free space doesn't update when resizing .dmg

[spookyfish]

Hi, I have been using freeness for a year or so but am still a novice (please be nice and forgive my technical ignorance)...
i am running freeness 9.1.1 (will upgrade as soon as i have finished backing up data) and connecting via AFP.
my issue is: we store lots of large .dmg's and often need to resize them (using disk utility (mac)) lets say we have 800gb available space on the freeness drive, if we have a 200gb .dmg and resize it to 400gb the available space still reads 800gb instead of updating to 600gb. this gets confusing and often leads to the drive becoming 100% full and creates a massive headache.

is there something i can do to make the free space update when i grow a .dmg ??
many thanks

 

[Michael Wulff Nielsen]

No, when you grow a dmg in size nothing happens to it, your mac doesn't pre allocate the space, it just extends the image as it needs it.

This is because by default dmg's are sparse images, you may wish to have a look at hdiutil.

It might be able to do what want.

 

[spookyfish]

thanks Michael, i'm guessing it's something to do with srcdevice ? will look into it some more and see if i can figure it out. thanks again

 

[cyberjock]

This has nothing to do with FreeNAS. As such, moving to offtopic.