S.M.A.R.T stands for self-monitoring, analysis and reporting technology.  It is a monitoring system integreated in storage hardware with the purpose of tracking  and reporting the values of several characteristics of that device. These values, often refered to as SMART attributes, might be indicators, in some cases, of impending hardware failures. 

SMART attributes are a series of raw values reported by drives during operation. These attributes can be used to interpret the health of the drives and in some cases even predict an imminent hardware failure. Currently, there's no standard for which attributes a drive manufacturer should report, in what format and how each attribute must be interpreted. 

The following list contains some S.M.A.R.T. attributes and the typical meaning of their raw values:

Sources:

• https://en.wikipedia.org/wiki/S.M.A.R.T.
• https://www.backblaze.com/blog-smart-stats-2014-8.html
• https://www.hdsentinel.com/help/en/56_attrib.html 

A solid state drive (SSD) is a type of storage that uses  integrated circuit assemblies as memory to store data persistenly. In contrast with traditional hard disk drives (HDDs), SSDs don't have any moving mechanical components. This makes SSDs a better choice for portable devices since they are more resistant to physical shock, run silently, have quicker access time and lower latency.

Note: SSDs have a limit on the amount of data that can be read and written on the drive. 

Sources:

• https://www.windowscentral.com/guide-solid-state-drives
• https://en.wikipedia.org/wiki/Solid-state_drive 
• https://www.digitaltrends.com/computing/what-is-an-ssd/ 

A hard disk drive (HDD) is a type of storage that uses magnetic disks to store data persistently. It's the most common form of data storage used in personal computers as well as enterprises. In contrast with SSDs, HDDs don't have a limit on the amount of data that can be read or written on the device. 

Note: Since HDDs contain mechanical components, they are more prone to damages caused by physical shock, which can lead to data loss or hardware failure. 

Sources:

• https://www.techopedia.com/definition/5288/hard-disk-drive
• https://en.wikipedia.org/wiki/Hard_disk_drive 

HDDs and SSDs have major differences in terms of:

Technology: HDDs use magnetic disks to store data persistently whereas SSDs use  integrated circuit assemblies. In contrast with HDDs, SSDs have a limit on the amount of data that can be read and written on the drive.

Price and Capacity: Currently SSDs are much more expensive than HDDs. For this reason, high capacities are most commonly found on HDDs, since they are much more affordable than SSDs. 

Speed: SSDs are a lot faster than HDDs.

Durability: Although there isn't any clear evidence on which type of drive experiences the most hardware failures, SSDs are much more resistant to shock and sudden drops than HHDs, since they don't contain any mechanical parts.

 Sources:

• https://www.windowscentral.com/guide-solid-state-drives
• https://en.wikipedia.org/wiki/Solid-state_drive 
• https://www.pcmag.com/article2/0,2817,2404258,00.asp
• https://en.wikipedia.org/wiki/Hard_disk_drive 

Backblaze, which is a cloud storage company, shared health statistics for about 60.000 hard drives with more than one billion hours in service. Their storage center contains hard drives from these manufacturers:

• HGST
• Seagate
• Toshiba
• Western Digital

After analyzing the failure rates of all the disks for each manufacturer during 2014, 2015 and 2016, they came up with the following graph:

Looking at the results, it's clear that HGST has the least amount of failure rates, therefore has the most realiable hard disk drives. 

Note: The above results should be taken with a grain of sault since the data presented is about specific disk models and cannot be used as a general indicator for the reliability of the disks produced by a manufacturer.

Source: https://www.backblaze.com/b2/hard-drive-test-data.html 

Although there's not a definite answer to how long a disk drive lasts, you can expect your hard drive to survive for at least 3 to 5 years.  In a study contacted by Backblaze with more than 25000 disk drives, it was observed that about 80% of the drives were still operating after 4 years.  After 3 years though, they have noticed that the failure rate of the disk drives increased significally. 

Note: The drives tested reside in a controled environment and thus don't face several challenges other disks face (e.g. disks on a laptop), which could contribute in a reduced lifespan.

Source: https://www.backblaze.com/how-long-do-disk-drives-last.html

In the context of storage devices, Power On Hours  refers to the lenght of time, in terms of hours, the drive has been operational.  It is used as an indicator of the age of the drive. A storage device with a high value of POH typically has a higher failure probability than a storage device with a low value of POH.  

Annualized failure rate is the projected failure rate for a year. It is the relation between the amount of failed drives of a particular model and their hours in operation per year.  More precisely: 

AFR = (100 * amount of failed drives) / (total power on hours /24/365)

Sources:

• https://www.backblaze.com/blog/hard-drive-reliability-q4-2015/ 

In general, drive manufacturers suggest keeping the drives in a cooler environment to prolong their lifespan.

