03-17-2011, 10:03 AM

It's an odd one.

Having replaced my ageing laptop with a nice new MacBook Pro a couple of months ago it was love at first sight and I decided to replace my Widows 7 desktop with a shiny new 27" core i5 iMac.

I back up the MackBook to a USB Iomega eGo using Time Machine.

While I mess about trying to get my HP MediaVault 2010 NAS working with Time Machine I thought I'd better get at least one good backup.

I plugged in the external disk that works perfectly with the MacBook, there's plenty of space on it, and the iMac Time Machine backup fails.

"The backup was not performed because an error occurred while copying files to the backup disk."

It then goes on to say that the problem may be temporary....try later....if persists use Disk utility to repair...

I'm beginning to suspect something on the iMac as one of the reasons for me using the USB disk in the first place is that after following the instructions to get Time Machine working with my HP MediaVault I'm getting exactly the same error message.

My iMac has the latest software the external disk works with the MacBook, what am I doing wrong?

Any help would be appreciated.

03-17-2011, 11:06 AM

Is the drive formatted to Mac OS X Journaled?

03-17-2011, 12:56 PM

My iMac has the latest software the external disk works with the MacBook, what am I doing wrong?

When you first setup Time Machine it was with the MacBook. Now you're wanting to use the same external storage for use on a different machine. Time Machine will naturally refuse because it recognizes that the machines are not the same.

What you need to do is partition the iOmega into two separate drives, one for the MacBook, the other for the iMac. Then setup Time Machine on the iMac to backup to the partition you created for it on the iOmega.

Or, buy a separate external hard drive for the iMac and use it for Time Machine.

03-17-2011, 01:59 PM

Originally Posted by chscag

When you first setup Time Machine it was with the MacBook. Now you're wanting to use the same external storage for use on a different machine. Time Machine will naturally refuse because it recognizes that the machines are not the same.

What you need to do is partition the iOmega into two separate drives, one for the MacBook, the other for the iMac. Then setup Time Machine on the iMac to backup to the partition you created for it on the iOmega.

Or, buy a separate external hard drive for the iMac and use it for Time Machine.

Hmm... at first look that makes some sense, however, the backup is just a file on the drive with a unique name made up in part from the computer name and its MAC address. There is no way either machine should get confused as to which backup belongs to which.

It would also mean that if I was using an Apple Time capsule to back up multiple MACs that it would also need separate partitions for each one.

That said I'll give it a go and get back to you. It won't take long to set up and can easily be changed back if it doesn't work.

03-17-2011, 08:06 PM

Hmm... at first look that makes some sense, however, the backup is just a file on the drive with a unique name made up in part from the computer name and its MAC address. There is no way either machine should get confused as to which backup belongs to which.

That's correct - which is why you need two separate backups if you wish to use the same drive for both the MacBook and iMac. Also, take a look at this thread posted in the Apple forums which may explain it better than I have.

LINK

03-18-2011, 04:07 AM

Originally Posted by chscag

That's correct - which is why you need two separate backups if you wish to use the same drive for both the MacBook and iMac. Also, take a look at this thread posted in the Apple forums which may explain it better than I have.

LINK

Problem solved.

I tried the separate partition thing on my USB drive and it didn't work, the MacBook backups still worked but I was still getting the same error from the iMac.

It turns out that the error message was not in any way vague or generic but exactly right!

I decided to tackle the problem head on. In my day job as an Oracle DBA the best tool for finding problems are the Oracle log files and the Unix/Linux system log files. Looking into the log files on the iMac I found the following error during the backup;


17/03/2011 14:05:23 com.apple.backupd[478] Error: (-41) SrcErr:NO Copying /Users/nick/Documents/Line 6/Tones/GearBox/Preset/Gold Bundle/Bass Expansion/1968 Groove.l6t to /Volumes/MacData/Backups.backupdb/Nick's iMac/2011-03-17-125757.inProgress/1B339453-383A-4BB0-A598-12E8A3C8B3F6/Macintosh HD/Users/nick/Documents/Line 6/Tones/GearBox/Preset/Gold Bundle/Bass Expansion

The file in question is a config file for my Line6 POD XT Live, an effects pedal for my guitar. The whole of the Line6 directory can be deleted as it was installed as part of the Line6 software on my Windows 7 PC and came over to the iMac simply because I copied the Windows My Documents folder complete with all subfolders over to the iMac. This folder will no doubt be recreated when I get round to installing the Mac version of the Line6 software.

I returned the USB disk to a single partition and ran the iMac backup again, this time it worked perfectly. I then plugged the drive into the MacBook and that also backed up without any problems. No need for separate partitions.

As the error was also the same as when I tried to use my HP MediaVault Network storage device I thought it likely that I'd fixed that issue too. I pointed Time Machine at the MediaVault and started another backup which was also successful.

Thanks to chscag for the help and pointers.

My next job today is to get the MacBook backing up wirelessly to the MediaVault rather than the external USB disk which can then be used as portable storage again.

For anyone interested in seeing exactly what their Mac is doing the log files can be accessed via the Console. To access it type console into Spotlight.

03-18-2011, 02:04 PM

Thanks for posting back. Certainly not an easy one to solve especially for for a user who does not have your level of expertise or experience. Good detective work!