lsblk df

df(1) - Linux manual page http://man7.org/linux/man-pages/man1/df.1.html

 report file system disk space usage

       This manual page documents the GNU version of df.  df displays the
       amount of disk space available on the file system containing each
       file name argument.  If no file name is given, the space available on
       all currently mounted file systems is shown.  Disk space is shown in
       1K blocks by default, unless the environment variable POSIXLY_CORRECT
       is set, in which case 512-byte blocks are used.
 
       If an argument is the absolute file name of a disk device node
       containing a mounted file system, df shows the space available on
       that file system rather than on the file system containing the device
       node.  This version of df cannot show the space available on
       unmounted file systems, because on most kinds of systems doing so
       requires very nonportable intimate knowledge of file system
       structures.
 

lsblk(8) - Linux manual page http://man7.org/linux/man-pages/man8/lsblk.8.html

list block devices

       lsblk lists information about all available or the specified block
       devices.  The lsblk command reads the sysfs filesystem and udev db to
       gather information. If the udev db is not available or lsblk is
       compiled without udev support than it tries to read LABELs, UUIDs and
       filesystem types from the block device. In this case root permissions
       are necessary.
 
       The command prints all block devices (except RAM disks) in a tree-
       like format by default.  Use lsblk --help to get a list of all
       available columns.
 
       The default output, as well as the default output from options like
       --fs and --topology, is subject to change.  So whenever possible, you
       should avoid using default outputs in your scripts.  Always
       explicitly define expected columns by using --output columns-list in
       environments where a stable output is required.
 
       Note that lsblk might be executed in time when udev does not have all
       information about recently added or modified devices yet. In this
       case it is recommended to use udevadm settle before lsblk to
       synchronize with udev.
 

[root@hadoop2 ~]# lsblk
NAME                        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda                           8:0    0 931.5G  0 disk
├─sda1                        8:1    0   200M  0 part
├─sda2                        8:2    0   500M  0 part /boot
└─sda3                        8:3    0 930.8G  0 part
  ├─VolGroup-lv_root (dm-0) 253:0    0    50G  0 lvm  /
  ├─VolGroup-lv_swap (dm-1) 253:1    0   7.7G  0 lvm  [SWAP]
  └─VolGroup-lv_home (dm-2) 253:2    0 873.1G  0 lvm  /home
[root@hadoop2 ~]# lsblk --help
 
Usage:
 lsblk [options] [<device> ...]
 
Options:
 -a, --all            print all devices
 -b, --bytes          print SIZE in bytes rather than in human readable format
 -d, --nodeps         don't print slaves or holders
 -D, --discard        print discard capabilities
 -e, --exclude <list> exclude devices by major number (default: RAM disks)
 -I, --include <list> show only devices with specified major numbers
 -f, --fs             output info about filesystems
 -h, --help           usage information (this)
 -i, --ascii          use ascii characters only
 -m, --perms          output info about permissions
 -l, --list           use list format ouput
 -n, --noheadings     don't print headings
 -o, --output <list>  output columns
 -P, --pairs          use key="value" output format
 -r, --raw            use raw output format
 -s, --inverse        inverse dependencies
 -t, --topology       output info about topology
 -V, --version        output version information and exit
 
Available columns (for --output):
        NAME  device name
       KNAME  internal kernel device name
     MAJ:MIN  major:minor device number
      FSTYPE  filesystem type
  MOUNTPOINT  where the device is mounted
       LABEL  filesystem LABEL
        UUID  filesystem UUID
          RA  read-ahead of the device
          RO  read-only device
          RM  removable device
       MODEL  device identifier
        SIZE  size of the device
       STATE  state of the device
       OWNER  user name
       GROUP  group name
        MODE  device node permissions
   ALIGNMENT  alignment offset
      MIN-IO  minimum I/O size
      OPT-IO  optimal I/O size
     PHY-SEC  physical sector size
     LOG-SEC  logical sector size
        ROTA  rotational device
       SCHED  I/O scheduler name
     RQ-SIZE  request queue size
        TYPE  device type
    DISC-ALN  discard alignment offset
   DISC-GRAN  discard granularity
    DISC-MAX  discard max bytes
   DISC-ZERO  discard zeroes data
 
For more details see lsblk(8).
[root@hadoop2 ~]# df
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/mapper/VolGroup-lv_root
                      51475068  46818364   2035264  96% /
tmpfs                  3975284         0   3975284   0% /dev/shm
/dev/sda2               487652     80945    381107  18% /boot
/dev/mapper/VolGroup-lv_home
                     901020952 110191196 745053884  13% /home
[root@hadoop2 ~]# df  --help
Usage: df [OPTION]... [FILE]...
Show information about the file system on which each FILE resides,
or all file systems by default.
 
Mandatory arguments to long options are mandatory for short options too.
  -a, --all             include dummy file systems
  -B, --block-size=SIZE  use SIZE-byte blocks
      --direct          show statistics for a file instead of mount point
      --total           produce a grand total
  -h, --human-readable  print sizes in human readable format (e.g., 1K 234M 2G)
  -H, --si              likewise, but use powers of 1000 not 1024
  -i, --inodes          list inode information instead of block usage
  -k                    like --block-size=1K
  -l, --local           limit listing to local file systems
      --no-sync         do not invoke sync before getting usage info (default)
  -P, --portability     use the POSIX output format
      --sync            invoke sync before getting usage info
  -t, --type=TYPE       limit listing to file systems of type TYPE
  -T, --print-type      print file system type
  -x, --exclude-type=TYPE   limit listing to file systems not of type TYPE
  -v                    (ignored)
      --help     display this help and exit
      --version  output version information and exit
 
Display values are in units of the first available SIZE from --block-size,
and the DF_BLOCK_SIZE, BLOCK_SIZE and BLOCKSIZE environment variables.
Otherwise, units default to 1024 bytes (or 512 if POSIXLY_CORRECT is set).
 
SIZE may be (or may be an integer optionally followed by) one of following:
KB 1000, K 1024, MB 1000*1000, M 1024*1024, and so on for G, T, P, E, Z, Y.
 
Report df bugs to bug-coreutils@gnu.org
GNU coreutils home page: <http://www.gnu.org/software/coreutils/>
General help using GNU software: <http://www.gnu.org/gethelp/>
For complete documentation, run: info coreutils 'df invocation'
[root@hadoop2 ~]#