Damn I wish I'd known this before deleting my TM drive. Still I had to change my computer name anyway so I wouldn't have been able to use it. It's a great hint though, thanks!

* IMPORTANT On my system at least *

When viewing this hint in Safari (4.0.2) the 'box' containing the instructions only shows 3 lines, the 3rd command 'sudo xattr -w.....' is missing - Firefox 3.5.1 displayed the page correctly!

Below is the complete set of instructions:

$ sudo fsaclctl -p /Volumes/Time Machine -d
$ sudo mv .00f9e8d7c6b5 .001a2b3c4f56
$ sudo xattr -w com.apple.backupd.BackupMachineAddress 00:1a:2b:3c:4f:56 Backups.backupdb/MyMac
$ sudo fsaclctl -p /Volumes/Time Machine -e

It works much better with the 3rd instruction - it certainly worked for me...

I fixed the problem; sorry about the rendering issue.

regards,
-rob.

"You need to re-pair the backup to the new logic board's MAC address."

By "re-pair", this hint author intends to say "re-associate" or, to put it another way, "reconnect".

Just a note in case that line confuses some readers, since "re-pair" might be interpreted as "repair". No criticism of the hint author's writing is intended.

This allowed Time Machine to resume backups again but it seems to have done almost a full backup instead of just the changed files.

From the log, it shows that 148.14GB was requested (the size of all data on my HDD) and 127.9GB was copied. I can be sure that no more than 5GB of files have changed since cloning the hard disk to this new computer. Don't know why it is still copying that much data over to the Time Machine backup though.

In the above commands, there are a few instances of "Time Machine" as an argument. As it's one operand, it needs to have the space escaped with a backslash to prevent the shell from interpreting "Time" and "Machine" as different operands.

For example, the "cd /Volumes/Time Machine/Backups.backupdb" should be correctly stated "cd /Volumes/Time\ Machine/Backups.backupdb" to work. It's a subtle difference, but Terminal is a subtle creature.

Thanks for the excellent hint and tutorial. I have that exact problem (a repaired MBP with a new logic board that I want to link back to my pre-existing Time Machine backups of its hard disk), and I'm sure your handy guide'll fix my issue, but I'm running into one stumbling block during the "reset the extended attribute on the backup store" terminal command, most likely do to my own ignorance.

My MBP's backed up hard disk (and therefore its backup's name) has a space in it: "JackBook Pro." Thus, looking at my backup disk in the Finder, you get the path: jack_machine > Backups.backupdb > JackBook Pro. (The FW800 Time Machine backs up to is named "jack_machine.")

When I type in the reset command and end it in "Backups.backupdb/JackBook Pro" I get the messages that the volumes "JackBook" and "Pro" can't be found. When I type it as "JackBook\Pro" as your addendum suggests, I get the message that "JackBookPro" can't be found. And finally, when I try "JackBookPro," similarly no dice.

Any thoughts on what I, an utter novice at Terminal use, am doing incorrectly would be infinitely and gushingly appreciated. Thank you. :-)

PS: Next time, I'm gonna not use spaces in hard disk names!

put any names in quotes:

'/Volumes/Name of a drive with a space in it/my files/etc'

OR

use a backslash in front of the space:
/Volumes/JackBook\ Pro/

either should work.

Spaces in terminal commands are a bit of a pain, be careful!

Thank you!

I got my backup back up and running, thanks to your advice (and the original hint too, of course).

I appreciate the help! YAY!

This HINT, although correct in its implementation, is unnecessary for the situation the Author states.

If you attempt to backup after the MAC address has been changed the TM backup will indeed fail and report it cannot found the TM backup volume. This is because the hidden file with the name of the MAC address (minus the colons) does not match the new MAC address.

All that is required here is to goto TM Pref panel and click on the "Change Disk..." button and reselect the TM backup disk and then manually force a backup via the Dock's TM icon "Back Up Now". The backup will now run and the new MAC address will be created as a hidden file alongside the old one. You can use sudo to remove this old one.

TM backup will proceed as it would have normally done without the MAC address change and without a deep traversal of all volumes that have not been excluded (as one person above experienced).

So as much as I applaud this HINT I have to say it's not necessary for dealing with a MAC address changing. However, it does alert people to the importance of the MAC address as it's used by Time Machine.

---
Regards... Barry Sharp

In my experience, however, following a logic board/MAC address change Time Machine will refuse to recognise the previous backups as belonging to the current system. After re-selecting the backup drive, it will just start a new backup set.

This hint allowed me to continue backing up in the same 'timeline' as the previous backup data. The only problem is that it seems to have forced a deep traversal and copied over most of the file system again.

Not so. It will recognise the earlier snapshots. Why would it not if the only association between the computer and TM is the MAC address. It simply does not make sense for it to be otherwise.

Have you verified using the TM browser that you cannot view or access the earlier snapshots - that is, the ones taken under the old MAC address ?

---
Regards... Barry Sharp

Yes, I've had the same problem quite a few times. Went through 3 replacement machines of identical configuration, each time Time Machine would initially report 'Backup Failed', saying it couldn't find the backup volume.

Re-selecting the backup drive would enable backups to proceed but Time Machine would create a new, separate backup instead of continuing on from the previous backup data.

Yep - I ran a few tests on this scenario and you're correct. I was not able to figure out just how to fake TM into continuing on from where it was. It does always make a new FULL backup. :( Bummer.

---
Regards... Barry Sharp

TM will make a full backup if it cannot trust the backup volume's TM management data. I suspect if you used the HINT as posted here that what you did was insufficient to convince TM that things were as they should be. Hence TM will protect user by doing a full backup as a safety precaution.

---
Regards... Barry Sharp

I followed the process outlined in this hint, then also set "use this disk for backup" in the time machine preferences. Now, new backups appear to be going to the right place (ie, continuing the old backup store), but in "time machine view", it appears as though nothing is backed up. No mater which folder in the finder I'm looking at when I enter time machine, the view switches to the "computer" (ie top-most level) view.

If I use 'tms', files are shown as existing only in the latest snapshot.

Any ideas? I'm concerned that there might be a deeper problem, and just starting a backup from scratch may not fix it. Ideally I'd like to have my backup history back...

