<sup>*Note: this answer is based on the sources listed at the bottom, not experimental data. I will update with experimental data if/when I find the opportunity to perform the relevant tests. I offer no guarantees on the correctness of this information.*</sup>
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## Filesystem theory
First, a little bit of filesytem theory. There are two 'sizes' that might be relevant to a volume:
* The filesystem (FAT32, exFAT, NTFS, etc.) size. This is defined as part of the filesystem itself, somewhere in its metadata.