I am trying to move a Time Machine backup from a Firewire disk (called
disk1) directly connected to a computer to a network share, that is, from a folder in/on
/Disk1/Backup.backupdb to a sparsebundle/disk image (called
dmg1) stored in the network share.
Following some suggestions in a Time Machine FAQ I begun a new TM backup to let Time Machine create the needed disk image. As soon as the image was created I cancelled the backup.
Next step was to mount this new image (the resulting volume is called
Time Machine Backup,
TMB for short) and delete the
/TMB/Backups.backupdb directory. Finally I was supposed to copy
/TMB/. Unfortunately, this last step fails with an error message
The volume has the wrong case sensitivity for a backup.
disk1 is not case sensitive (which was/is the default) but for some reason Time Machine sparsebundles are created case sensitive = you can't copy an old local backup (Or can you? Finder prevents it but "logically" it shouldn't be a problem to copy files from a case insensitive volume to a case sensitive volume. The other way around should, however, not work.) to the disk image that is necessary to use if you want to backup to a network volume.
This must be a pretty common usecase, especially since Apple themselves sell a simple NAS (Time Capsule) for this specific purpose, so how is such a migration supposed to be done? The only/most common advice I found when I google for solutions is to start over, but then you waste quite a bit of space as well as lose readily accessible backup history. Not good.