Hi Peter, Just a quick reply before I shutdown from computer work for the day.
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. *Unmount the Backup Disk Image* (TC) If, for some reason, you have manually mounted the Time Machine backup disk image (sparsebundle), or Time Machine failed to eject it after the previous backup, subsequent backups may fail. (Console - “Failed to mount disk image”… “Backup failed with error: 21”) Eject the backup disk image (sparsebundle) by either clicking the little Eject icon to the right of the disk image in the Finders’ Sidebar, or Ctrl-Click the drive icon on the desktop and select “Eject” from the contextual menu. Now try backing up again or launching Time Machine to view previous backups. *Proper Computer Name* # Make sure your computer has a proper name. Go to System Preferences > Sharing. Time Machine needs to differentiate your computer from others on your network (i.e. "Bills MacBook" or "Office iMac"). If the "Computer Name" field is blank, create a name. Realise that if this step is necessary, you will likely have to start the Time Machine backup process over again and do another full initial backup. Time Machine may experience problems if your computer name includes certain characters. Make sure the computer name only includes ASCII characters from the following set. (0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ) Once a change in the computer name occurs, you should stop and restart Sharing on the affected computer. Uncheck and then recheck Sharing in the Services list on the left. Cheers, Ronni Sent from Ronni's iPad On 02/08/2012, at 9:08 PM, Peter Crisp <[email protected]> wrote: > Hi, I have 3 Macbooks in my house all attached to a Time Capsule for backing > up. One (MB1) has been backing up VERY reliably since 2009 when it was first > attached, the other two (MB2 and MB3) I thought were backing up reliably > since their connection in early 2012 but on closer inspection, it is not the > case. > > MB1 is an SL (10.6.8) White Macbook, the other two are both 10.5.8 (Leopard) > Black Macbooks. > > Connection was easy when MB2 and MB3 were attached and I thought they were > backing up reliably ever since they were connected and I was confident as MB1 > was so reliable. > > Just the other day I noticed MB2 was not backing up so I took interest to > watch it go through the process. It starts by "preparing backup" then > responds with "The backup disc image could not be mounted". In Finder on MB2 > I am able to see "....Time Capsule" in the devices panel, but when selected, > the sparesebundle does not appear as they do when doing this on the other two > MB's. The "Modified" date on the MB2 Sparesebundle when checked from the > other MB's is in fact the same date it was fist set up - so it's done nothing > the whole time since January 2012. > > How do I reset it to effectively start from scratch - as no backups have > occurred in any case, there is no backup to loose. I done some navigating > around to try it all over but still no effect. > > Regards > > Pete. > -- The WA Macintosh User Group Mailing List -- Archives - <http://www.wamug.org.au/mailinglist/archives.shtml> Guidelines - <http://www.wamug.org.au/mailinglist/guidelines.shtml> Settings & Unsubscribe - <http://lists.wamug.org.au/listinfo/wamug.org.au-wamug>
