Why does 6GB content lead to 30 GB *.img?
Posted: Tue Nov 26, 2013 3:51 pm
I have a bootable USB stick with FAT32 file system. When I right-click on the USB stick drive in WinExplorer then it tells me:
Used space ~ 6.8 GB
Free space: ~25.1 GB
Then I start a backup (either *.img or *.imz) which results in both cases in a file archive size of around 31 GB!
How comes?
I would have expected a size of max 6 GB. Considering a compression of the currently uncompressed files
should even yield a size of 4 GB.
Moreover even if I try to compress the *.img archive AFTERWARDS with the well known famous 7zip compressor
I can shrink it to at most 20GB. Why?
It seems to me that USB image tool collects even those sectors which are empty.
How can I tell USB image tool to only include the really, really filled sectors?
Thank you
Peter
Used space ~ 6.8 GB
Free space: ~25.1 GB
Then I start a backup (either *.img or *.imz) which results in both cases in a file archive size of around 31 GB!
How comes?
I would have expected a size of max 6 GB. Considering a compression of the currently uncompressed files
should even yield a size of 4 GB.
Moreover even if I try to compress the *.img archive AFTERWARDS with the well known famous 7zip compressor
I can shrink it to at most 20GB. Why?
It seems to me that USB image tool collects even those sectors which are empty.
How can I tell USB image tool to only include the really, really filled sectors?
Thank you
Peter