DRM

I am planing to something which seems will run into this very problem. I am getting a new Mactel computer. I am running Leopard on a PPC machine off an external Firewire drive. I was planning to just move the external drive between the computers which will be housed at different locations and run the same system on both computers, thus keeping them in sync with the least hassle. But from this thread it appears that I will have problems with Time Machine because I will be using two different computers which I presume will have different MAC's. Does this mean that I will either just have to abandon Time Machine altogether; or use two separate Time machine volumes, one for each computer and all the needless duplication of files that this will entail?

TM is tightly coupled with a specific Mac. If you have two Macs and one External HDD the one HDD can be used by both Macs but there will be two TM folders created - one for each Mac. TM will know which one is associated with its machine so there's no worry there.

The OS for the PPC and Intel-based Macs are different so you don't want to sync the TM backups between them. Treat them separately is my advice.

If you want to sync user data between both Macs use the .Mac sync-ing feature as best you can. There are other ways for sync-ing user-level data between machines also.

---
Regards... Barry Sharp

Actually, as of Leopard, it's quite easy to build a system that works for both architectures and has a complete installation.

1) partition a drive in the GUID style
2) install Leopard using an Intel Mac
3) clone installation to an APM-partitioned drive

What happens when you run Software Update, or any kind of installer or other updater, on such a universal drive? Can we assume that all updaters and installers will be available in a universal version, and if so, that Software Update will automatically install a universal version? I'd be concerned that, when the drive was connected to an Intel Mac, that at least for some updates, at least in Software Update, Intel-only code would get installed, with no option given to the user to make a choice, and the equivalent/reverse would happen when the drive was connected to a PPC Mac. If this is so, this would still argue for the use of two separate volumes on an APM-formatted drive, one for Intel OS X, and one for PPC OS X.

You should be able to have a single Time Machine backup (as per your comment below) but you may want to consider having a separate backup at both locations - that was you'll always have an "off-site" backup that's current.

I don't have a .mac account and I don't plan on getting one any time soon so syncing via .mac is not an option. I have backups to Time Machine run every 6 to 12 hours, so it just occurred to me that I only need to run Time Machine from one of the computers, the one that I am at the majority of the time. Since I am using the same startup Volume on both computers, that should keep Time machine current enough for my purposes.

This is the beginning of something good, but I don't think it quite accomplishes what it hopes to do. I followed the instructions to the letter, but when Time Machine started backing things up, it backed up the entire disk. This seems to be what others have experienced as well.

My situation is a bit different, though. I got a new computer and migrated my settings from the old to the new. These are all the same files (except the system files, perhaps. I went from a PPC mini to an Intel mini) but since they have been copied over they have new inodes. The paths are still the same.

Nonetheless, I was hoping to use the old backup as a starting point. Though I am able to restore from older files, my backup archive has doubled in size because Time Machine thinks every single one of my files has been changed.

That can be a serious issue, but I have a feeling that fixing it would require a much deeper understanding of FSEvents than I have been blessed with. If you've got any ideas I'd love to hear them.

If you feel comfortable about deleting the older backups (ones prior to making the computer switch) then much of the increase in TM backup space could be reduced.

Post back and say if the new FULL backup created a new folder for the backup snapshots.

---
Regards... Barry Sharp

I have a different situation coming up. I want to move my Time Machine Backup to a LARGER hard drive. If I name the hard the same and clone the old TM backup drive to the new one, will my MacBook Pro continue to backup to it using the same data/folder?

FYI...
A Leopard compatible SuperDuper (SD!) is very likely to be released very soon. This new SD! version will allow you to clone your current TM backup/snapshots data to a larger Volume and continue on without a FULL backup being necessary.

---
Regards... Barry Sharp

I recently had to put my primary computer in the shop, and I was temporarily booting my laptop with my external system. I wanted to keep making backups, so I followed the procedure above. It worked, and I was able to keep making backups, but when I tried to switch back to the original iMac, I followed the procedures to return to the old settings but now the only way to bring up the old backups is to browse the drive. The trouble is I don't know if it's because the procedure doesn't work in reverse, or the fact that I didn't try until after I updated to 10.5.2. I suspect something changed in the new version of Time Machine, and some metadata isn't updated so that it automatically recognizes old versions. Fortunately, it claims to still be doing backups, and when I check, the versions are there. Unfortunately, it takes an extra step to get to them.

Just a heads-up, in case someone has done this and is now seeing problems.

This hint worked (almost) perfectly...
In my case, I also had to change the name of the machine by renaming the Directory
sudo mv <old machine name> <new machine name>
after this and the remount of the drive Time Machine showed all the history.

BUT...

I had used TM on a machine where I had previously installed Leopard including using the migration assistant to transfer users from Tiger. On another post this topic is covered with a method for replacing the GROUP that gets lost in this migration process. Now on the newest machine, I'd already followed those instructions to replace the unknown "?" group with the standard Leopard group "staff". When I called up the Time Machine, I could see in the history that the group information from the older backups didn't match my current settings. I'm relatively sure that this is the reason why TM then tries to backup practically all files fully instead of incrementally, since the access to the previous backup is denied.

Comments appreciated - Does Apple know about this?

Help !!! - BarrySharp/DethBunny nd whoever else - as a novice mac user and with computer's in general, I have tried dethbunny's original solution of 1 feb 08 but it does not seem to work - I suspect I am doing something wrong in terminal. By way of history, I had my logic board replaced and then time machine would no longer work. I re-selected my backup drive in the preferences area and then it did a new full backup. So, when i open my backup drive, I can see the old set of backups (named Nicholas Wenck's Computer) and the new set of backups (named Nicholas Wenck's Computer 2). However, I cannot see the old backups in time machine and hence cannot restore from there. In all the threads I have read, it is now not clear to me what the solution is. I simply (perhaps not simply at all) want to be able to see and use the old backups in time machine. I am happy to get rid of the new backups (especially to free up space on my backup drive) as there is nothing significant there I need that will not be in the old backups. Please help

---
Nickw

In your case there should not be a problem in getting access to your old TM backups performed on your computer withy the older motherboard.

For example, I have a PowerMac G5 and a MacBook Air and both are running 10.5.2 and backup to their own TM backup disks/volumes.

I can connect my MacBook Air's TM backup disk to my G5 and using the Dock's TM icon select to "Browse Other Time Machine disks...". Doing this I can then select the MacBook Air's TM backup disk and browse all of the backups and restore files to my G5 if I so decided.

