Disk listing, sizing & mounting

Several commands show different views of storage. lsblk shows block devices, df shows mounted filesystem capacity and du measures space used by files and directories.

lsblklsblk -fdf -hdf -hTdu -sh /pathdu -h --max-depth=1 /pathfindmntfindmnt /mount/point

lsblk -f includes filesystem type, label, UUID and mount points. df -h reports capacity in human-readable units and -T adds filesystem type. du -s gives a summary and -h makes sizes readable.

Mounting attaches a filesystem to the Linux directory tree:

sudo mkdir -p /mnt/datasudo mount /dev/sdb1 /mnt/datasudo umount /mnt/datamount | grep /mnt/data

mount without filesystem options usually detects the type automatically. umount detaches it. A filesystem cannot normally be unmounted while a process is actively using it.

Persistent mounts are normally configured in /etc/fstab, preferably using filesystem UUIDs shown by lsblk -f or blkid. A bad fstab entry can affect boot, so test changes with sudo mount -a before restarting.