A couple of month old EX2 Ultra: Time Machine backups never worked properly. The initial backup was completed successfully. Backups worked okay for a couple of days, but then they stoped. Time Machine would start preparing a backup, but then stops with an error message 16 (the backup disk image could not be accessed).
After re-starting MyCloud or the router, backups resume for a day or two, but then the problem returns.
I’ve experienced the issue on macOS Big Sur and Monterey. On Big Sur the error message was different: the backup disk image is already in use, but the issue was exactly the same.
I did a quick search before posting, but I could not find a recent thread with the same issue. I’ll look again more carefully.
My Mac is on macOS 12.1, the NAS firmware version is 5.19.117.
The Time Machine backup share is given 100%.
I’m submitting a new incident report to WD support. Hopefully, they can figure something out. It’s not okay that a brand new product never works as advertised.
About giving 100% space to Time Machine, when configuring Time Machine using the dashboard interface, I set it to 100% for the share. Is this what you mean or there is something else?
Could be. Run a trial for a few days, when you are set to do several backups. Stay logged out, and when you log in to do something, log out again when’re you’re done.
Thanks. I think I have tried everything except for making sure to logout of web dashboard. I’ll try again the steps you suggest and make sure to log out every time.
I confirm that giving the share 100% works, but this option is pretty bad, long term. I have an 8TB drive, and using a 1TB limit was working great. Backups were limited to just about 12 months, so older ones were falling off. Now, the drive will just continue to fill with this backup.
Does WD acknowledge they are working to fix this with another update?
I’ve been able to narrow down the source of my issue.
It turns out there is an smb process (“smbd -D”) that continues to run on the NAS and use the sparsebundle even after Time Machine completes the backup (it’s shown as “R<” in top). When Time Machine 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, Time Machine backups resume for a few cycles, until it happens all over again.
Restarting the Mac does not help as the process runs on the NAS. But killing the process, restarting the NAS or the router, or even simply unplugging the NAS from the router for a few seconds terminates the process and allows backups to resume.
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.
Thanks. Yes, I’ve seen suggestions to add the TM volume in “/Volumes” to the Spotlight privacy list. Unfortunately, I’m afraid something has changed since then, and trying to add a TM volume now produces an error message:
<< “xxx” is a Time Machine backup folder. You cannot add it to the privacy list.>>
Also, I’m not so sure the problem is with Spotlight. I’m guessing that sometimes after a backup is done, its smb process continues to run on the NAS and use the sparsebundle, preventing the next backup session from accessing it.
over in the OTHER type of NAS they are having some timemachine problems as well.
one note said :
Notes:
If you want to encrypt your backups, use the encrypt backup option in Time Machine on your Mac instead of encrypting your shared folder.
We recommend you to set a quota to prevent Time Machine from occupying your entire storage space. The quota should be at least two to three times the size of your Mac’s drive, or two to three times the amount of data to be backed up.
Users can only set shared folder usage quotas on models that support Btrfs file system. If your NAS server only supports the ext4 file system, you can only set a usage quote for the entire volume.
For macOS Sierra (10.12) and later, Time Machine uses SMB as the default protocol. We recommend you to perform Time Machine backups via SMB.
I have one of their systems but not used that NAS for timemachine only the WD EX2 and PR4000 units. As TM has to be able to delete files if the storage is too full there may be sub-tasks running that do not finish before we do another backup ?
AND people using a laptop with sleep mode may have other backup problems.
( I do not have a laptop just lots of MAC minis and Windows machines.)
Same. I wrote to them that this is a bug and a workaround, not a solution, and they should push up the chain. The more people they hear from, the better. Best for you to write to support with a bug report.
I’m not encrypting the backup, and I’m not worried about TM backups taking over the entire storage on the NAS: I bought it just for TM backups.
From what I see by running ls -l /proc//fd/ | grep on the sparsebundle, smb processes that keep using it and preventing new backups from starting look exactly like smb processes running during active backups that go through properly. But I’m not an expert at all, so maybe they are some sub-tasks. In any case, it looks like SMB issues between the NAS and this specific MacBook Pro.
I’ve thought about disabling the Power Nap if the issues are related to sleep. Maybe I’ll disable sleep completely and let backups run for awhile to see if the issue occurs.
Thanks for the links. I’ll check them out, but I suspect the network is okay, as TM works fine on the other Mac.
Hi there! same less-than-100%-bug for me. I’m trying a new way: delete my backup, reset and set a brad new backup with an already set space of 120gb (not starting with 100% and then reduce). So far so good. It will take me another 2 hours to complete the first backup (85gb for my settings…I have a 120gb MacBook Pro 2018).