You can do the same thing as I explained abovDefine a new partition, disk, volume etc for your new backups while leaving the old ones alone. Following what I wrote above now select/navigate to your old TM backup disk and do your restores.

---
Regards... Barry Sharp

BTW - you can use SuperDuper! version 2.5 (it's Leopard compatible) to clone your old TM backup volume to some other volume if that helps you.

In fact you can place a TM backup volume/folder onto a Cloned Leopard boot volume. I do this by first cloning my Leopard boot volume to a disk and then place my TM backups onto the same disk. The system will boot up happily even with the TM backup folder on it. Makes sense as you can place TM backups onto your internal boot volume if you so desire and system boots up without issues.


---
Regards... Barry Sharp

Well, I finally took possession of my Mac mini Intel. I had no problems using the external firewire volume that I had been using as the boot volume on my PPC mini, although I had to boot a second time to get it to settle in. I did have to setup the bootcamp volume on the GUID internal disk, but since you have to reboot to get into Windows that is nothing. I will be curious if Parallels or Fusion will allow me to use the external, AFP volume and I will be on the lookout for any problems with software update being unable to install on a AFP volume, but I suppose that updating when the system is booted into the PPC will work.

I did successfully, as far as I can determine, change the MAC address on the Time Machine volume to continue the Time Machine backups, but anyone doing so must realize that you must escape the space in the Time\ Machine name when you use the terminal.

Thanks for the hint, and I will report any future adventures.

It should be noted that when TM backs up to a net HDD such as the Time Capsule a sparse bundled disk image is created on the TC's HDD. The name of this image contains the Computer Name and the computer's MAC as well as the hidden file '.MAC'. For example on my Time Capsule I'm backing up three Macs and the sparse bundled disk image file names are (N.B. I've replaced the actual MAC with a bogus value such as "MBA's MAC").

Barry Sharp's MacBook Air_MBA's MAC.sparsebundle
Barry's PowerMac G5 (2)_PMG5's MAC2.sparsebundle
Gillian Sharp's MacBook (4)_MB's MAC.sparsebundle


---
Regards... Barry Sharp

This HINT needs to be updated to include what needs to be done if one has been using the Time Capsule for TM backups and the Mac being backed up undergoes repairs such that its MAC address changes. The TM backup structure on the Time Capsule's internal HDD is different from that on a TM backup disk that is directly attached to the Mac. The original HINT address ONLY the case for the direct attached TM backup disk.

The TM backup on the Time Capsule is a sparse bundle disk image and few more things have to be taken into account. I've gone thru this and successfully dealt with a MAC address change but need to formalise my notes before posting what I did. If someone beats me to it, then be my guest. Thanks... :)

---
Regards... Barry Sharp

$ sudo fsaclctl -p /Volumes/Backup\ of\ MyMac -d
$ sudo xattr -w com.apple.backupd.BackupMachineAddress 00:1a:2b:3c:4f:56 /Volumes/Backup\ of\ MyMac/Backups.backupdb/MyMac
$ sudo fsaclctl -p /Volumes/Backup\ of\ MyMac -e
$ cd /Volumes/Time\ Capsule
$ sudo mv .00f9e8d7c6b56 .001a2b3c4f56
$ sudo mv MyMac_00f9e8d7c6b56.sparsebundle MyMac_ .001a2b3c4f56.sparsebundle

You are the Winner!!! Thank you so much for your excellent work! This worked for me. I had a mac mini fail, and I wanted to just use another mac mini to replace it in every respect, including the backup-timeline. This worked, thank you!

Ignore my previous comment - I left off the -d on the first command.

Got as far as the cd command when I got a
permission denied

Can anyone help? This only half worked for me...

I got a new machine and transferred all my files and settings, so I ran into this same problem with my previous backups. They weren't showing up in TM, and it created a new folder MyComputer 2 instead of continuing to use folder MyComputer.

I followed these instructions and was successful in renaming the hidden system ID file and reseting the BackupMachineAddress attribute. I can now see my old backups in TM. However, for my next scheduled backup, it still created a new folder MyComputer 2 and copied my entire hard drive into it. I can't access these latest backups in TM -- it only shows the old ones in the MyComputer folder, not any of the newer ones it has been creating in MyComputer 2. I went back into Terminal and checked what the BackupMachineAddress attribute was for both folders, and they are the same (the correct, new MAC address). There is just one hidden file still and it is also correctly named with the new MAC address.

Of course, ideally I would like to access all my backups through TM, but at this point, I would be happy just going back to being able to access my most recent backups through TM and the old ones from my previous machine through the Finder, since eventually I will just delete those to free up the space.

Can anyone help?

I had similar problems. After following the steps in the hint, time machine would still create a new directory when backups began. My solution was to move the contents of the old time machine directory into the new one. To do this (I believe) I used terminal to move the old directory to the base of the time machine drive, then finder to move all its subdirectories to the new directory. After I started the backup again, it renamed the new directory as the old directory and is now proceeding with a large backup (1/3 the size of my HD contents). Hope this helps.

On a related note, AppleCare told me to just restore from the backup. This didn't work, and since they didn't remind me (or I didn't remember) to backup my TM excluded files, I lost them. Way to go, AppleCare.

This also worked for me, but even easier. I simply moved the "old" files to the new "mymachine2" folder (system required that I authenticate) and everything worked fine. I am now accessing and updating the old backups as if nothing ever happened....

I went through this, and was still getting Time Machine attempting to back up EVERYTHING. I kept trying, and couldn't figure it out.

Then I had my "aha" moment. I went and looked at the folder where TM keeps the backups, <YourTMDrive>/Backups.backupdb/, and saw that there was BOTH my original backups folder <mymachinename>, and the new folder, <mymachinename 2>. The exact same folder name, with the number (2) appended to it, with a space between.

I deleted the folder <mymachinename 2>, told TM to backup NOW, and it appears to be going to work!

Hope this helps. BTW, I had gone to the local apple store, and they emphasized that Apple does not support this. The Genius's suggestion, which I must admit would have been good, was to have installed Leopard, and then imported data from the TM backup. I guess that would have BOTH setup the machine with the old data, and converted those old backups to be pointed to this new machine.

