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

I had this problem before (12 months plus ago?) on a Macbook Pro connected to a Synology NAS over wireless. Backing up over a direct Ethernet connection seemed to make the problem go away. Then I went back to using wireless and it seemed fine. Suspected a new release of software on one of the devices fixed it

I've now got a MacbookAir (Yosemite) and its just thrown up the same problem. Did its first back-up to its own partition on the NAS and the following day has come up with the error message. Now in the tedious process of seeing whether a repeat of the backup will solve the problem.....

Pity that Apple does not seem to have a more helpful response to this problem that has been rumbling on for years. At least to give a better anaylsis of possible causes. The consequences of losing your back-ups are too serious to contemplate but Apple does not seem to be taking it seriously, judging by the lack of responses

I've been having the same problem for some time now. I've reached out to Apple, and yeah, it's a pity....they won't acknowledge there IS an issue. But quite clearly there is. It's getting frustrating when we pay SO much for Apple products, only to have less and less support! IF Apple is moderating, WHY won't someone hop on and say SOMETHING!

I haven't been able to back up my iMac in months because of this.

IF Apple is moderating, WHY won't someone hop on and say SOMETHING!

The Terms of Use Agreement that you "signed" make it clear that this is a user-to-user support from. Apple will not respond here.

As far as "moderating", the forum moderators try to keep things organized, but they are neither "technicians" nor "support" folks.

Please contact Apple Support directly if you have an issue.

http://www.apple.com/support/contact/

I just got this issue this morning when I woke up. Last night I updated to 10.10.2 on my MacbookAir 11" 1.3ghz i5 I purchased last May. It backed up at 10:56 p.m. last night to my 2TB TC that I purchased in 2010. I thought perhaps it could be the tc. However, my wife who has the same, identical macbook air purchased at the exact same time...I clicked "backup" 5 minutes ago, and it backed up with no problems. So, I don't think it's the TC. I live overseas, so calling support is less than easy. Any ideas as to what to do?

After having switched to a NAS solution over a wireless network I had the issue of the "...time machine must create a new backup...".

A tried a lot - here a special thanks to Pondini's webpage - and I think I can narrow it down to some workarounds:

In my opinion:

# it is not related to the hardware (NAS drive)

# it is not directly related to any software versions, but it appears that the time machine software is too slow in processing the backups when connected over a wireless connection. And this is the cause for the failures. The probability that the user interrupts the backup process (closing the laptop lid,...) is much higher as it lasts much longer and the backup is corrupted by the interruption.

# the solution would be to rework the time machine software (to do Apple) for a better handling of the backups.

# until then a potential workaround is to deselect the option "backup while on battery power" - then just opening the laptop, working a bit and closing it will not lead to a backup attempt - thus no corruption. And when you connect it to a power source and want to leave before the backup is finished, you should either interrupt the backup by clicking "stop backing up" on the menu or leave it running.

It is a bit a non-technical approach for a software problem, but so far it works and it is reproducible.

Regarding Apple User 0815, sadly I don't think this is it. I'm using a wired ethernet connection with my time capsule so it's not a wireless issue. I have a brand new iMac with a fresh install of Yosemite and time capsule that's less than 6 months old. With new hardware, I think we have to eliminate hardware as being the issue. Next try is to use a non-network attached solution such as a thunderbolt drive and see if that solves it.

I'm part of the bewildered chorus of people frustrated by this problem. I bought a WD MyCloud (a NAS) to allow multiple devices in the house to back up. The problem described here occurs on both devices from time to time. I dug out my old external HD and bought another for both of the machines. My MBP (which is running the current OS X) backs up alternately to all three machines. All the direct-connected machines work fine (and have for the 5–7 years I've been using TimeMachine with one). The MyCloud backup just corrupted on my today for the second or third time in the last month. It's maddening and, yes, destroys the whole point of having backups.

same problem to me.

MBP connected via wifi to WD MyCloud 2TB. every month that message about the verification backup problem.

My iMac connected via ethernet through Powerline to the NAS has no problem until today...

still waiting for a resolution...

Can't believe this problem has been going on so long. I had this problem when using a hard drive connected to my latest version Airport Extreme. Thought perhaps a NAS would be better, so am using a WD MyCloud 2TB for backup (as well as other features), but same message pops up roughly every other week...

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

So frustrating. Apple: why no solution?!

Spend the money and buy Carbon Copy Cloner.. particularly for Yosemite.. TM is just unreliable. Period!!

You will find a third party is reasonable price and works better.

...yes! Why no solution!?!?

One solution to this problem is to have Time Machine make a backup to two locations and when one of them gives this error you simply delete it and copy the other intact backup to that location.

This has been a long standing problem since Lion and is happening due to the way Time Machine is engineered. The only way to get this fixed is to voice it out really loud by filing a bug report (lots and lots of them duplicated by many users) to get Apple to re-engineer Time Machine.

You need to include diagnostics data with your report because that's the first thing that Apple support engineer will ask.

To collect diagnostics, go to Terminal and then run the following command:

sudo tmdiagnose

It will generate a report on the desktop. You'll need to attach this file on your bug report. It would be best if you run this command before you start a new Time Machine backup (e.g. while the "start new backup" prompt is still showing).

I got the same issue with latest OSX 10.11 on my QNAP nas, USB disk backup seems work fine.

add me to the list of people bitten by this. I have an iMac hardwired to the TM, and have had no problems till tonight. It is about 18 months old.

lots of people complaining about this online/here

does anyone have actual answers to:

a) can I feel safe these problem is not my iMac, or something on it (can I trust separate CloneCopy BUs I make of it ?)

b) seems many people continue to get these after the first one ? why is this ?

c) is it HW fault on the TM ?

d) is this any way to make this stop ?

e) was the problem caused during the last ** ? I guess I'm asking if the Verification is performed after each **, if not, when ?

f) is there a way to perform a manual Verification of the TM ** ? I can't find it, if there is.

thanks

why doesn't it just go back to the last valid **, wouldn't that be the point ?