mount

# mount a btrfs partition
sudo mount /dev/nvme0n1p8 -o subvol=@Dropbox /home/linn/Dropbox

# dat file can be mounted as loop device

# add fstab entry for drive that may be unplugged at times to not cause boot failure
#https://man.archlinux.org/man/mount.8#FILESYSTEM-INDEPENDENT_MOUNT_OPTIONS
add the parameter 'nofail' after 'auto' in the options

# change the size of tmp directory
sudo mount -o remount,size=10G /tmp

# mount iso files on linux
mount -o loop /path/to/disk1.iso /mnt/disk

# unmount all subdirectories or unmount a busy disk
umount -l /mnt

# sometime umount doest unmount
sudo umount -R /mnt

# mount all filesystems listed in fstab
mount -a

# unmount all partitions on a device
sudo umount /dev/sdb?*

# mount ntfs partition
mount -t ntfs3  /dev/sdbx