Time Machine error: The backup disk image xxx.sparsebundle could not be accessed (error 16)

[msvadi]

I'm having issues with Time Machine Backups to a NAS (WD MyCloud EX2 Ultra). The Mac runs macOS 12.2, but I had similar problems with Big Sur.

The initial backup was completed successfully, and TM worked fine for a couple of cycles until it started returning an error:



Restarting the Mac does not solve the problem, but restarting the NAS, the router, or even simply disconnecting the NAS from the router for a few seconds and connecting back allows TM backups to resume.

I believe I’ve been able to narrow down the source of the issue. It turns out there is an smb process (“smbd -D”) that continues to run on the NAS and use the sparsebundle even after TM completes the backup (it’s shown as “R<” in "top"). When TM tries to start the next backup session, it finds that the sparsebundle cannot be accessed, because the smb process from the previous backup session is still accessing it.

After killing the process, TM backups resume for a few cycles, until it happens all over again.

I believe that the issue is somehow unique to that specific Mac (a MacBook Pro). I configured another Mac (a MacBook Air) to back up to the same NAS, the same share, and it works with no issues. The most obvious difference between the two Macs is that the sparsebundle for the Pro is very large (around 2TB; there are 1.5TB of data on the computer). The Air has only about 300GB of data on the disk, and its sparsebundle is much much smaller.

I would appreciate any suggestions on how to resolve this issue.

 

[Xerxes004]

I'm having this EXACT same issue. I restarted my NAS to see if it would work and the backup seemed to start, then stop after a few minutes with error 16 again.

 

[msvadi]

I'm having this EXACT same issue. I restarted my NAS to see if it would work and the backup seemed to start, then stop after a few minutes with error 16 again.

No solution unfortunately yet. I've been in touch with WD technical support, and there are not particularly useful so far: They guided me through a list of standard troubleshooting steps and resets that I have already performed numerous times.

I'm now doing a full erase and reset on the NAS, and will start from scratch and a new backup.

If you are also using WD MyCloud EX2 Ultra, some people in similar situations found that removing the limit from the backup share on the NAS (i.e. giving it 100%) solves the problem https://community.wd.com/t/timemachinebackup-works-intermittently/258142/33 . Unfortunately, that did not help me.

 

[Xerxes004]

No solution unfortunately yet. I've been in touch with WD technical support, and there are not particularly useful so far: They guided me through a list of standard troubleshooting steps and resets that I have already performed numerous times.

I'm now doing a full erase and reset on the NAS, and will start from scratch and a new backup.

If you are also using WD MyCloud EX2 Ultra, some people in similar situations found that removing the limit from the backup share on the NAS (i.e. giving it 100%) solves the problem https://community.wd.com/t/timemachinebackup-works-intermittently/258142/33 . Unfortunately, that did not help me.

No solution here, either, but I figured I'd post my specs fwiw.

Macbook Pro (16-inch, 2021) 64GB memory, 1TB drive.

NAS is a home-built FreeNAS with 1TB+ of free storage. I have a Time Machine SMB share on there with my old 650GB+ Time Machine sparsebundle. My old quota was 750GB since I only use about 300GB of storage on my Macbook. I increased the quota to 1TB, but that didn't fix my backups.

It backed up fine for 2 years, zero problems. Suddenly, my wife's Macbook and mine both stop backing up on December 22 with no failure messages or anything.

I will probably resort to just blowing away that Time Machine and starting over.

A couple things I'm going to try:

1. Copying my time machine to an external drive and plugging that straight into my computer
2. Scouring the internet for solutions (again)
3. Changing the SMB share to an AFP share, although I think Apple recommends SMB now (reddit thread)
4. Starting over with Time Machine. This worked for my wife's machine.

 

[Spicy Pepper]

I am also having this precise issue and weirdly it also started on December 22. Does anyone think that could have something to do with an update? (I'm not a tech person. I just desperately want my WD NAS to work.) I'm also working with at MacBook Pro, 16 inch 1 TB but I have 16 GB memory. Happy to contribute more information if it's helpful.

Pepper

 

[Xerxes004]

I tried to copy my .sparsebundle to a new drive and got a permission error. Maybe this has something to do with it? I will try a workaround and see what happens.

 

[johanPO]

Same issue here on both a MacBook and a Mac mini. I suspect it is something with the WD Firmware. It seems to have stopped after the latest update.
I did a reboot of the NAS and now it seems to be working on both

 

[Xerxes004]

Same issue here on both a MacBook and a Mac mini. I suspect it is something with the WD Firmware. It seems to have stopped after the latest update.
I did a reboot of the NAS and now it seems to be working on both

It's possible you're correct, but I am not using WD hardware. Everything seems to point to this being an SMB-related issue, probably on the MacOS side since that's the only constant here.

 

[Xerxes004]

I tried to copy my .sparsebundle to a new drive and got a permission error. Maybe this has something to do with it? I will try a workaround and see what happens.

Follow up: I've been completely unsuccessful in trying to copy out the sparsebundle, which is probably part of the issue. I'm still trying to find the magical permission set which allows me to access the data.

