all infos about one’s harddisk:

# tested on:
hostnamectl
   Static hostname: centos.localdomain
  Operating System: CentOS Linux 7 (Core)
       CPE OS Name: cpe:/o:centos:centos:7
            Kernel: Linux 4.15.9
      Architecture: x86-64

# install smart monitoring tools
yum install smartmontools.x86_64

# nice overview over all harddisks
lsblk -o "NAME,MAJ:MIN,RM,SIZE,RO,FSTYPE,MOUNTPOINT,UUID"
# example output:
NAME   MAJ:MIN RM   SIZE RO FSTYPE MOUNTPOINT                   UUID
sdb      8:16   0 465.8G  0                                     
└─sdb1   8:17   0 465.8G  0 ext3                                xxx
sdc      8:32   0 931.5G  0                                     
└─sdc1   8:33   0 931.5G  0 ext3   /run/media/user/SOFTWARE	xxx
sda      8:0    0 238.5G  0                                     
├─sda4   8:4    0     1K  0                                     
├─sda2   8:2    0   100G  0 ext3   /home                        xxx
├─sda5   8:5    0   7.8G  0 swap   [SWAP]                       xxx
├─sda3   8:3    0    50G  0 xfs    /                            xxx
├─sda1   8:1    0     1G  0 xfs    /boot                        xxx
└─sda6   8:6    0  79.7G  0 ext3   /run/media/user/projects	xxx

# disk usage: is it full? if yes how full is it?
# check all disks disk usage
df -h
# specific partition:
df -h /dev/sdc1
Filesystem      Size  Used Avail Use% Mounted on
/dev/sdc1       917G  684G  187G  79% /run/media/user/SOFTWARE

# why is it full? (busybox qnap tested)
# list biggest 30 dir and files
du -a /run/media/user/SOFTWARE | sort -n -r | head -n 30;

# how many blocks does this partition sdc1 have?
# (use sdc to see blocks of the whole harddisk)
blockdev --report /dev/sdc1
RO    RA   SSZ   BSZ   StartSec            Size   Device
rw   256   512  4096       2048   1000203091968   /dev/sdc1

tune2fs -l /dev/sdc1
# example output on external usb attached wd buffalo 1tb
tune2fs 1.42.9 (28-Dec-2013)
Filesystem volume name:   SOFTWARE
Last mounted on:          /run/media/user/SOFTWARE
Filesystem UUID:          xxx
Filesystem magic number:  0xEF53
Filesystem revision #:    1 (dynamic)
Filesystem features:      has_journal ext_attr resize_inode dir_index filetype needs_recovery sparse_super large_file
Filesystem flags:         signed_directory_hash 
Default mount options:    user_xattr acl
Filesystem state:         clean
Errors behavior:          Continue
Filesystem OS type:       Linux
Inode count:              61054976
Block count:              244190208
Reserved block count:     12209510
Free blocks:              61059140
Free inodes:              60765281
First block:              0
Block size:               4096
Fragment size:            4096
Reserved GDT blocks:      965
Blocks per group:         32768
Fragments per group:      32768
Inodes per group:         8192
Inode blocks per group:   512
Filesystem created:       Tue Dec 20 23:58:16 2016
Last mount time:          Wed Jan 15 10:44:57 2020
Last write time:          Wed Jan 15 10:44:57 2020
Mount count:              55
Maximum mount count:      10
Last checked:             Tue Dec  3 17:46:21 2019
Check interval:           2592000 (1 month)
Next check after:         Thu Jan  2 17:46:21 2020
Lifetime writes:          1779 GB
Reserved blocks uid:      0 (user root)
Reserved blocks gid:      0 (group root)
First inode:              11
Inode size:	          256
Required extra isize:     28
Desired extra isize:      28
Journal inode:            8
Default directory hash:   half_md4
Directory Hash Seed:      582a22b3-9507-4d6c-bd9d-68ff9d707ce6
Journal backup:           inode blocks