Lastly, it finally dawned on me what the original author meant with his post - not "repair", but "re-pair", as to re-associate the backups with a different logic board or machine! Ah, the power of the hyphen!

Well, to continue the saga - after many hours, TM backed up my new machine to the original archive(s) which had been created by/for/with the original laptop.

HOWEVER, it still said it needed to backup over 100 gigs of data. Not everything on the machine, but an awful lot. So, it deleted the older data to make enough room for the new backup. Which is happening as I'm writing this.

I guess it's good that I got them all "together", however, I'm a little perplexed as to why it thought it needed to backup so much data that should've already been there. (Remember, this drive was created by cloning the original laptop drive with Carbon Copy Cloner.)

(Moved from the wrong place)

I followed the process outlined in this hint, then also set "use this disk for backup" in the time machine preferences. Now, new backups appear to be going to the right place (ie, continuing the old backup store), but in "time machine view", it appears as though nothing is backed up. No mater which folder in the finder I'm looking at when I enter time machine, the view switches to the "computer" (ie top-most level) view.

If I use 'tms', files are shown as existing only in the latest snapshot.

Any ideas? I'm concerned that there might be a deeper problem, and just starting a backup from scratch may not fix it. Ideally I'd like to have my backup history back...

DRM

The subsequent backup, at least the first one, took a very long time to prepare (like maybe 10 or 15 minutes) but I was patient and now it appears to be doing an update to the old backup tree. Awesome. So we'll see how it goes and if I can indeed browse through my windows like before my logic board was replaced. I'll reply to this comment when I know the answer. It doesn't look like this 1.9 GB update is going to be done very soon. I don't know how big my updates have been lately, but it's been 10 days since I brought the Mac back home from the store and I haven't had a chance to look at this since then.... so 2 GB over 10 days is reasonable.

Thanks a LOT for this hint. I found the hidden file with the ethernet Mac address and thought that was all there was to it. I would probably have given up on my old backups before finding the additional xattr stuff. Awesome.

[ Reply to This | # ]

When I first tried this, as I said in the previous post, I got the MAC address wrong in the xattr command. And the result was that it would have backed up my system, but in a directory named the same as my original directory, with a 2 added. So "Foo Computer 2" instead of "Foo Computer". This was not acceptable AND I don't have enough space on the external drive to back up the whole thing again.

Having gone back and checked and rechecked my work, I got it to work as expected and as advertised. The 1.9 GB incremental backup succeeded and I'm able to browse through all of my backup data in the Time Machine wormhole interface. Yee-hah. And I just forced a second manual backup to verify that everything is fine and it's doing small incremental backups again. All is well.

Thanks again!

[ Reply to This | # ]

If you are not so familiar with handling extended attributes, this variant might be simpler to understand and remember:
1) reselct the backup volume with Time Machine system preferences and start a Backup, and stop it after a few seconds again. Time Machine will have created a new backup folder within Backups.backupdb on your TM volume with the correct xattr settings. Assuming the old and new system have the same name, the folder will be named "system-name 2".
2) disable xtended attributes
$ sudo fsaclctl -p /Volumes/TM/ -d
3) change to your new back folder and move the old backups here
$ cd /Volumes/TM/Backups.backupdb/system-name\ 2
$ sudo mv ../system-name/* .
3) it will complain with the message "mv: rename ../system-name/Latest to ./Latest: Operation not permitted". As a remedy, recreate the symlink after displaying the original value:
$ ls -l ../system-name
lrwxr-xr-x 1 root staff 17 May 14 20:00 Latest -> 2008-05-14-200044
$ sudo ln -s 2008-05-14-200044 Latest
4) do the clean-up
- remove the old backup directory and mv the new one to the old:
$ sudo rm -r system-name
$ sudo mv system-name\ 2/ system-name
- remove the old MAC-address from the root directory
- remove the in-progress folder from step 1
5) re-enable extended attributes:
$ sudo fsaclctl -p /Volumes/TM/ -e

Credit to the original hint!

This alternative indeed might provide some additional background to the original hint. Thanks for that!

However, I think this alternative is much more prone to serious problems, especially as it claims to be written for those "not so familiar with handling extended attributes".

What's so difficult in using sudo xattr -w ...? If that is too difficult, then please consider that making a mistake using the alternative one might loose all data, either on the Time Machine disk, or maybe even on the internal harddrive! The original tip does not include potential very dangerous commands such as sudo rm -r system-name.

I'd advice to follow the original hint, or take a look at 10.5: A script to fix Time Machine after hardware repairs.

I just got my MacBook Pro back yesterday after having the logic board replaced and am trying to get my Time Machine backup reconnected. I keep getting locked up in the second Terminal command:

xattr -p com.apple.backupd.BackupMachineAddress MyMac

I've entered every conceivable version of my computer's name that I can think of, but it always tells me that there's no such file. What am I missing? I'm assuming this should be the same name as that listed in the "Sharing" section of the System Preferences?

Thanks for the assistance!

Did you run the previous command, "cd /Volumes/YourBackupDisk/Backups.backupdb"? The machine name in the xattr command refers to a directory that exists under the Backups.backupdb directory in your backup disk, so if you are not in the correct directory in the shell, it will not find it.

As an alternative, you can do it all in a single command: xattr -p com.apple.backupd.BackupMachineAddress /Volumes/YourBackupDisk/Backups.backupdb/YourMachineName

Hey,

I'm also stuck at this place. Once I enter my computer's name at the end of the command, I receive a blank command line that when I enter additional commands in, nothing happens. Help please?

This is a great hint, and very useful. When I send my work machine for repairs I get a spare one, to which I duplicate my disk using Disk Utility. This hint allowed me to continue using the same TM backup set, keeping my backup history intact. Thanks!

I upgraded my macbook by swapping the drive from the old one into the new one.

This hint helped me resume my backup, where it left off. I have over 210GB to save, and the first backup after completing this hint is 33GB (which is about right).

Thanks!

I'm a bit of a mac novice ( so much so that I didn't understand that I needed to take out the $ at the beginning of every line ), but I eventually worked my way through the hint.

It seems to have half worked on my system. When I ran TM it backed up into my original folder (rather than making a new one with a '2' suffixed on), and it seemed to perform an incrememtal backup rather than a full one (it backed up about 12gb, rather than 60gb - which sounds right to me). All seems fine and dandy thus far.

