I have been using a Sparse Bundle image residing in an ext3 (and later ext4) volume as a backup target for TimeMachine. This works OK for the most part, with the added advantage that encrypted backups can reside in a network share (using Samba) using existing non-Apple hardware. When the backup size is over 250GB, though, the file system crashes and then the computer crashes and reboots, corrupting the external hard drive. Does the problem stem from a limitation in the number of files and/or folders that ext3 can create, or is it a driver issue? Sparse Bundles are stored as a series of directories and small files containing bands. At the 250+ GB level this must be very demanding on the file system (FAT32 cannot handle this, the disk starts reporting that it ran our of space), but my understanding was that ext4 should not have limitations in this regard. Can someone confirm whether this is a file system or a driver issue? This is the main reason we bought the drivers and the crashes are very disruptive, not to mention the lack of reliable backups.