 

[Xerxes004]

I found this thread after searching google:

SMB broken with Monterey

I have a public Azure Files Share. After upgrading to Monterey I can no longer access the share. I have tried with another laptop on my network running Big Sur and it works fine, so I know it is not my network or firewall. The error I get just says it can’t find the IP or the server is down. I...

forums.macrumors.com

I'm going to try some suggestions in here and see what happens.

 

[Xerxes004]

Nothing I tried anywhere seemed to work at all. I just gave up and created a new data pool and SMB share. Initial backup is happening now. Luckily I only have like 400GB of stuff.

 

[David Eagle]

I had this error, whereby Time Machine completes an initial back and then gets stuck 'Waiting for Initial back up to complete' and then failing with Error 16. Following advice on another post, disabled SMB1 on my NAS, rebooted the NAS, rebooted my M1 MacBook Pro and kicked off Time Machine again. TM has picked up the existing spars bundle and has carried on running incremental backups, fingers crossed....

 

[Spicy Pepper]

That sounds fantastic. How do you disable SMB1 on your NAS? I'm sorry; I'm not very technical. My brother helped me to set up my system to begin with.

I've also rebooted and, separately, wiped my NAS. It temporarily fixed the issue but then I would get the "error 16" problem about 10 days after rebooting/wiping.

 

[David Eagle]

That sounds fantastic. How do you disable SMB1 on your NAS? I'm sorry; I'm not very technical. My brother helped me to set up my system to begin with.

I've also rebooted and, separately, wiped my NAS. It temporarily fixed the issue but then I would get the "error 16" problem about 10 days after rebooting/wiping.

I have a WD EX2 Ultra NAS, and its a configuration setting:- Settings>Network tab>Windows Services section, SMB Protocol parameter. Its now set to SMB 2, SMB3. Then I rebooted the NAS and rebooted my Mac book.
Hope this helps.

 

[bryanbrews]

This solution worked for me! My NAS backs up again via Time Machine.
From this site:

Fixing „Time Machine couldn‘t complete the backup to…“

Time Machine couldn’t complete the backup to “XYZ.local”. The backup disk image “XYZ.sparsebundle” is already in use. If the Time Machine backup fails, resolve it by adding full disk access for Time Machine in privacy.

miapple.me

How to fix „Time Machine backup disk image “XYZ.sparsebundle” is already in use.“​

If you are unable to backup because of the message “The backup disk image .. already in use”, follow this instruction:

1. Open „System Preferences“ on your Mac or MacBook.
2. Click on „Security & Privacy“.
3. Select “Privacy”.
4. Click the lock to make changes and fill in your Mac’s password.
5. Select „Full disk access“.
6. Look for “Time Machine” and activate the check mark.
7. Close “System Preferences”. Done!

macOS 11 Big Sur removed the full disk access selection for Time Machine Backup. As a result, Time Machine is unable to complete the backup. Fix it by giving again Time Machine full disk access in the privacy section in “System Preferences.

 

[Spicy Pepper]

I have a WD EX2 Ultra NAS, and its a configuration setting:- Settings>Network tab>Windows Services section, SMB Protocol parameter. Its now set to SMB 2, SMB3. Then I rebooted the NAS and rebooted my Mac book.
Hope this helps.

Thank you so much for the information. I followed your advice only to find that I'm already on the SMB2, SMB3 setting! So I guess that's not a fix for me since I've been on it and I'm still having the problem.

This solution worked for me! My NAS backs up again via Time Machine.
From this site:

Fixing „Time Machine couldn‘t complete the backup to…“

Time Machine couldn’t complete the backup to “XYZ.local”. The backup disk image “XYZ.sparsebundle” is already in use. If the Time Machine backup fails, resolve it by adding full disk access for Time Machine in privacy.

miapple.me

How to fix „Time Machine backup disk image “XYZ.sparsebundle” is already in use.“​

If you are unable to backup because of the message “The backup disk image .. already in use”, follow this instruction:

1. Open „System Preferences“ on your Mac or MacBook.
2. Click on „Security & Privacy“.
3. Select “Privacy”.
4. Click the lock to make changes and fill in your Mac’s password.
5. Select „Full disk access“.
6. Look for “Time Machine” and activate the check mark.
7. Close “System Preferences”. Done!

macOS 11 Big Sur removed the full disk access selection for Time Machine Backup. As a result, Time Machine is unable to complete the backup. Fix it by giving again Time Machine full disk access in the privacy section in “System Preferences.

Thanks for the information and the idea. I followed the steps and didn't find "Time Machine" in the list, so I added it and checkmarked it. I then attempted to backup: it didn't backup.

I hate to say it, but neither of these ideas worked for me. But I thank you both so much for posting ideas and possibilities!

 

[akrumm]

I am having the same issues as well. I'm getting an error code 19. My SMB settings were already to SMB 2, 3 and Time Machine already had full disk access. I'm running an M1 Macbook Pro into a WD EX2 Ultra. If I reboot the WD from its dashboard, it doesn't help. However, if I hard reset (unplug, plug in) I can get it to work for a few times. This issue has been going on since at least early Febraury.