# same same but different
dumpe2fs -h /dev/sdc1
dumpe2fs 1.42.9 (28-Dec-2013)
Filesystem volume name:   SOFTWARE
Last mounted on:          /run/media/user/SOFTWARE
Filesystem UUID:          xxx
Filesystem magic number:  0xEF53
Filesystem revision #:    1 (dynamic)
Filesystem features:      has_journal ext_attr resize_inode dir_index filetype needs_recovery sparse_super large_file
Filesystem flags:         signed_directory_hash 
Default mount options:    user_xattr acl
Filesystem state:         clean
Errors behavior:          Continue
Filesystem OS type:       Linux
Inode count:              61054976
Block count:              244190208
Reserved block count:     12209510
Free blocks:              61059140
Free inodes:              60765281
First block:              0
Block size:               4096
Fragment size:            4096
Reserved GDT blocks:      965
Blocks per group:         32768
Fragments per group:      32768
Inodes per group:         8192
Inode blocks per group:   512
Filesystem created:       Tue Dec 20 23:58:16 2016
Last mount time:          Wed Jan 15 10:44:57 2020
Last write time:          Wed Jan 15 10:44:57 2020
Mount count:              55
Maximum mount count:      10
Last checked:             Tue Dec  3 17:46:21 2019
Check interval:           2592000 (1 month)
Next check after:         Thu Jan  2 17:46:21 2020
Lifetime writes:          1779 GB
Reserved blocks uid:      0 (user root)
Reserved blocks gid:      0 (group root)
First inode:              11
Inode size:	          256
Required extra isize:     28
Desired extra isize:      28
Journal inode:            8
Default directory hash:   half_md4
Directory Hash Seed:      582a22b3-9507-4d6c-bd9d-68ff9d707ce6
Journal backup:           inode blocks
Journal features:         journal_incompat_revoke
Journal size:             128M
Journal length:           32768
Journal sequence:         0x0001bda3
Journal start:            1

# run filesystem check on this partition
# write harddisk cache to disk
sync;
# unmount all partitions of sdc
umount /dev/sdc*;
fsck -v -y -f /dev/sdc1

# get hardware informations about sata attached disks
# (usually does not work for usb harddisks)
hdparm -i /dev/sda

/dev/sda:

Model=SanDisk SDSSDHP256G, FwRev=X2316RL, SerialNo=XXXXX
Config={ Fixed }
RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=0
BuffType=unknown, BuffSize=unknown, MaxMultSect=1, MultSect=1
CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=500118192
IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
PIO modes: pio0 pio1 pio2 pio3 pio4
DMA modes: mdma0 mdma1 mdma2
UDMA modes: udma0 udma1 udma2 udma3 udma4 udma5 *udma6
AdvancedPM=yes: unknown setting WriteCache=enabled
Drive conforms to: unknown: ATA/ATAPI-4,5,6,7

* signifies the current active mode

# smartctl still manages to get hardware details about the usb attached harddisk
smartctl -i /dev/sdc
smartctl 6.5 2016-05-07 r4318 [x86_64-linux-4.15.9] (local build)
Copyright (C) 2002-16, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family:     Western Digital Caviar Green
Device Model:     WDC WD10EACS-00ZJB0
Serial Number:    WD-xxx
LU WWN Device Id: 5 0014ee 201410d3d
Firmware Version: 01.01B01
User Capacity:    1,000,204,886,016 bytes [1.00 TB]
Sector Size:      512 bytes logical/physical
Device is:        In smartctl database [for details use: -P show]
ATA Version is:   ATA8-ACS (minor revision not indicated)
SATA Version is:  SATA 2.5, 3.0 Gb/s
Local Time is:    Wed Jan 15 16:57:24 2020 CET
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

# read "S.M.A.R.T. (Self-Monitoring, Analysis and Reporting Technology" telemetry from drive
smartctl -H /dev/sdc
smartctl 6.5 2016-05-07 r4318 [x86_64-linux-4.15.9] (local build)
Copyright (C) 2002-16, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED
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