Can see the serial or model number of your hard disks from the terminal, the below commands are get information lshw, lsblk, hdparm, smartctl, palimpsest.

lshw (Hardware Lister)

#  lshw -class disk

  *-disk                  
       description: ATA Disk
       product: ST500LM012 HN-M5
       vendor: Seagate
       physical id: 0.0.0
       bus info: scsi@0:0.0.0
       logical name: /dev/sda
       version: 2AR1
       serial: S2RSJ9DCA02798
       size: 465GiB (500GB)
       capabilities: partitioned partitioned:dos
       configuration: ansiversion=5 sectorsize=4096 signature=00079661
  *-cdrom
       description: DVD-RAM writer
       product: DVD-RAM UJ8D1
       vendor: MATSHITA
       physical id: 0.1.0
       bus info: scsi@0:0.1.0
       logical name: /dev/cdrom
       logical name: /dev/sr0
       version: L.01
       capabilities: removable audio cd-r cd-rw dvd dvd-r dvd-ram
       configuration: ansiversion=5 status=nodisc

Find out disk name only:
 
#  lshw -short -C disk

H/W path        Device      Class          Description
======================================================
/0/1/0.0.0      /dev/sda    disk           500GB ST500LM012 HN-M5
/0/1/0.1.0      /dev/cdrom  disk           DVD-RAM UJ8D1


If you could not found the command try to install using yum or apt-get
 
# lshw -class disk

-bash: lshw: command not found
If you dont have the lshw command just install using yum command
# apt-get install lshw*

# yum install lshw*

...
Dependencies Resolved
===========================================
 Package                 Arch       Version          Repository        Size
============================================
 lshw                    i386       2.15-1.el5.rf    rpmforge          1.4 M
 lshw-gui                i386       2.15-1.el5.rf    rpmforge          417 k
===============================================
Total download size: 1.8 M
Is this ok [y/N]: y
...
Installed: lshw.i386 0:2.15-1.el5.rf lshw-gui.i386 0:2.15-1.el5.rf
Complete!

lsblk

lsblk is used to get infroamtion about all block devices and it not shows infromation about RAM.
 
#  yum install util-linux-ng

# apt-get install util-linux-ng

List out block device like model,kname,size and type,
 
# lsblk -io MODEL,KNAME,SIZE,TYPE

MODEL            KNAME   SIZE TYPE
ST500LM012 HN-M5 sda   465.8G disk
                 sda1    464G part
                 sda2      1K part
                 sda5    1.8G part
DVD-RAM UJ8D1    sr0    1024M rom

or
# cat /proc/partitions

major minor  #blocks  name

   8        0  488386584 sda
   8        1  486511616 sda1
   8        2          1 sda2
   8        5    1871872 sda5
  11        0    1048575 sr0

hdparm

Hdparm is used to check the hard drive read and writing speed.

Redhat/CentOS
 
# yum install hdparm -y

Ubuntu/Debian
 
# apt-get install hdparm -y

Show harddisk details like Model/Serial number, configuration, Capabilities, features.
 
#  hdparm -I /dev/sda

/dev/sda:

