine
- Run Disk Utility – First Aid on all disks
- Manually deleted all existing folders in
/Volumes/.timemachine/Synology._smb._tcp.local./ - Told Time Machine to remove the existing backup and start from scratch
- Rebooted the Mac a couple of times
None of that made a difference. Any idea how to fix this issue?
