Get tar's uncompressed size

Seeker

Seeker

Using cmd to list compressed tar archive shows it's uncompressed size is: 473 MB
However, when I do uncompress it, on UFS (HDD) it's size is 535 MB

I've tried to calculate tar's size by method where, if size of file is less then sector size (512), then round it to 512 bytes.
This lifted 473 MB to 477 MB.
Duh! Not even close to 535 MB.

So?
What should I do?
 
Files are stored on disk using complete sectors, thus all on-disk file sizes will be multiples of 512 B. However, UFS smallest addressable block is (I believe) something like 2K. So files that are 3 KB in size will use 4 KB of disk space. Any files that aren't perfect multiples of the block size will "waste" the space at the end of the block, thus inflating the on-disk sizes.

Or, something along those lines.

This was most noticeable with FAT32 where the allocation size on large partitions was 32KB, so a tiny 1 KB file would "waste" 31 KB of disk.
 
Well, for UFS, it defaults to: block size of 16384 bytes (16 KB), a fragment size of 2048 bytes (2 KB)
When a file greater than 16 KB is created, ie: 19K file, it will occupy 1 block and 2 fragments from the next block(1 block holds 8 fragments).
Now I went for a fragment size of 2048 bytes, this calculated size to 499 MB.
Still not close to 535 MB.
 
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