Time Machine completed a verification of your backups on “Time Capsule”. To improve reliability, Time Machine must create a new backup for you.

Saw this posted in a forum, nt sure what it means but may have some bearing on our problems

Apple added support for SMB sharing to Time Machine in Sierra. The SMB developers are currently making the changes. One commenter mentioned that you could get better results when you are sharing an actual HFS+ file system instead of a sparse image.

This has been happening to me regularly now for a few months, hopefully it will get fixed. I am going to try to just manually back up my machine to see if that reduces the instances of corruption, because otherwise my backups normally only last a few days before becoming corrupt.

Two things to note:

1. This is not related to Time Capsule, I don't believe, since I am using a WD MyCloud NAS. This setup had been working good for me for about a year.

2. It is not completely consistent, because I back up two machines (an iMac and a Mac Mini) both with Sierra, but only my Mac Mini backup becomes corrupt. Odd.

Regardless, it is a major pain and definitely makes this setup almost worthless.

I had originally thought this might be due to inadvertently closing the lid on a MBP while a backup was in progress, but it just recently happened to an iMac (I backup both the iMac and a MBP to the Time Capsule, and within the last three weeks I've had to create brand new backups for both because of this bug.)

Note that DFA has always reported the TC's disk is clean.

This started happening to my time capsule on 2/13/2017. When it first happened I noticed the firmware was updated and so I thought it needed to run again because of that. However, today, 3/7/2017, it happened again. Now I need to run a full backup again which I plan to do tonight.

I have a 2TB time capsule and never dropped it and only moved once. I wish it would just work. I can't afford to simply replace it right now.

One option for everyone is to use Google Drive or similar system. I have most of my files backed up there by simply storing them in the Google Drive folder, and may move the others, save for bookmarks in Firefox.

mjlevo wrote:

i have a similar issue except i have one Mac that gets the error and the other backs up fine. both are running sierra -one is a 2009 iMac the other is a 2016 Macbook Pro. Macbook Pro backs up as it's supposed to, iMac keeps getting error.

My situation is nearly the same: an iMac and a MacBook Pro, both running Sierra. This stated need for full backup occurs frequently (every few days) on my iMac, but only now and then on the MacBook Pro. My iMac is going through one of its multi-hour repeat backups again as I write this.

Also, for the first time in over a year of use my current Time Capsule has developed a second backup file for my iMac. Now I have two, labeled: "iMac (2)" and the other "iMac (2) 1." After nine years of using various Time Capsules, I've never seen this. Until recently, this phenomenon didn't happen on any of my Time Capsules.

Any ideas for what's wrong with my system?

Any ideas for what's wrong with my system?

Sierra has more issues with backing up to a network drive.....like a Time Capsule.....than all previous operating systems combined.

My opinion.....Apple will never fix this.

If you are interested in having more reliable Time Machine backups, connect a USB drive directly to the Mac and back up that way.

Unfortunately we are also seeing reports of directly connected Time Machine drives with the same problem. Connecting directly is possibly more reliable, but it is not the solution.

I've been using Time Machine Scheduler (linked above). It overrides the hourly backup schedule. Reducing the frequency of backups seems to be helping.

BobTimmons wrote:

Any ideas for what's wrong with my system?

Sierra has more issues with backing up to a network drive.....like a Time Capsule.....than all previous operating systems combined.

My opinion.....Apple will never fix this.

If you are interested in having more reliable Time Machine backups, connect a USB drive directly to the Mac and back up that way.

I noted, above, that my iMac was doing another full backup, as I was typing my post. For some reason, the backup just stopped, and will need to be done again. This has also been happening at other times recently. Again, don't know why.

Agree Apple will probably never fix this, word has it they are about to go out of the wireless router business.

I do back up separately using Super Duper and a USB-connected hard drive. More and more I think that's probably enough, since so much of my stuff is now in iCloud as well.

I ran another full back up two days ago and it appears to be working okay so far, with backups every 1-2 hours depending on data since then. I have a direct connection - not WiFi so I can rule that out. Hopefully it stays. I will not be surprised to get the prompt again.

Unfortunately, that prompt will appear again....the only question is when, not if.

Not suggesting that you replace the Time Capsule....but would suggest that you can improve your chances of reliable backups if you also add a USB drive to the Mac and back up using Time Machine that way as well. You don't have to keep the USB drive connected at all times.....maybe backup once a day, or once a week, etc.

The issue is not the Time Capsule. The issue is much more likely to occur when backups go to a network drive.....like a Time Capsule or another network drive......not a "local" drive that is connected directly to a Mac.

Even though your Mac is connected using Ethernet to the Time Capsule, that does not change the fact that it is still backing up to a network drive......not a "local" drive.

In case you were not aware.....a network drive connects to a network router....and the Mac connects to the same network. A "local" drive....USB, FireWire, Thunderbolt, etc.....connects directly to a Mac, not to the network.

Time Machine backs up differently, and in a more complicated way to a network drive than it does to a local drive.

Unfortunately we are also seeing reports of directly connected Time Machine drives with the same problem

I'm sure they must exist......I've spent a hour plus trying to find them.....but cannot find any of these reports. Do you have a few links that you could provide for issues say.....in the last 90 days, or since Sierra was introduced?

You never have to look very far or long for issues with network drives.....we see posts about this multiple times each day.

Thanks, that's one. Keep those other links coming when you see them. I'm still searching as well.

My guess would be that 99%+ of the Time Machine corruption issues are being reported with network drives.

Stated another way, my advice to users is that their chances of keeping reliable backups improve dramatically with a "local" drive.

Apple Support at least admits the issue, but not in print. What they will not divulge is a plan to fix the issue.

I would be interested in what happens with Carbon Copy Cloner or one of the other well known third party backups to Time Capsule.

For what it's worth, I've been using Carbon Copy Cloner (CCC) for about 6 months to back up to a Time Capsule with a Mac running Sierra, and another Mac running El Capitan.

CCC suggested the option to create a sparsebundle file on the Time Capsule for each Mac to back up that way, and I accepted that option for both Macs.

So far, flawless results......no errors at all with backups.

For some odd reason, the slider bar on Time Machine Scheduler to set the interval is grayed out for me. I can set a limitation for time of day so basically I open the window for just a few hours at the end of the workday.

jimpal wrote:

. . . I noted, above, that my iMac was doing another full backup, as I was typing my post. For some reason, the backup just stopped, and will need to be done again. This has also been happening at other times recently. Again, don't know why.

Following this post yesterday (above), my iMac refused to back up at all. Backups could be manually started, but then they stopped after an hour or so. This after years of reliable Time Machine/Time Capsule (wifi connection) backups covering months of use, before Sierra. Clearly some corruption happened.

I fixed this new refusal to back up by going to Airport Utility and "Erase Disk." I erased the disk and I ran a new backup overnight. It worked as it should, and automatic Time Machine recovery is back to normal. The question is, of course, how long will it last until the subject note: ". . . . . To Improve Reliability, Time Machine must create a new backup for you" will appear again.