df
Disk Free is a common utility that displays used anmd available space on mounted filesystems.
du
Disk usage tells us which files and dirs are taking up space. It can be used to see who or what is using most space
fio
Flexible I/O Tester is sued to simulate different read/writes to benchmark performance.
mkfs
Make filesystem, used to create filesystem types on a partition or drive.
fschk / fsck
fschck checks, repairs, and updates Linux inodes and metadata.
xfs_repair
This is like fschk / fsck, but for XFS.
resize2fs
This is used to grow or shrink ext-based filesystems.
xfs_growfs
Like resize2fs but for XFS; note that it only supports growing, and not shrinking.