Keep getting Time Machine backup failure

This has helped me in the past. Full reset of Time Machine

You're welcome, but Pondini deserves the credit. I'm just the messenger!

I have a few external drives daisy chained to each other. One of the drives is my Time Machine drive. If I'm not careful in the sequence in which I shut down any of the drives, it will result in my Time Machine giving me the same error message.

So if this is your case also, beware of that situation.

I was having the same problem on a 27" iMac Late 2013 running Mavericks 10.9.2. The Time Machine backup device is an external Toshiba 1TB USB drive.

The Full Reset steps above solved the problem.

Well, it solved the problem for a couple of weeks, but now it's failing again.

I'll do the full reset, and it works, but something appears to corrupt the Time Machine DB... not sure what. I raised a bug report with Apple.

I ordered a new Toshiba USB drive and installed it. Unfortunately, I am having the same problem.

The initial backup worked ok, and a few incremental backups worked fine. But then the backup failed, and kept failing.

I rebooted and the incremental worked ok. I assume it will fail again shortly.

It seems unlikely to be a drive/cable problem.

Here's the message in the console log just before the first failure:

com.apple.backupd[2336]: Error: (22) setxattr for key:com.apple.backupd.HostUUID path:/Volumes/Backup/Backups.backupdb/Alan’s iMac size:37

I don't find any other messages like this in the console log. (Note the possibly corrupted characters at the end of the message.)

I am wondering if there's some kind of intermittant hardware problem with my iMac. It doesn't seem that lots of people are having this exact problem.

I'm having that same exact problem on my MacBook Pro backing up to an external Toshiba USB attached drive too, whereas backing up to a FireWire attached Lacie drive on my MacMini doesn't experience the problem.

I've been using the USB drive for about a year without any problems so I don't know if it's about to fail, or there's a problem with 10.9.2.

After my incremental backups fail, I force eject the backup drive (a regular eject doesn't work) and wait for the light on the drive to go out. Then I disconnect and reconnect the drive.

Backups now work... for a while.

I'm wondering if OS X's state of the drive gets corrupted somehow... possibly if the drive sleeps when that isn't expected.

This is a new Toshiba 1TB Canvio drive, part number HDTC710XK3A1.

I may have solved this problem. I changed two settings in Energy Saver preferences:

Check Prevent computer from sleeping automatically when the display is off

Check Put hard disks to sleep when possible

I think it's the second one that made the difference. I haven't had an incremental backup failure in nearly a week.

From some other support posts, it seems to be a problem with iMac and external drive sleeping independently, and not handling the transitions properly. I couldn't find a way to tell the Toshiba drive not to sleep. Apparently telling OS X to put the hard disk to sleep forces it to explicitly manage the transition. So far, so good.

My OS X is 10.9.2, my iMac is 27" Late 2013 3.2 GHz Core i5, and the external drive is a USB connected Toshiba Canvio 1TB, part number HDTC710XK3A1.

Other manufacturers drives might work fine, depending on their sleep management.

Alan I'm definitely gong to give that a try. I did have the "put hard disks to sleep" checked already, but not the first one. I hope it makes a difference, because this is really a pain in the ***.

I've had this exact problem with my 2011 MBP and now my 2015 MBP using USB multiple external drives and different BlacX Duet. Just this week I started a new TM backup on a known good drive and within a day I get the same errors. I noticed that when I open the volume in finder the first thing it does is spin back up. It seems likely this power setting is the problem and I'm trying your suggestion.

TM simply does not work, has always been flaky, has corrupted files and continuously fails to back up. I have replaced drives, reset TM and tried every connection available (FW400 and 800, USB 2) all hooked directly into the iMac. Apple really needs to re-examine this. FW won't work at all. USB looks like it is working, but fails a couple days into a 3TB back up. I need to move on. Does anyone have a good third party solution? Thanks.