Where did the gigabytes go from the disk?

Question

linux

I have a 500 GB hard drive formatted in ext4. Pre-executed tune2fs -m 0 /dev/sdd1 -> reserved space removed.
df -h
/dev/sdd1 458G 65G 393G
df
/dev/sdd1 479669948 67615520 412038044
cat /proc/partitions
488385559 sdd1

Answer 1

Disk manufacturers indicate the volume in gigabytes (1000 ^ 3 bytes), and information is usually measured in gibibytes (1024 ^ 3 bytes). Hence the difference.
Actually 500 gigabytes = 500 * 1000^3 bytes = 500 * 1000^3 / 1024^3 gibybytes = 465.6 gibibytes.
With a cluster size of 1024 bytes, there should be 500 * 1000^3 / 1024 = 488281250 clusters on the disk.
Which is about 100 mebibytes different from what you have in /proc/partitions

Answer 2

Disk capacity on a disk has always been listed as absolute, not available for use after formatting. But the fact that during formatting a place is reserved for service information - you have to guess for yourself.