For the last couple of days I’ve been plagued by a Time Machine problem for which seemingly nobody (that Google could find) had a solution:
23.01.14 09:53:44,125 com.apple.backupd: Failed to attach to image: /Volumes/Data/Justus MBP13.sparsebundle, DIHLDiskImageAttach returned: 999
After quite a lot of bug searching I finally found a fix.
The problem started when I moved (rsync’ed) my existing encrypted backup sparsebundle from a QNAP network storage to a new Time Capsule. I removed the old network share from the list of backup targets in the Time Machine system preferences panel and added the Time Capsule as a new target. OS X recognized the existing backup, offered me to continue to use it and asked for its encryption password. After that the Capsule was in the backups list and everything seemed fine. Only didn’t actually making new backups work and every time I tried I was presented with error message. Looking into the Logs I was greeted by the 999 error thats in the quote above.
After trying a lot of other things (resizing the sparsebundle, changing the verification status in the plist, checking permissions, fsck’ing the whole thing over and over) I finally changed its password on the command line with:
hdiutil chpass Justus\ MBP13.sparsebundle
After changing the password I removed the backup target from the Time Machine preferences and added it again. And suddenly it worked.
I can only guess why the new password is better than the old one. Maybe the old one was too long (18 characters) whereas the new one is shorter.