ATA device, with non-removable media
    Model Number:       ST500LM012 HN-M500MBB                   
    Serial Number:      S2RSJ9DCA02798      
    Firmware Revision:  2AR10002
    Transport:          Serial, ATA8-AST, SATA 1.0a, SATA II Extensions, SATA Rev 2.5, SATA Rev 2.6, SATA Rev 3.0
Standards:
    Used: unknown (minor revision code 0x0028)
    Supported: 8 7 6 5
    Likely used: 8
Configuration:
    Logical        max    current
    cylinders    16383    16383
    heads        16    1
    sectors/track    63    63
    --
    CHS current addressable sectors:    1032129
    LBA    user addressable sectors:  268435455
    LBA48  user addressable sectors:  976773168
    Logical  Sector size:                   512 bytes
    Physical Sector size:                  4096 bytes
    Logical Sector-0 offset:                  0 bytes
    device size with M = 1024*1024:      476940 MBytes
    device size with M = 1000*1000:      500107 MBytes (500 GB)
    cache/buffer size  = 8192 KBytes
    Form Factor: 2.5 inch
    Nominal Media Rotation Rate: 5400
Capabilities:
    LBA, IORDY(can be disabled)
    Queue depth: 32
    Standby timer values: spec'd by Standard, no device specific minimum
    R/W multiple sector transfer: Max = 16    Current = 16
    Advanced power management level: 128
    Recommended acoustic management value: 254, current value: 128
    DMA: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 udma5 *udma6
         Cycle time: min=120ns recommended=120ns
    PIO: pio0 pio1 pio2 pio3 pio4
         Cycle time: no flow control=120ns  IORDY flow control=120ns
Commands/features:
    Enabled    Supported:
       *    SMART feature set
            Security Mode feature set
       *    Power Management feature set
       *    Write cache
       *    Look-ahead
       *    Host Protected Area feature set
       *    WRITE_BUFFER command
       *    READ_BUFFER command
       *    NOP cmd
       *    DOWNLOAD_MICROCODE
       *    Advanced Power Management feature set
            Power-Up In Standby feature set
       *    SET_FEATURES required to spinup after power up
            SET_MAX security extension
       *    Automatic Acoustic Management feature set
       *    48-bit Address feature set
       *    Device Configuration Overlay feature set
       *    Mandatory FLUSH_CACHE
       *    FLUSH_CACHE_EXT
       *    SMART error logging
       *    SMART self-test
       *    General Purpose Logging feature set
       *    64-bit World wide name
       *    IDLE_IMMEDIATE with UNLOAD
       *    WRITE_UNCORRECTABLE_EXT command
       *    {READ,WRITE}_DMA_EXT_GPL commands
       *    Segmented DOWNLOAD_MICROCODE
       *    Gen1 signaling speed (1.5Gb/s)
       *    Gen2 signaling speed (3.0Gb/s)
       *    Native Command Queueing (NCQ)
       *    Host-initiated interface power management
       *    Phy event counters
       *    Idle-Unload when NCQ is active
       *    NCQ priority information
            DMA Setup Auto-Activate optimization
            Device-initiated interface power management
       *    Software settings preservation
       *    SMART Command Transport (SCT) feature set
       *    SCT Read/Write Long (AC1), obsolete
       *    SCT Write Same (AC2)
       *    SCT Error Recovery Control (AC3)
       *    SCT Features Control (AC4)
       *    SCT Data Tables (AC5)
Security:
    Master password revision code = 65534
        supported
    not    enabled
    not    locked
        frozen
    not    expired: security count
        supported: enhanced erase
    104min for SECURITY ERASE UNIT. 104min for ENHANCED SECURITY ERASE UNIT.
Logical Unit WWN Device Identifier: 50004cf2088fd241
    NAA        : 5
    IEEE OUI    : 0004cf
    Unique ID    : 2088fd241
Checksum: correct

smartctl

Install  smartctl command,
 
# apt-get install smartmontools

# smartctl -d ata -a -i /dev/sda

Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages were automatically installed and are no longer required:
  lib32z1 libc6-i386
Use 'apt-get autoremove' to remove them.
The following extra packages will be installed:
  heirloom-mailx
Suggested packages:
  exim4 mail-transport-agent gsmartcontrol smart-notifier
Recommended packages:
  mailx mailutils
The following NEW packages will be installed:
  heirloom-mailx smartmontools
0 upgraded, 2 newly installed, 0 to remove and 53 not upgraded.
Need to get 693 kB of archives.
After this operation, 2,168 kB of additional disk space will be used.
Do you want to continue? [Y/n] Y
Get:1 http://archive.ubuntu.com/ubuntu/ trusty/universe heirloom-mailx amd64 12.5-2 [247 kB]
Get:2 http://archive.ubuntu.com/ubuntu/ trusty/main smartmontools amd64 6.2+svn3841-1.2 [445 kB]
Fetched 693 kB in 6s (103 kB/s)                                                
Selecting previously unselected package heirloom-mailx.
(Reading database ... 184903 files and directories currently installed.)
Preparing to unpack .../heirloom-mailx_12.5-2_amd64.deb ...
Unpacking heirloom-mailx (12.5-2) ...
Selecting previously unselected package smartmontools.
Preparing to unpack .../smartmontools_6.2+svn3841-1.2_amd64.deb ...
Unpacking smartmontools (6.2+svn3841-1.2) ...
Processing triggers for man-db (2.6.7.1-1ubuntu1) ...
Processing triggers for ureadahead (0.100.0-16) ...
ureadahead will be reprofiled on next reboot
Setting up heirloom-mailx (12.5-2) ...
update-alternatives: using /usr/bin/heirloom-mailx to provide /usr/bin/mailx (mailx) in auto mode
Setting up smartmontools (6.2+svn3841-1.2) ...
Processing triggers for ureadahead (0.100.0-16) ...
root@laks:/dev/disk# smartctl -d ata -a -i /dev/sda
smartctl 6.2 2013-07-26 r3841 [x86_64-linux-3.13.0-37-generic] (local build)
Copyright (C) 2002-13, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family:     Seagate Momentus SpinPoint M8 (AF)
Device Model:     ST500LM012 HN-M500MBB
Serial Number:    S2RSJ9DCA02798
LU WWN Device Id: 5 0004cf 2088fd241
Firmware Version: 2AR10002
User Capacity:    500,107,862,016 bytes [500 GB]
Sector Sizes:     512 bytes logical, 4096 bytes physical
Rotation Rate:    5400 rpm
Device is:        In smartctl database [for details use: -P show]
ATA Version is:   ATA8-ACS T13/1699-D revision 6
SATA Version is:  SATA 3.0, 3.0 Gb/s (current: 3.0 Gb/s)
Local Time is:    Mon Nov 10 16:53:18 2014 IST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