The problem comes when I explore my backups. When I click 'Enter Time Machine' I can only see the backup that I have just made. If I want to see an older backup then I need to select 'Browse Other Time Machine Disks' and then select the disk that I'm already backing up to.

I'm somewhat flumoxed, please help

Rob

Thanks a lot, this worked great.

I copied/pasted the four shell commands into TextEdit, then edited to fit my ethernet addresse and system name. That also resolves the issue that the third command (xattr) appears mangled in safari.

Mount/unmount via Disk Utility was not enough for my system to recognize the new drive, I had to unmount it and physically unplug the drive, then plug it back in.

But now it all works - thanks so much for this tip!

Apple should really use the system's serial number rather than the ethernet MAC address as a unique identifier.

Apple should really use the system's serial number rather than the ethernet MAC address as a unique identifier.

i'm sure this works for the majority of Time Machine users, however i am an Airport Extreme Base Station (AEBS) user with attached USB hard disk. I am encountering the same problem as people with Time Capsule.

Please, somebody help ! lookin at you BarrySharp.......

thank you.

Okie one more qustion
What if your computer name is Wee Eu Ann, Jermyn
There are two spaces between Wee and Eu, and there is a comma
for some reason it says cant find the file when i use

Wee\ \ Eu\ Ann,\ Jermyn

Help would really be appreciated!
Thank you

     'Wee  Eu Ann, Jermyn'

---
-- Joshua Yeidel
Center for Teaching, Learning, and Technology
Washington State University
Pullman, WA, USA

[ Reply to This | # ]

After a fatal HDD failure, I replaced my MacBook's internal drive with a new one. I then restored al my stuff from an external TM backup. (Everything worked very smoothly here, Leopard rocks really hard.)

I then tried to pair again the external TM drive with the "new old" system, by simply selecting it in the TM pref pane.

After this, TM first scans the entire drive and then reports that there isn't enough space (70GB to backup, only 30GB free on the TM drive) . It's obviously trying to create a new full backup on the TM drive, instead of re-binding the old one to the system that was actually restored from it.

So, what I believe is that there another parameter than the MAC address.

Any suggestion would be appreciated.

Thanks!

Hi,

Thanks for posting this Hint. My PowerBook has recently (Oct 2008) undergone Logic Board switching and following the steps described in the Hint enabled me to have Time Machine backing up in the original Backup folder of my External HDD.

There is one problem though: although I can access all my backed-up files through Finder, I am unable to do that when I'm in the Time Machine Starfield Interface. When I click on the "Enter Time Machine" command, I can correctly get inside the TM starfield interface but I'm unable to go back in time. The only active Finder window displayed is the front-most one and displays only what is in my PowerBook hard drive in the present. In the back, empty dark grey finder windows are displayed. Clicking on the back button does nothing and the timeline only shows Now/Today. What is strange is that when I go to the Time Machine Preferences Panel, it shows that my oldest backup is in Nov 2007, which is almost a year before I had my Logic Board switched.

So, there seems to be no problem writing new backups in the folder that contained all my old backups, but TM is unable to display any backup in the starfield interface. I know that I still can access the backups through Finder, but I really like the starfield mode and want to be able to use it for its ease of use. Does anybody know how to fix this?

Thanks for your help.

I have performed this re-pair'ing twice on the same machine. Once back in June with whatever was current Leopard at the time, and then again at the beginning of October. In both cases the backups are correctly going to the existing backup tree.

Since the October re-pair'ing I'm experiencing the same behavior as far as 'Show Time Machine' (only shows present), Select Other Time Machine Disk... (shows all backups), and Time Machine Preferences... (shows correct oldest backup date).

One other difference between the June re-pairing and the October re-pairing is that in June it picked up with just the needed incremental backups, but in October it performed what was likely a full backup (got message that it was deleting the oldest full backup to make room, and then it backed up an equivalent size to the data on the boot drive).

I believe that the machine is being properly backed up, and the backups appear to be accessible via the "Select Other Time Machine Disk..." but it would be nice to understand why "Show Time Machine" is not working properly.

I was having the same problem and, following a guide elsewhere, reformated and repartitioned my backup drive. TM will not backup to this drive at all now, throwing up the 'drive not found' error - it does not even get as far as preparing the drive. So consequently none of the files mentioned in this guide exist on the machine in question. TM will not back up to any other external drives either. Anyone have any idea what I can do to get it up and running again, as it's a great tool when it works.

I tried this, following all the steps but it doesn't work. I've noticed that after the 'sudo mv .00f9e8d7c6b56 .001a2b3c4f56' step (using my own numbers) the files haven't changed. There is no new file name. What would cause this?

I'm with you on this. I have tried this EXACTLY, and it doesn't work. It always starts a NEW backup folder "macelvis 2" in the backups.backupdb folder.

Any hints here people? Seems a really really crap-ass backup program if a logic board screws it up so damn badly.

I discovered my problem...which could affect others as well. When I was doing this...I was using the mac address given to me by the system profiler...but this was for MY WIRELESS/AIRPORT CARD..not the hard-wired ethernet connection....which I presume is the address of the new logic board. So I used the ethernet card mac address as given to me by selecting it in the network system preferences.

Have just been trying this, but have gotten stuck at the :

cd /Volumes/Time Machine/Backups.backupdb

part - the volume / directory isn't known apparently. Is that a standard name, or might it be called something else?

I'm wondering if its because the Time Machine disk needs to be mounted, and is where I'm unsure. The Time Capsule appears in the Finder under Shared, but should I be able to see a Time Machine disk as well, that would have that volume?

OK - made a bit of progress, as far as the

$ sudo mv .00f9e8d7c6b56 .001a2b3c4f56

line - again getting 'No such file or directory' error. (and yes, I am using my MAC addresses...)

Just as I thought I was nearly there!

A long story for the sake of Google et al:

• On my MacBook, which uses its built-in AirPort to connect to an AirPort Express (which is then wired to a Mac Mini, to which a USB disk named "TM" is attached for Time Machine) actually the MAC-address of the ethernet port is used (though not active!), not the Mac address of the built-in AirPort (which is active). In fact, it's easy to tell: temporary rename all the dot-files and you'll see that Time Machine creates a new one for the MAC-address it's using (and on my Mac, the timestamp of that file is always June 15 2008).

