Q: Sierra and Time Machine

Same TM Issue. So I switched backing from Time Capsule to another HD and it worked immediately.

Is this a TC issue?

My Time Machine was stuck too. Following advice on this forum I added my backup drive to the Spotlight exceptions. A few minutes after that action a pop up advised that I create a new back up file and Time Machine started its thing.

Thanks for suggestions.

In my case, I uninstalled the Sophos antivirus and it is backing up without any problem. It has already backed up 50gb in an hour.

I turned off Sophos on demand scanning, and my Timemachine backup is finally running, and backing up to my Time Capsule.  In trying to figure out how to solve this, I ran across a useful command which can be entered in Terminal and which allows you to monitor the progress of a Timemachine backup. 

log stream --style syslog --predicate 'senderImagePath contains[cd] "TimeMachine"' --info

OK...

I link your info  to the discussion I started...;

Re: How can I see Time Machine activity in Console with macOS Sierra.

Jur Kuipers, The Netherlands

Put in the Terminal Command log stream --style syslog --predicate 'senderImagePath contains[cd] "TimeMachine"' --info

TM is running, but... no Terminal TM-info here...

Sorry @chuckosmund ...

I was wrong...

Just got TM-info in Terminal... !!!

Thank you!

Jur Kuipers, The Netherlands

I have the same issue.

After upgrading to Sierra, I encountered to very slow backing up at the first time, but it was still working (generating a backup).

Eventually it started not working at "preparing...," though.

I initialized the backup HDD and tried baking up.

The initial back up was done very smoothly and some of the following differential backups too.

However It started failing again at a new differential back up.

I repeated such (initializing the HDD, baking up from a scratch, making hourly differential backups, etc.) several times.

Eventually the process fails.

This morning I found a file named 2016-09-25-001350.inProgress in the backup HDD and I moved it to Trash (the file cannot be erased, though).

Since then the differential backup has been working several times.

I have to see if this has fixed the problem or not for some more time.

I feel that the above backup failure at a new differential backup started once the "initial encryption" was completed.

After the initial backup, the encryption started and went well. New differential backups were made smoothly during that encrypting. However suddenly after the (deemed) completion of encryption it appears to fail a new backing up.

I am not sure if the encryption is a cause of this trouble and if the encryption was truly completed.

I can look into and manipulate all of the folders/files in the backup HDD by Finder. Is this normal?

Setting "On-access scanning" to disabled in Sophos Anti-Virus resolved the always "Preparing Backup..." and the "AFP_VFS afpfs_vnop_ioctl:  afpfs_FindForkRef failed -1" being logged continuously issues for me. 

Disabling Sophos AV was the only change that I made.

Now, who's issue is it, Sophos or Apple.

My story on a Mac mini (Late 2014, 2.6Ghz Intel, 8GB RAM): after upgrading to Sierra, Preparing for Backup lasted almost half an hour and concluded to a backup size of ~25GB but it was taking hours to complete on both my Time Machines (>8hrs to reach 109MB).

Mac, SMC and PRAM resets did nothing.

What worked: stop indexing my Time Machines for Spotlight and disabling Sophos.

Now everything's back to normal

Hope this helps

Wow man, you nailed it!!

I had the same problem, time capsule backup not working so I had attached an external usb drive. Again backup was very slow but when I switched off Sophos it's backing up very fast!!

Thanks!

Ron

Thank You, This corrected my backup problem. I turned off all protection and the backup started. I am now trying to see what part of Sophos is causing the problem.

My problem is still on going.  Preparing back takes forever.  Then it starts backing up, but at this rate it will take about 60 days to complete.  I don't have sophos.  This is very disappointing from Apple. 

Try the spotlight exception. I don't have Sophos either but excluding the backup drive from spotlight immediately solved the issue for me.

Disabling Sophos fixed it in my case.  Also, I tried access some old files in time machine from a backup a few months ago, and all I got was "waiting..." on the date I picked.  Disabled Sophos and that also fixed that problem.