Time Machine backup fails in macOS 10.13.3 (High Sierra)

Also answering my own question: I solved my problem by:

1) Reboots (of my iMac and the Synology Server)

2) Disconnected the backup drive and reconnected it

3) Forced a manual backup

Time machine took quite some time and then performed the backup. Since then the automatic backup is functional again with no draw-backs since.

Hope, this helps.

Hi Pauline,

with disconnect I meant that in the Time Machine System Setup I chose "Select Volume", then clicked on my backup volume in the top and selected "do not use this volume" - it then still is in the list of available volumes. I do not use a detachable usb hard drive but i am backing up to a Synology server which can offer a suitable drive volume.

After that, I again chose my backup drive from the list and then pressed "backup now" to force the backup now - it took more time than usual, but it finished successfully and after that performed automatic backups as before.

Kind regards,

macofant59

To clarify: I was unable to unmount the drive because it was in use by the SMB daemon. I turned off sharing over SMB, and was able to unmount and run Disk First Aid to verify that the drive itself was okay.

As it turns out, I found some other threads where people were having similar issues backing up to networked Time Machine drives over SMB. Turning off SMB sharing and using AFP only seems to have fixed my issue.

Could SMB be the issue in 10.13.3?

Turning off the SMB sharing did the trick for me. Seems 10.13.3 doesn't like backing up over SMB.

Thanks very much for the hint. I tried terminal but got some permission related stop. before I went into details for it, I figured I would try the Disk Utility app. I use USB drive for backups. So I renamed, unmounted, and erased the drive. Please note that rename was just my choice to make naming easier. Anyway, after unmounting and erasing in Disk app, the backup is flying now. Showing 3 hours for 220GB full backup. I erased as I did not care about the past backups. I'm pretty sure that unmount then mount will do the job. Big thanks to OP. Cheers!

@Marco g: I didn't try to solve the problem by trying to fix the smb error. I switched in my Synology to afp protocol, see: https://www.synology.com/_images/tutorials/back_up_time_machine/mac_file_service .png

And this article but you have to choose for afp

DiskStation Manager - Knowledge Base | Synology Inc.

@iMac644 You should go into sudo mode on your terminal so:
sudo su

mount (and see which mount are there to your synology)

umount -f com.apple.TimeMachine.2018-02-13-103927@/dev/disk1s1

Last commando removes the mount where the last part for you specific is. The -f parameter does a force of the umount commando.

I'm using a disk connected to a Netgear router. Previously worked fine. Now Time Machine can't see the network volume. The previous method of getting the network share to appear when selecting a backup disk in the time machine control panel was to mount the volume using the location "smb://readyshare". That worked fine in the past but the volume won't show anymore in the control panel.

VERY frustrated with Apple.

Since 3rd of Feb '18 I am having the same problem. I am backing up on a mac backup bundle on a synology server which worked fince since years. Suddenly it reports the same error message as mentioned before "The network backup disk does not support the required capabilities" or, in German "Das Backup-Volume im Netzwerk unterstützt die notwendigen Funktionalitäten nicht." which appearently addresses the same error.

Any advice how to overcome the problem?

I forgot to mention the backup start and fail after few minutes.

the hard drive icon is on my desktop and tried these so far:

1. remove the back up in process

2. restarted my Mac

3. "Back up now" options under the time machine drop down ....many times :-(

No success so far

I'm having a problem with 10.13.3. It always BEGINS to backup, gets to 146.5 MG (of 3.65 GB to go)...then "Stopping," and poof! I can drag files onto the WD Passport Ultra, but hard to remember all the files I worked on that day.

My MacBook Pro is connected to LaCie 4 TB with a USB connection and cannot do a backup since I did my upgrade to 10.13.3

help, please!

Yes I do too

Hi, did you figure out how to grant the required capabilities? I was running into the same Problem:

Re: Time Machine/Server Question