• I removed the password while my MacBook was in repair, and when sudo prompts for the password then hitting Enter (for an empty password) seems to cancel the sudo command without any error...? Setting a password again solved that issue. So, always validate that the new MAC-address was set: after "sudo xattr -w com.apple.backupd ..." always run "xattr -p com.apple.backupd ..." again!

My MacBook was in repair for quite some time and meanwhile I had restored the Time Machine backup to the Mac Mini. On that Mini, I used to have a guest user with the very same name of my MacBook user, just for the backup. This made the restore to the Mini a bit cumbersome (restoring a user account which already existed as a limited account...), but I managed. However, when the MacBook returned home it only had read access to the opened sparsebundle (now that I am writing this: maybe that is because that Mac Mini user now also has an empty password -- can't verify that now). This caused some problems after taking the steps from the above hint:

• When manually mounting the remote disk using the new credentials then after "Network mountpoint /Volumes/TM not owned by backupd... remounting" I would get "[SnapshotUtilities remountVolumeRef] url could not be resolved via BonJour", "Failed to remount network volume", "BackupCore -- _CSBackupServerProxyCopyDestinationMountPoint returned: 19" and "Backup failed with error: 19".

• Manually mounting using the new credentials, and then setting up Time Machine to use that volume for the backup, would make no changes.

• When not manually mounting the disk, then choosing "Backup now" would give me "FSMatchAliasBulk returend -5032 while resolving alias to backup target".

• In all cases Time Machine itself would not show any history (it would only show Today).

So, I backed up the sparsebundle and then opened the sparsebundle myself, and changed the access rights for "staff" or even "everyone" to "read/write". Running those changes took over 24 hours to complete, and did not solve the issue.

But the solution was simple... To tell Time Machine to use other credentials one needs to clear the network passwords in Keychain -- but until today I did not know that in Keychain's menu View there's an option "Show Keychains", which is required to allow for selecting "System" (it defaults to "login") when searching for the old passwords to change (or simply delete to be prompted for new credentials)...

After that Time Machine showed the full history again, and running "Backup now" got me "Event store UUIDs don't match for volume: Macintosh HD" (which I don't understand) followed by "Node requires deep traversal:/ reason:kFSEDBEventFlagMustScanSubDirs|kFSEDBEventFlagReasonEventDBUntrustable".

Seems to work fine now!

If my computer name was saved as:

William McKendree's Computer

how would I enter that in terminal? I've tried "William McKendree's Computer" but and several variations, but it keeps telling me there is no such file.

Thank you!

Nevermind, I got it after all! I just discovered the "Paste Escaped Text" option in the edit menu which will do that for you.

Which MAC Address should be used? Built-in Ethernet, AirPort? I've tried both and when I try a backup it says:

"The network backup volume could not be mounted because there was a problem with the network username or password."

As stated in a previous comment on this very page:

On my MacBook, which uses its built-in AirPort to connect [..] actually the MAC-address of the ethernet port is used (though not active!), not the Mac address of the built-in AirPort (which is active).

And:

To tell Time Machine to use other credentials one needs to clear the network passwords in Keychain -- but until today I did not know that in Keychain's menu View there's an option "Show Keychains", which is required to allow for selecting "System" (it defaults to "login") when searching for the old passwords to change (or simply delete to be prompted for new credentials)...

Does this work for you as well?

Not needed for this tip, but maybe helpful for troubleshooting: the content of the hidden .00f9e8d7c6b56 file on the backup drive should match the contents of the file /var/db/.TimeMachine.Cookie on the computer.

If not, then one will see:

/System/Library/CoreServices/backupd[12825]
  Backup destination mounted at path: /Volumes/TM
/System/Library/CoreServices/backupd[12825] 
  Volume at path /Volumes/TM does not appear to be the correct backup volume for this computer.  (Cookies do not match)
/System/Library/CoreServices/backupd[12825]
  Backup failed with error: 18

It seems that selecting another drive for Time Machine (through System Preferences) might change the timestamp and contents of /var/db/.TimeMachine.Cookie as well.

I wish I had seen this comment an hour ago. I missed one step of the process (renaming the sparse bundle) and so Time Machine attempted to create a completely new backup and failed due to limited space. When I corrected that, it seemed to start okay, but has been sitting here for a long time with no progress. Turns out, I think the previous failed update modified the cookie ... so it has to do some sort of "deep search". For hundreds of GB that could take a while (especially since I am doing it over WiFi).

Anyway, if anyone else messes up first, make sure you keep this part in mind before fixing any issues and moving on!

Another side note, just for the archives: one can easily use multiple drives for backup.

I am not using Time Machine for disaster recovery only: since I have learned that Time Machine has a perfect integration with Apple Mail (and Address Book, and iPhoto '08) I really like being able to go back in time. However, I am a bit too lazy to set up a (rsync, ...?) backup copy of my Time Machine drive. So, I swap two USB drives every now and then -- thus keeping that weekly backup even if one of the drives fails or is somehow erased.

To make that work without the need to select a different drive in the Time Machine preferences each time you swap the drive: just make sure that all drives use the very same contents of that .001122334455 cookie file, and of course match the file /var/db/.TimeMachine.Cookie.

I did NOT try this with attaching the drives to the MacBook directly: in my set up, both drives also have the same name, and I attach them (one at a time) to a Mac Mini -- so Time Machine on my MacBook always uses the same AFP share name. The second drive initially was a full copy of the first, to preserve existing history.

When the CONTENTS of the hidden .001122334455 files do not match, one will get the "Volume at path [..] does not appear to be the correct backup volume for this computer. (Cookies do not match)" error I mentioned in my previous comment. At that point one could still continue using that drive by manually selecting it (which would not create a new full backup then, assuming the file NAME of the .001122334455 file matches the MAC address, even though the file CONTENTS do not match /var/db/.TimeMachine.Cookie). Ensuring that the contents match as well, eliminates the need to manually select another drive.

When in need to restore a file that only existed for a short period, I might need to search both drives, but well... In fact, I never investigated if the weekly backups (which are kept until the drive is full) do hold all files that ever existed during the daily backups of that week -- I guess not?

