I'm trying to replace a 640GB USB2 drive which I use as my Time Machine backup device with a 1TB FireWire 400 drive without losing the current backup history. Given that the 640GB drive is nearly full and the 400Mbps transfer limit of this combination, I realized that this process could take quite some time and might get interrupted in the middle. As a result, I decided to try doing it with
rsync instead of Finder (as Apple suggests). After some false starts and some searching online I settled on the following
rsync -aHXSvPh --hfs-compression --protect-decmpfs /Volumes/Macintosh\ BK/Backups.backupdb /Volumes/Untitled
However, this command is still causing significant bloat on the destination drive (to the point where I don't expect the contents of the old drive to fit on the new one, despite the new drive being about 1.5 times larger). Are there any
rsync options which I'm missing which would eliminate this bloat (I'm using v3.1.2 protocol version 31)?
It has also occurred to me that perhaps I'm using the wrong tool for the job. Would a block copy tool like
dd be more appropriate? If so, how would I set that up so as to make the process resumable in the event of an interruption (such as one caused by a full system crash, something which happened to me twice while running the
rsync command)? I've never used
dd before and so am unfamiliar with its abilities (but do have access to both the version that comes packaged with Mac OSX and the GNU version 8.25).