Time Machine could not complete the backup.

I'm having the same issue. It's a brand-new 3 TB "Porsche" drive, sold right from Apple's own online store. It's partitioned so that some of the drive is formatted in Windows, for use with my Boot Camp partition (extra storage). But 2 TB of it are for the backup.

The problem goes away on its own after a day or so. Today after making lots of successful backups throughout the day, it re-appeared after I restarted into the Mac side, after having been in the Windows side. (But hadn't written to the drive at all while on the Windows side.) Anyone else who is having the issue using Boot Camp?

You don't specify exactly which message you're getting (there are several similar ones). See #C2 in Time Machine - Troubleshooting to get the details, and find a link to an explanation and possible fixes for the one you got.

The error message is that the disk is read-only. Your site suggests ejecting the disk, powering it off and disconnecting it, restarting your Mac, and trying again. But given that this is a recurring problem that "fixes itself on its own" and then recurrs sometime after that, I'm not inspired to fiddle with it to get it working only temporarily. Apple should fix this. Guess I need to file a bug report.

CSHSDude wrote:

The error message is that the disk is read-only. Your site suggests ejecting the disk, powering it off and disconnecting it, restarting your Mac, and trying again. But given that this is a recurring problem that "fixes itself on its own" and then recurrs sometime after that, I'm not inspired to fiddle with it to get it working only temporarily.

It also says, if that doesn't help, the backups may be corrupted. Try Repairing them per item #A5.

What Partition Map Scheme does the disk have? (Click the top line of the drive in Disk Utility's sidebar -- that will be shown at the lower right). It should be GUID, but APM will work. If it's MBR (Master Boot Record), a Windoze setup, that could be the problem.

If that doesn't help either, it's possible there's a problem with the disk, cable, or port. Try different cables and ports, and/or different combinations (a plug that works fine in one port may not make good contact in another).

It is GUID. I just reported the bug to Apple, so if it really bugs me, I'll try the steps on your site, otherwise I'll wait for them to fix it. The fact that it "fixes itself" in time leads me to believe it's not a corruption issue. Esp. since it's a brand new drive.

a few months back I went and had the harddrive replaced through the apple harddrive program, ever since I got my iMac back I have had nothing but problems. what they failed to tell me is why the also replaced the motherboard.

This is the 2nd time this has happened since January

Message was edited by: Oravec I'm using WD My Book Mirror Edition

Oravec wrote:

a few months back I went and had the harddrive replaced through the apple harddrive program, ever since I got my iMac back I have had nothing but problems. what they failed to tell me is why the also replaced the motherboard.

That's a pain, but has nothing to do with the "OSX can't repair the disk" message.

The directory is damaged beyond Disk Utility's ability to repair it -- the disk itself may be beginning to fail, but you don't know that yet. In theory, a heavy-duty 3rd-party Disk Repair app such as DiskWarrior might be able to fix it, but DW costs about $100 and may not be able to fix it anyway.

You need to reformat and erase the disk. See the blue box in #6 of Using Disk Utility. In step (b), take the time to do a one-pass zero-out. If that fails, the disk itself is failing. If not, it may be ok, but you should be suspicious of it.

It's always prudent to keep "secondary" backups, but especially so since your backup drive may not be reliable. See Time Machine - Frequently Asked Question #27 for some suggestions.

I am having a constant issue with Time Machine. I am running the latest version of Mountatin Lion on a 15" MacBook Pro, bought not even three months ago, 750G hard drive, 8G memory. I am attempting to back up to a BRAND NEW LaCie Starck 4T drive, partitioned using Disk Utility into 2T partitions. I have erased and reformatted the drive, unplugged and rebooted, deleted preference files, and done just about everything I've read about here. And still, I'm getting a failure to back up. I might as well just give up on Time Machine, what a **** up.

Are you getting the same message (the drive is read-only)? If so, there's likely a problem with the port, cable, or drive. Try different combinations of them. Also be sure it's formatted properly, per #C1 inTime Machine - Troubleshooting.

If it's a different message, see #C2 inTime Machine - Troubleshooting to get the details, and find a link to an explanation and possible fixes for the one you got.

I am also having this issue on a 10.6 server.

It is not a disk problem as we have now used two seperate drives.

While I haven't found a solution, I do have a workaround. I've created an Applescript which unmounts and then mounts the drive. I've then setup a reccuring schedule in iCal to run the Applescript once a day. This has worked now for a month.

Wilvo could you please provide a quick explanation of how you setup your script? I would like to do the same thing as the responses above all result in no long lasting fix which is starting to enrage me.

I too have tried different hard drives and get the same 'read only' message after 1-2 weeks of regular backups. This only started happening on OSX 10.8 for me, been using OSX with time machine ever since TM existed and have had spent $100's of dollars on replacement hard drives because I thought my other hard drives were faulty.

It looks like OSX is the problem to me and no one wants to admit it or get it fixed. Somewhat typical, Apple exceptionalism at its finest.

Unmount script

do shell script "diskutil unmount force /dev/DiskName"

Mount script

do shell script "diskutil mount /dev/DiskName"

Replace DiskName with your disks unique identifier, you can get this by going into Disk Utility, clicking on your drive and clicking info.

You then setup a recurring event in iCal and get it to call the scripts, first to unmount and then mount. I still get failures but i get at least 4 or 5 successful backups a day.

It is a very annoying problem.

Thanks Wilvo! I got the scripts working, but I had to change 'unmount' and 'mount' to 'unmountDisk' and 'mountDisk' respectively or it threw errors.

How did you get the calendar event to trigger an action/script? I can't work that one out.

Thanks

These are probably differences between 10.6 and 10.8. 10.8 iCal doesn't appear to have the run script option. You can save your AppleScript as an applcation and then use the open file option within iCal, try that.

Just in case anyone else is wondering, you open files with the "alert - open file" feature. I had no idea you could do that with iCal, which is now called 'Calendar' by the looks of it.

Thanks Wilvo, the umount/mount script is now working and my apparently read-only hard drive is working like a charm. Thanks to Apple for not solving the problem.