(As per the original hint, it is of course not sufficient to have a file name that matches the MAC address, and contents that match /var/db/.TimeMachine.Cookie, to make a drive being used for a specific computer. The extended attributes must be set as well. All of these will be fine when copying an existing backup onto a second drive.)

See also 10.5: Use multiple Time Machine disks for redundancy

As for the 10.5: Use multiple Time Machine disks for redundancy hint mentioned above: be sure to read its comments for more insight about, for example, the extended attribute com.apple.backupd.SnapshotVolumeLastFSEventID. Ars Technica also features a well-known technical article, explaining how Time Machine uses the logs maintained by fseventsd.

And for whoever is reading these comments (about using multiple drives) through deep links posted on some other sites: please note that these comments are part of a much longer story: 10.5: Repair Time Machine after logic board changes. (Reading the whole story you will learn many more details, like how you might run into "Volume at path /Volumes/TM does not appear to be the correct backup volume for this computer. (Cookies do not match)", and like selecting another drive for Time Machine (through System Preferences) might change the timestamp and contents of /var/db/.TimeMachine.Cookie as well.)

If you initially want to clone a drive to get your second backup drive, then see A Bigger Time Machine without Changing History.

Hi

Need a bit of help. I changed the MAC address file fine, but when enabling Time Machine I get a permissions error "you don't have permission to change the file '.MyMacAddress' in folder 'Time Machine' ".

The permissions settings for the file are listed as:
-r-------- 1 root staff

Looks like read only. How do I change this?

Thanks, worked like a charm.

How did that help you? My computer's name is:
Pico's Computer
When ever I type it in a line for teh terminal it doesn't work.

Try to use double quotes, like: "Pico's computer"

Alternatively, try to "escape" both the single quote and the space, like: Pico\'s\ computer

Just FYI, I had my logic board replaced recently by Apple. The serial number that shows up under Hardware in System Profiler is the same as the serial number on the sticker under the battery. My guess is that the procedure for replacing the motherboard is supposed to include copying the serial number from the sticker into some machine-readable location (EEPROM or something), but the procedure isn't followed exactly every time.

---
-- Joshua Yeidel
Center for Teaching, Learning, and Technology
Washington State University
Pullman, WA, USA

drwxrwxr-x  7 stasminsker  staff    510 Jul  6 20:20 .
drwxrwxrwt@ 5 root         admin    170 Jul  6 21:56 ..
-r--------  1 stasminsker  staff     16 Nov 13  2008 .001122334455
-r--------  1 root         staff     16 Jan 24 14:30 .aabbccddeeff
-rw-rw-r--@ 1 stasminsker  staff   6148 Jul  6 21:48 .DS_Store
drwx------  3 stasminsker  staff    102 Nov 13  2008 .Spotlight-V100
d-wx-wx-wt  3 stasminsker  staff    102 Jul  6 21:56 .Trashes
-rw-r--r--  1 stasminsker  staff      0 Nov 13  2008 .com.apple.timemachine.supported
drwx------  2 stasminsker  staff  37298 Jul  6 21:57 .fseventsd
drwxr-xr-x+ 3 root         staff    102 Jul  6 21:19 Backups.backupdb

when i type in
sudo xattr -w com.apple.backupd.BackupMachineAddress 00:1b:63:a0:70:96 /Volumes/SweetieBackup/Backups.backupdb/Sweetie

i get this error
[Errno 1] Operation not permitted: '/Volumes/SweetieBackup/Backups.backupdb/Sweetie'

what's wrong?

tried to get around the permissions problem by using finder (with hidden files shown) - renamed the hidden .MAC file and the sparsebundle.

I can now enter time machine but it shows no backups. However, if I Browse Other Time Machine Disks I can access the backups.

I suspect this means if I do a new backup now, it will do a full backup, not an incremental one.

it's nice to get access to the backup - but any thoughts about how to actually pair them up for real?

As I usually change my hardware once in a year: Why isn't there a programm/script in the market that does exactly what is described here? I would spend 10 bucks for it and probably others too.

Regards,
hartmut

Because it only applies when you keep the same harddisk?

(A script for the abovementioned instructions exists, see 10.5: A script to fix Time Machine after hardware repairs.)

ifconfig en0

I have TM backing up to Time Capsule through an ethernet network and wirelessly. I attached to my network though ethernet and attempted these commands as given. It hung up on the change directory (cd) command (operation not permitted). Will the system really allow me to change the directory to a network drive as indicated? Skipping this line, I specified the whole route and entered the next one as:

$ sudo mv /Volumes/Time\ Capsule/.00f9e8d7c6b56 /Volumes/Time\ Capsule/.001a2b3c4f56

A similar transform on the next line did not work (though the problem could be a typo in the example). It occurred to me that I could just change the filename in the Finder (MyMac_00f9e8d7c6b56.sparsebundle became MyMac_001a2b3c4f56.sparsebundle). Now when I re-ran TM, it "re-paired" my machine with its previous incarnation. Backups are now functioning normally.

Install Snow Leopard. It should fix this problem.

Why should Snow Leopard fix this? Did Apple include some GUI to get this done?

Firstly I want to thank the original post, because it worked just fine for me!!!!!!!

Just wanted to add something small to the original post... I am not very familiar with terminal instructions and all that, so I was just blatantly following what was written on the post. I did everything and it didnt work. I nearly gave up, but then I got one last idea which was to go into the Backups.backupdb folder and have a look.... There were 2 folders in there. One was "system name" and the other was "system name 2"... Just to give it a try I deleted the "system name 2" and now it is working fine...

Hope this helps... Thanks again to the original post!!!!!!!!!

Hello -

I followed the hint listed above, making adjustments for volume names that needed to be enclosed in quotes, etc. Nevertheless, when I unmounted the volume by rebooting the machine, the Time Machine interface offers me only the backups that have been done since the MAC change (from the logic board swap). Have I just lost access to months and months of backups? Is the problem that I let TM complete a full backup using the new MAC before realizing that that was the source of the problem?

All commands seemed to have executed correctly, so I'm not sure where to go to troubleshoot from here.

Please help.

Still extremely helpful. Thank you for posting. Thanks also to all the comment posters with helpful hints. After following the instructions, it seemed as though it was not yet working until I re-booted. Problem solved.