 

[mikes18]

To fix the Time Machine Error Code, you need to delete the .sparsebundle file. Then create it once again in your local disk but not the Time Machine disk using the following terminal command:

sudo hdiutil create -size 50g -type SPARSEBUNDLE -nospotlight -volname "Time Machine Backup" -fs "Case-sensitive Journaled HFS+" -verbose ./Computername_MACaddress

Here, replace the size as per your choice, keep your own volume name, and replace it with your computer name and MAC address.

Now, log in to your NAS. Next, create a user account and create a shared folder. In Finder, navigate to Go > Connect to Server.
Type smb://TimeMachine@ip-address-of-nas/shared-folder-name for server address.

Click Connect. When requested, enter the password and save it in your keychain.

Now, copy the created sparsebundle file into the Time Machine share folder. The sparsebundle file is in your Home folder /Users/your-user-name.
On NAS, check the file is copied under your correct user account.
Finally, open Time Machine, select the Time Machine folder as the desired destination.

The backup will now start without any error.

 

[dariodic]

To fix the Time Machine Error Code, you need to delete the .sparsebundle file. Then create it once again in your local disk but not the Time Machine disk using the following terminal command:

sudo hdiutil create -size 50g -type SPARSEBUNDLE -nospotlight -volname "Time Machine Backup" -fs "Case-sensitive Journaled HFS+" -verbose ./Computername_MACaddress

Here, replace the size as per your choice, keep your own volume name, and replace it with your computer name and MAC address.

Now, log in to your NAS. Next, create a user account and create a shared folder. In Finder, navigate to Go > Connect to Server.
Type smb://TimeMachine@ip-address-of-nas/shared-folder-name for server address.

Click Connect. When requested, enter the password and save it in your keychain.

Now, copy the created sparsebundle file into the Time Machine share folder. The sparsebundle file is in your Home folder /Users/your-user-name.
On NAS, check the file is copied under your correct user account.
Finally, open Time Machine, select the Time Machine folder as the desired destination.

The backup will now start without any error.

Hello! I have the same issue and I wanted to try your solution. I've modified the whole command:

sudo hdiutil create -size 50g -type SPARSEBUNDLE -nospotlight -volname "Time Machine Backup" -fs "Case-sensitive Journaled HFS+" -verbose ./Computername_MACaddress

replacing the my computer name which is "Macbook Pro di Dario" so I replaced it like this Mac_Book_Pro_di_Dario

and inserted my WIFI mac address of the MacBook. Is this the Mac Address I have to write?

So in the end my command is:

sudo hdiutil create -size 50g -type SPARSEBUNDLE -nospotlight -volname "TimeMachineBackup" -fs "Case-sensitive Journaled HFS+" -verbose ./ MacBook_Pro_di_Dario_ 8c:85:90:7d:db:db

But it doesn't work and I get this message on Terminal:


dariodeagostini@192 ~ % sudo hdiutil create -size 50g -type SPARSEBUNDLE -nospotlight -volname "TimeMachineBackup" -fs "Case-sensitive Journaled HFS+" -verbose ./ MacBook_Pro_di_Dario_ 8c:85:90:7d:db:db
hdiutil: create: Only one image can be created at a time.
hdiutil: create: returning 0
Usage: hdiutil create <sizespec> [options] <imagepath>
hdiutil create -help
dariodeagostini@192 ~ %

What is wrong? THANK YOU!

 

[haudiyall]

Hi Everyone,

I noticed my TimeMachine backup had stopped working as of 2 weeks ago with error 16 (WD EX2 Ultra). I followed the advice in this thread and it seems to be working now. Here is what I did just in case someone else finds this thread:

Check connectivity on NAS
Verify SMB2,3 is selected in settings
Reboot NAS
On Mac - add in TimeMachine under Full Disk Access (wasn't in the list), check the box
Click Back up now in Time Machine

Fingers crossed but this seems to have fixed my issue at least for right now, will update this thread if it breaks again. Thanks to all those who provided helpful suggestions!

 

[Thirio2]

I had the same issue with my 2015 MBP, but my wife’s 2018 does not appear to have thi issue. That being said, I checked my backup file and it was current. Don’t know if this is a real issue or not.

 

[riskycodes]

Hi Everyone,

I noticed my TimeMachine backup had stopped working as of 2 weeks ago with error 16 (WD EX2 Ultra). I followed the advice in this thread and it seems to be working now. Here is what I did just in case someone else finds this thread:

Check connectivity on NAS
Verify SMB2,3 is selected in settings
Reboot NAS
On Mac - add in TimeMachine under Full Disk Access (wasn't in the list), check the box
Click Back up now in Time Machine

Fingers crossed but this seems to have fixed my issue at least for right now, will update this thread if it breaks again. Thanks to all those who provided helpful suggestions!

Thanks so much, I followed these steps, and it worked for me. Not sure which one was the key, but very happy to be backing up again!