Smart Update disk image?

[DavidCB]

I have a sparse bundle disk image in both volume A and volume B, along with other files. If I make changes to the disk image in A, when I use Smart Update to copy A to B, is the entire disk image copied again or only the changes?

Also, does the same apply to all types of disk images (not just sparse bundle ones), and does encryption make any difference?

Thank you,

David

[dnanian]

If you're copying them mounted (that is, from volume to volume), they're treated just like any other drive, and the changes are made. Same for all volumes, image or not, encryption or not.

[DavidCB]

What if the disk image is just one of many files on a drive and you are Smart Updating the whole drive? (In this case the disk image would not be mounted.)

David

[dnanian]

Then the bands of the bundle that have changed would be copied. In the case of a sparse image, the whole thing (if changed).

[Gardenian]

Then the bands of the bundle that have changed would be copied. In the case of a sparse image, the whole thing (if changed).
In the case, then, where one wants to keep synced two external drives which contain sparse images, the most efficient procedure without a custom script would seem to be, first, to mount the sparse images on both drives, then perform a copy between them; finally, perform a copy between the drives, which will skip the sparse images and copy the other modified files on the source drive. But there is probably something wrong with this procedure, yes?

[dnanian]

Yes. The dates of the band files will be different, regardless of the state of their contents, and so will be copied again.