There are metadata (that are used to manage the file system in the partition), and the file system will need more metadata in a larger partition.
You get a hint of what kinds of metadata there are, when you read the manual
describing options for an
ext4 file system, but other file systems have similar metadata, at least some of the metadata.
The following paragraphs describe some aspect of the metadata. Usually you need not worry about these options, you can use the standard settings of the file system, and it will work. As described in the manual, the size of the metadata will vary with the size of the partition and file system.
packed_meta_blocks[= <0 to disable, 1 to enable>]
Place the allocation bitmaps and the inode table at the beginning
of the disk. This option requires that the flex_bg file system
feature to be enabled in order for it to have effect, and will
also create the journal at the beginning of the file system. This
option is useful for flash devices that use SLC flash at the
beginning of the disk. It also maximizes the range of contiguous
data blocks, which can be useful for certain specialized use
cases, such as supported Shingled Drives.
Specify the bytes/inode ratio. mke2fs creates an inode for
every bytes-per-inode bytes of space on the disk. The larger
the bytes-per-inode ratio, the fewer inodes will be created.
This value generally shouldn't be smaller than the blocksize of
the filesystem, since in that case more inodes would be made
than can ever be used. Be warned that it is not possible to
change this ratio on a filesystem after it is created, so be
careful deciding the correct value for this parameter. Note
that resizing a filesystem changes the numer of inodes to main‐
tain this ratio.
Overrides the default calculation of the number of inodes that
should be reserved for the filesystem (which is based on the
number of blocks and the bytes-per-inode ratio). This allows
the user to specify the number of desired inodes directly.
-j Create the filesystem with an ext3 journal. If the -J option is
not specified, the default journal parameters will be used to
create an appropriately sized journal (given the size of the
filesystem) stored within the filesystem. Note that you must be
using a kernel which has ext3 support in order to actually make
use of the journal.
Not metadata, but depending on the size of the file system
Specify the percentage of the filesystem blocks reserved for the
super-user. This avoids fragmentation, and allows root-owned
daemons, such as syslogd(8), to continue to function correctly
after non-privileged processes are prevented from writing to the
filesystem. The default percentage is 5%.