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

Having same issue - getting the same message. I am concerned about performing backups regularly then having the backups erased by Time Machine and starting over. Defeats the purpose of regular incremental backups if I can't go back and retrieve a file from an earlier backup.

I am backing up iMac and multiple MBPs to a Synology NAS using Time Machine. I have been using this configuration for a couple years now. This message started occuring recently and has occured multiple times on one of the MBPs. But I have seen it on two of the machines. I am currently running 10.8.4 on all machines.

Reading through this thread, it appears that this issue occurs on WD, QNAP, Synology and even Apple TC. I don't see how this can be attributed to certain hardware being unsupported.

I am not comfortable running commands like fsck, hdiutil, tail, etc in a command line interface on my NAS. That is why I am using Time Machine in the first place?

Any recommendations on alternatives to Time Machine?

Although you are correct that Time Capsule is not immune.. the issue is wireless I think.. far less robust than using ethernet.. TC is still the best choice. if you use TM.

There are other backup software.. CCC is a good one.. and is not based on AFP file so has much less issues with network drives.

But I have only had this happen once in about 2years using a Zyxel NAS.. but always ethernet.

If you want Time Machine to really work well.. use ethernet.

The method of backup used by TM is so complex the fact that wireless error correction is just not up to the standard of ethernet and the amount of data going back and forth.. gives rise to issues.

steve.mccormick2 wrote:

. . .

Reading through this thread, it appears that this issue occurs on WD, QNAP, Synology and even Apple TC.

See #C13 in Time Machine - Troubleshooting for some things that can cause this. It seems to be much more common on NASs, likely because working with Time Machine isn't a main feature of most of them -- TM has some complex, unique requirements, and the makers may not get it entirely right, especially error detection and correction.

Any recommendations on alternatives to Time Machine?

CarbonCopyCloner and ChronoSync can work over a network.

I use CCC (great product, with great support), but not over a network, in addition to Time Machine to a Time Capsule and a USB drive connected to it, with no issues).

Thank you for the quick response from both Pondini and LaPastenague.

Being physically connected to perform a backup may work for a single machine. But we have 3 machines in different parts of our home. I have no desire to run ENET cabling throughout the house just so I can perform backups.

And dumping Synology for TC is not a good option either. TC is inferior in terms of application support, performance, RAID support, storage scalability, etc. Synology clearly states that they support Time Machine on their NAS Products: www.synology.com/us/solutions/backup/

I don't want to dump Synology just so I can use Time Machine.

iMac and MBP, Cisco router, and Synology NAS are high quality products. All running the latest software and standard networking protocols. They work great together except for this TM backup issue.

steve.mccormick2 wrote:

. . .

And dumping Synology for TC is not a good option either. TC is inferior in terms of application support, performance, RAID support, storage scalability, etc.

Correct. The TC was not designed for that. It was designed specifically as a backup destination for one or more Macs to back up to with Time Machine, automatically and with very few options or controls, so the novice user, who's probably never used any sort of backup app, can do it easily. You can do some other things with them, but it's usually not a good idea.

NASs, on the other hand, are good at the things they were designed for. Working well with Time Machine's very different requirements (AFP file sharing and special requirements for TM) may not be a high priority for them. Most users I've seen post about this combination say neither the NAS maker nor Apple provide much help.

Synology clearly states that they support Time Machine on their NAS Products:

That doesn't make it dependable. There are any number of posts in this and other threads where it doesn't work well. Some other NAS makers make the same claim, many of whom also seem to have trouble doing it properly.

Like it or not, the fact is, many folks find the combination unreliable, and have since Time Machine was first released, in October 2007. Seems unlikely that's going to change any time soon.

Take a look at CarbonCopyCloner and ChronoSync, and I'm sure there are others that will work over a network.

Pondini - Thanks I will definitely look at both solutions. Consistent, reliable backups are a high priority for me.

The earlier comments about WLAN error correction not up to the standards of ENET don't make sense to me. Error correction at the networking layer is proven technology. I understand that wired provides higher performance. But millions of people use home WLAN to download very large files (including OSX updates) and perform all types of transactions and file transfers that demand error free transmission.

Thanks for your comments

I have found that the error no longer occurs if you DO NOT use a network drive with Mountain Lion OS. If back up drive is directly connected the computer it seems to solve the problem.

I get this message also. I'm running a MacBook Pro, 13-inch, Early 2011, Processor 2.7 GHz Intel Core i7, running Mac OS X Lion 10.7.5. I use Time Capsule for my backup. Do you think getting a new Time Capsule will solve the problem? Maybe this new one: http://store.apple.com/us/product/ME177/airport-time-capsule-2tb

Hard to tell. In theory, they've improved the innards and/or firmware, but we don't know yet.

See #C13 in Time Machine - Troubleshooting for some possible causes.

Hey Guys!

I have a theory: NAS often have "included" anti-virus software running (takes ages to scan all there is, but who cares?). I saw, that a spam-mail attachement was moved from within the back-up to the vault. Maybe this is, what corrupts the back-ups. Any opinions?

nope

The fundamental difference in this case and the root cause of the problem seems to be the sparsebundle disk image created by Time Machine for backups to a network drive. These have a tendency to become corrupt, in particular when they grow large and complex. I have experienced similar problems when using rsync for transferring data to a sparsebundle on a network drive; eventually it becomes corrupt. The solution in that particular case was simple, since normal sparseimages does not seem to share the same deficiency. For Time Machine sparseimages are not an available option, however, but for local drives no sparsebundles are used – and thus the reliability of Time Machine increases.

Any chance of Apple improving the reliability of sparsebundles sometime soon?

Interesting analysis. It seems to make a lot of sense. One way to validate is to investigate whether ChronoSync, CCC and others use sparsebundle for NAS backup/sync. They don't seem to have the same issues that Time Machine has with NAS.

This seems to be the fix.

http://www.garth.org/archives/2011,08,27,169,fix-time-machine-sparsebundle-nas-b ased-backup-errors.html

Hardware: iMac Core i7, 2.8 GHz, running 10.7.5; 16 gig of ram, using TM to back up to Time Capsule (late 2009)

I too have this problem - it started about 3 months ago. About every 3 weeks, I would get that message. After reading this thread, I decided to try Apple support. After two months, being bumped to a higher level support, I was told to delete:

-Carbonite;

-Parallels; and

-dyndns (a static provider I need).

There was no guarantee that any of these were actually the problem, but I was told to start with this, and see what happened. I don't mind disabling Carbonite, but I can not delete Parallels because I need that to run my business. So, my case was closed.

What I am not clear on is whether a new TC might solve this issue? Support felt it was a software, not hardware problem. But their solution is not possible, so I am - maybe just wishful thinking - wondering whether anyone has had luck with a new TC?

Thanks.