To all those attempting to use this hint under Snow Leopard: a previous poster was correct, this hint is no longer needed in Snow Leopard. I got tripped up by the lack of that ACL utility as well, and eventually just went to TM prefs and turned it on (I was going to just forget the history). It automatically gave me the option of reusing the old backup—warning that the old computer will no longer be able to use it—creating a new backup, and I'm pretty sure the third option was cancel, of course. HTH, this whole thread helped me.

Indeed, only today I found a post with a screenshot at blog.gerrior.com, after I read about it on Super User. The exact wording, for the search engines:

Would you like to reuse the backup [..] with this computer?

The backup was created on a different computer. If you reuse this backup it can no longer be used by the original computer.

[Do Not Backup Now] [Create New Backup] [Reuse Backup]

I hope Apple will make it a bit more clear that "reuse" implies "keep the history" rather than, for example, "erase the old backup and use all available space for the new Mac".

I hope someone is still reading this...

I recently got a replacement (refurbished) PowerMac G5. I put my old HD in it. But, like replacing the logic board, my Time Machine backup won't continue where it left off.

I've followed the steps above and have gotten the old MAC address. I've verified that the address correct.

After that it all goes down hill.
When I enter the "sudo fsaclctl -p /Volumes/Time Machine -d" command I'm asked for a password. I enter my Mac's password (is that the right password?) and I get
"error (-1) from /Volumes/Time Machine -d. (Unknown error: -1). Support for access control lists is unknown."

Anyway, please be easy on me, I'm a moron with this sort of thing.
Any ideas of what to do next?

(Why can't there be a nice GUI for remedial computer users like me?)

I get the following output, nothing with the old MAC address:

drwxr-xr-x 8 Sachit staff 476 Dec 21 2008 .
drwxrwxrwt@ 6 root admin 204 Jan 12 20:40 ..
-rw-r–r–@ 1 Sachit staff 6148 Jan 12 19:55 .DS_Store
drwx—— 3 root staff 102 Apr 8 2008 .Spotlight-V100
drwxrwxrwt@ 3 Sachit staff 102 Apr 17 2008 .TemporaryItems
d-wx-wx-wt 3 Sachit staff 102 Jan 12 20:40 .Trashes
-rw-r–r– 1 root staff 0 Apr 8 2008 .com.apple.timemachine.supported
drwx—— 2 Sachit staff 4522 Jan 12 20:40 .fseventsd
drwxr-xr-x 3 root staff 102 Apr 8 2008 Backups.backupdb
drwxrwxrwt 3 root admin 238 Jan 12 19:58 lost+found

btw you can also get the old mac address from the sparsebundle image name in the end
old one was 001f5bf1441c and new one is 001ec2c1adde

any help would be greatly appreciated

A tip for other idiots like me who FREAK OUT at doing anything in Terminal:

The second set of Terminal instructions in the post, where it says to enter the following:

$ cd ..
$ ls -al

Remove the $ and the space immediately after it so it's just:

cd ..
ls -al

Same goes for the main instructions that are 4 lines long at the bottom of the post.

Please Help.

System: 10.5.8
backup volume: MBP backup
machine name: X's Computer

I executed the following two commands in Terminal and I could not get my old MAC address.

cm218-253-226-173:MBP backup kwongchu$ cd /Volumes/MBP\ backup/Backups.backupdb
cm218-253-226-173:Backups.backupdb kwongchu$ xattr -p com.apple.backupd.BackupMachineAddress X\'s\ Computer
No such file: X's Computer

Did I type in the command wrong ?
Do I need to install the xattr ?
I forced the Finder to show hidden files and I don't see the file name "X's Computer" in the "MBP backup" root dir or the subdir "Backups.backupdb"

Thank you.

I just ignore confirming the old MAC address and use the new MAC address for renaming the file and executing the sudo xattr -w command, and then all my old back up is back. Thank you for the hint.

However, when I tried to back up now with TM, it seems it tries to backup the whole disk 103G instead of the incremental changes. Any idea ? Thank you.

The original article worked perfectly for me, including only performing an incremental backup.

OS X 10.5, using Time Machine with an external HD connected by USB cable, post logic board replacement

PPC G5 Leopard 10.5.8 to -> Mac Mini Snow Leopard 10.6.4 Time Machine adopt ownership?

Curious to know if this solution would work for my situation...
Time Machine was set up on a PPC G5 running Leopard(10.5.8)
Recently purchased a Mac Mini (Snow Leopard 10.6.4) and had manually transferred desired files from PPC G5 to Mac Mini over LAN. Customized Mini as desired (preferences, apps, etc.) Had removed Time Machine HDD from PPC G5 placed into external enclosure and connected via USB to Mac Mini.

PPC G5 has then since been completely wiped with a fresh install of Leopard.

Is there any way the Mac Mini can take ownership of previous system Time Machine backups and continue with incremental back ups?

Was not aware that Snow Leopard had the Migrate feature with Time Machine - that's why it was not done.

Any help, guidance, direction, magic spells, would be greatly appreciated!

Thank you. Worked fine for me with the following:
- MacBook Pro Core 2 Duo 2.2 GHz (15')
- Mac OS 10.5.8

Time Machine recognized my disk with all previous snapshots and is now (hopefully) doing an incremental backup.

I found that if you name your volumes using spaces in the name, you can avoid having to type the "\ " in between whole words and just drag and drop the volume into the terminal window. Double check to be sure the statement is correct but will save you the headache of typing in all the backslashes and spaces. Enjoy. :)

Hey folks, please forgive for what may seem as something straight forward. I'm having trouble with the second command concerning:

"xattr -p com.apple.backupd.BackupMachineAddress MyMac"

Nothing happens when I input the command. Please, can anyone help me?

-T

I get a hex type address for my time machine backup.
31 30 3A 40 61 3A 64 64 3A 37 30 3B 33 63 3A 62
38 00

how can i get the ascii value??

You can use the command 'xxd' to see the ASCII equivalent of the UUID stored with backup:

xattr -p com.apple.backupd.SnapshotVolumeUUID my_partition | xxd -r -p ; echo

It will return the UUID like this:

ECD4B7A4-5B19-3806-A22A-F2C302567828


You can get the UUID of the real partition in the same format with this command:

diskutil info /Volumes/my_partition | grep UUID | sed "s/[^:]*.[ ]*//"

Thank you very much for this hint!!