Difference between "size" and "size on disk"
- Thread starter Jcin
- Start date
apj101
VIP Member
size refers to the number of bytes of binary data
size on disk refers to the size in clusters
Lets say a drive has 1GB (1024MB);
now the disk will be divided into multiple clusters of space (the size of the cluster varies depending on the file system used eg fat32, fat 16). Assuming we used the old fat16 file system each cluster will be 16KB.
So a file that is exactly 20KB (20480 bytes) needs to span 2 clusters each of 16KB, so the 20KB file will take 16KB*2 = 32KB on the disk itself.
size on disk refers to the size in clusters
Lets say a drive has 1GB (1024MB);
now the disk will be divided into multiple clusters of space (the size of the cluster varies depending on the file system used eg fat32, fat 16). Assuming we used the old fat16 file system each cluster will be 16KB.
So a file that is exactly 20KB (20480 bytes) needs to span 2 clusters each of 16KB, so the 20KB file will take 16KB*2 = 32KB on the disk itself.