The backup volume could not be found

Question

Spent a fair amount of time on the phone with Apple last night trying to get my Macbook Air to work with Time Machine/Time Capsule.
Symptoms of my problem included Time Machine Preferences giving the error "The backup volume could not be found"
Console messages complaining about not being able to find the MAC address for machine:
(console is accessed by clicking Go -> Utilities -> Console from the Finder, and then selecting All Messages)
11/7/08 11:06:13 AM System Preferences[123] *Time Machine failed to get MAC address for machine.*
11/7/08 11:13:09 AM /System/Library/CoreServices/backupd[1603] Starting standard backup
11/7/08 11:13:09 AM /System/Library/CoreServices/backupd[1603] Network mountpoint /Volumes/Time Capsule not owned by backupd... remounting
11/7/08 11:13:09 AM kernel AFP_VFS afpfs_mount: /Volumes/Time Capsule-1, pid 1604
11/7/08 11:13:09 AM /System/Library/CoreServices/backupd[1603] Network volume mounted at: /Volumes/Time Capsule-1
11/7/08 11:13:09 AM /System/Library/CoreServices/backupd[1603] *Volume at path /Volumes/Time Capsule-1 does not appear to be the correct backup volume for this computer. (Cookies do not match)*
11/7/08 11:13:09 AM /System/Library/CoreServices/backupd[1603] Backup requested due to disk attach
11/7/08 11:13:14 AM /System/Library/CoreServices/backupd[1603] *Backup failed with error: 18*
And my only network interface was showing up as en1 (instead of en0). You can check this by using Network Utilities:
- On the Finder main menu bar click Go -> Utilities -> Network Utilities
If "Network Interface (en0)" is not an option in the drop down list under "Please select a network interface for information" (mine was showing as en1), then the following steps will probably solve your problem:
1) Enable the root user
- Open the finder
- On the Finder main menu bar click Go -> Utilities -> Directory Utility
- On the menu bar click Edit -> Enable Root User
- set a password (they suggested using the same password as is used for the main user account)
2) Login as the newly enabled root user
- Click Log Out... from the Apple menu on the main menu bar
- select "Other" at the login screen
- enter the user name "root" and the password you set in step 1
3) Drag Preferences folder to the desktop
- open the finder, and click on Macintosh HD and then Library
- drag the Preferences folder onto the desktop
4) Restart the computer
- Click Restart from the Apple menu on the main menu bar
After this, the Network utility should show "Network Interface (en0)", and Time Machine should work.

Answer 1

Jackson,
See this article for the reasons why you see "Time Capsule-1 does not appear to be the right volume..."
[http://discussions.apple.com/thread.jspa?messageID=8116036&#8116036]
As for the error message you are getting, here are several reasons why you would see this message...
*_"Backup Volume Could Not Be Found"_*
First, it is important to distinguish this error message from another, similar Time Machine error that states, “The backup volume could not be mounted”. This is important as the causes and cures for these two errors can be very different.
*Reselect Your Time Machine Disk*
(http://support.apple.com/kb/TS1329)
In the Finder, go up to the "Go" menu and select "Connect to Server".
Click the "Browse" button at the dialogue box.
In the Network window that opens, do you see your TM drive?
Double click it to mount the drive.
Now let's try to reselect it for Time Machine use.
Go to System Preferences --> Time Machine.
Click the "Change Disk..." button.
Select "None" and click "Stop Backing Up".
Now click "Choose Backup Disk" and reselect your drive again.
Close System Preferences and try backing-up again.
On the other hand, does your Time Machine drive NOT appear at all? Is it appearing on your desktop? If it is still connected try disconnecting the cable, waiting a few seconds and then reconnecting the cable. Does the drive mount on the desktop? Try initiating a backup now.
*Disk Fails to Wake From Sleep*
“If your external HD has a sleep function that does not wake for Time Machine backups.  Time Machine will alert you that "The backup volume could not be found", and backups will not be made.” [http://support.apple.com/kb/TS1337]
*3rd-Party Disk Utilities* #
Many external hard disks come with software for maintaining/monitoring hard disk activities. It may have come on a separate CD or been installed on the drive itself. If these programs have been installed they may interfere with Time Machine backups, generate erratic behavior, or cause the drive to ‘disappear’ altogether.
You may never know these applications are there as they may be running in the background. Go to System preferences --> Accounts. Select your account in the pane on the left. Click “Login Items”. Are there any items listed there that might refer to hard disk utilities. If so remove them using the “-” button at the bottom.
*Delete Time Machine Preference .plist*
It may be that the preference list that stores the name of your designated backup disk has become corrupted.
Go to --> Macintosh HD / Library / Preferences (Note: NOT Home / Library / Preferences).
Drag the .plist file labeled,
com.apple.TimeMachine.plist
to the root level of your Macs’ hard drive.
Reboot your computer.
This .plist file is automatically recreated at startup if it is missing.
Now try choosing the external HD in the TM Prefs for backup.
*Time Capsule Has a Long Name*
“When using your Time Capsule for Time Machine backups in Mac OS X 10.5 Leopard or later, the Time Capsule backup volume may not mount and Time Machine may not be able to back up to it. This alert may appear: "Backup volume cannot be found". This can happen if the Time Capsule disk has a long name. [http://support.apple.com/kb/HT1170]
Open AirPort Utility (in /Applications/Utilities).
Click your Time Capsule's icon.
Click "Manual Setup".  
Enter the password for the Time Capsule if prompted.
Click the Disks icon.
Highlight the volume name that appears under "Time Capsule Disk".
In the Name field, enter a name for the volume that is less than 27 characters long.
Click Update.
After Time Capsule restarts, on the Mac(s)using Time Machine, open Time Machine preferences and reselect the Time Capsule volume.”
Let us know if any of these suggestions help.
Cheers!