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

General SMART Values:
Offline data collection status:  (0x00)    Offline data collection activity
                    was never started.
                    Auto Offline Data Collection: Disabled.
Self-test execution status:      (   0)    The previous self-test routine completed
                    without error or no self-test has ever
                    been run.
Total time to complete Offline
data collection:         ( 6480) seconds.
Offline data collection
capabilities:              (0x5b) SMART execute Offline immediate.
                    Auto Offline data collection on/off support.
                    Suspend Offline collection upon new
                    command.
                    Offline surface scan supported.
                    Self-test supported.
                    No Conveyance Self-test supported.
                    Selective Self-test supported.
SMART capabilities:            (0x0003)    Saves SMART data before entering
                    power-saving mode.
                    Supports SMART auto save timer.
Error logging capability:        (0x01)    Error logging supported.
                    General Purpose Logging supported.
Short self-test routine
recommended polling time:      (   2) minutes.
Extended self-test routine
recommended polling time:      ( 108) minutes.
SCT capabilities:            (0x003f)    SCT Status supported.
                    SCT Error Recovery Control supported.
                    SCT Feature Control supported.
                    SCT Data Table supported.

SMART Attributes Data Structure revision number: 16
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
  1 Raw_Read_Error_Rate     0x002f   100   100   051    Pre-fail  Always       -       4
  2 Throughput_Performance  0x0026   252   252   000    Old_age   Always       -       0
  3 Spin_Up_Time            0x0023   091   091   025    Pre-fail  Always       -       2857
  4 Start_Stop_Count        0x0032   097   097   000    Old_age   Always       -       3125
  5 Reallocated_Sector_Ct   0x0033   252   252   010    Pre-fail  Always       -       0
  7 Seek_Error_Rate         0x002e   252   252   051    Old_age   Always       -       0
  8 Seek_Time_Performance   0x0024   252   252   015    Old_age   Offline      -       0
  9 Power_On_Hours          0x0032   100   100   000    Old_age   Always       -       4093
 10 Spin_Retry_Count        0x0032   252   252   051    Old_age   Always       -       0
 11 Calibration_Retry_Count 0x0032   100   100   000    Old_age   Always       -       10
 12 Power_Cycle_Count       0x0032   100   100   000    Old_age   Always       -       885
191 G-Sense_Error_Rate      0x0022   100   100   000    Old_age   Always       -       210
192 Power-Off_Retract_Count 0x0022   252   252   000    Old_age   Always       -       0
194 Temperature_Celsius     0x0002   051   042   000    Old_age   Always       -       49 (Min/Max 22/58)
195 Hardware_ECC_Recovered  0x003a   100   100   000    Old_age   Always       -       0
196 Reallocated_Event_Count 0x0032   252   252   000    Old_age   Always       -       0
197 Current_Pending_Sector  0x0032   252   252   000    Old_age   Always       -       0
198 Offline_Uncorrectable   0x0030   252   252   000    Old_age   Offline      -       0
199 UDMA_CRC_Error_Count    0x0036   200   200   000    Old_age   Always       -       0
200 Multi_Zone_Error_Rate   0x002a   100   100   000    Old_age   Always       -       2339
223 Load_Retry_Count        0x0032   100   100   000    Old_age   Always       -       10
225 Load_Cycle_Count        0x0032   099   099   000    Old_age   Always       -       10777

SMART Error Log Version: 1
No Errors Logged

SMART Self-test log structure revision number 1
No self-tests have been logged.  [To run self-tests, use: smartctl -t]

SMART Selective self-test log data structure revision number 0
Note: revision number not 1 implies that no selective self-test has ever been run
 SPAN  MIN_LBA  MAX_LBA  CURRENT_TEST_STATUS
    1        0        0  Completed [00% left] (0-65535)
    2        0        0  Not_testing
    3        0        0  Not_testing
    4        0        0  Not_testing
    5        0        0  Not_testing
Selective self-test flags (0x0):
  After scanning selected spans, do NOT read-scan remainder of disk.
If Selective self-test is pending on power-up, resume after 0 minute delay.

palimpsest:

Also, graphically view disk utility by palimpsest command,
 
#  apt-get install gnome-disk-utility

Run it from a terminal
 
# palimpsest