GetAvailableSize returns the amount of memory used by the partition.

GetDirSize returns the size of directory.

GetMountPoint returns mount point for directory.

GetTotalSize returns total partition size.

GetUserFSQuotaUsage gets file system user usage.

Mount creates mount point and mount source to it.

OverlayMount creates mount point and mount overlay FS to it.

SetUserFSQuota sets file system quota for user.

Umount umount mount point and remove it.