Despite the above suggestion, there’s no clear evidence that temperature affects in any way the health of the drive. Google and BackBlaze didn’t find any correlation with temperature and drive failures in their study. Microsoft and the University of Virginia on the other hand, found that there was a significant correlation.

Sources:

• https://static.googleusercontent.com/media/research.google.com/en/us/archive/disk_failures.pdf
• https://www.cs.virginia.edu/~gurumurthi/papers/acmtos13.pdf
• https://www.backblaze.com/blog/hard-drive-temperature-does-it-matter/ 

According to a study conducted by Backblaze on their own dataset, 5 SMART attributes seem to be the most important indicators of impending hard drive failure. These attributes are: 

1. SMART 5:  Reallocated Sectors Count
2. SMART 187: Reported Uncorrectable Errors
3. SMART 188: Command Timeout
4. SMART 197: Current Pending Sector Count
5. SMART 198: Uncorrectable Sector Count

Read more about the topic here: https://www.backblaze.com/blog/what-smart-stats-indicate-hard-drive-failures/ 

To change your email follow these steps:

1. Login to your account at https://www.drivenest.com/main/login 
2. On the left panel click the Profile tab
3. At the Personal Info section you can find your current email and change it
4. Click Save Changes to save your new email

To change your password follow these steps:

1. Login to your account from https://www.drivenest.com/main/login 
2. On the left panel click the Profile tab.
3. Change your password from the Change Password section.
4. Click Save Password to save your new password.

We only collect data necessary for monitoring the health of your drive. DriveNest does not collect any sensitive information or any data stored within the drive. 

More specifically, we retrieve the following information:

1. The Node/Machine the drive is reporting from
2. The Vendor of the drive
3. The Model of the drive
4. The SMART attributes of the drive

A snapchot of the data send from the client to the DriveNest server:

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    [0] => smartctl 6.5 2015-10-22 r4159 [i686-w64-mingw32-win10(64)] (daily-20151022)
Copyright (C) 2002-15, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family:     Western Digital Green
Device Model:     WDC WD10EZRX-00A8LB0
Serial Number:    WD-WCC1U2516731
LU WWN Device Id: 5 0014ee 2b2ffc071
Firmware Version: 01.01A01
User Capacity:    1,000,204,886,016 bytes [1.00 TB]
Sector Sizes:     512 bytes logical, 4096 bytes physical
Device is:        In smartctl database [for details use: -P show]
ATA Version is:   ATA8-ACS (minor revision not indicated)
SATA Version is:  SATA 3.0, 6.0 Gb/s (current: 3.0 Gb/s)
Local Time is:    Thu Jun 28 16:37:51 2018 GTBDT
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

=== START OF READ SMART DATA SECTION ===
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   200   200   051    Pre-fail  Always       -       0
  3 Spin_Up_Time            0x0027   139   132   021    Pre-fail  Always       -       4008
  4 Start_Stop_Count        0x0032   098   098   000    Old_age   Always       -       2512
  5 Reallocated_Sector_Ct   0x0033   200   200   140    Pre-fail  Always       -       0
  7 Seek_Error_Rate         0x002e   200   200   000    Old_age   Always       -       0
  9 Power_On_Hours          0x0032   089   089   000    Old_age   Always       -       8256
 10 Spin_Retry_Count        0x0032   100   100   000    Old_age   Always       -       0
 11 Calibration_Retry_Count 0x0032   100   100   000    Old_age   Always       -       0
 12 Power_Cycle_Count       0x0032   098   098   000    Old_age   Always       -       2491
192 Power-Off_Retract_Count 0x0032   197   197   000    Old_age   Always       -       2736
193 Load_Cycle_Count        0x0032   188   188   000    Old_age   Always       -       37099
194 Temperature_Celsius     0x0022   116   107   000    Old_age   Always       -       27
196 Reallocated_Event_Count 0x0032   200   200   000    Old_age   Always       -       0
197 Current_Pending_Sector  0x0032   200   200   000    Old_age   Always       -       0
198 Offline_Uncorrectable   0x0030   200   200   000    Old_age   Offline      -       0
199 UDMA_CRC_Error_Count    0x0032   200   200   000    Old_age   Always       -       0
200 Multi_Zone_Error_Rate   0x0008   200   200   000    Old_age   Offline      -       0


)
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    [0] => /dev/sda
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<br/>Debug= User=demouser <br/>Receiving string..Successfully saved data in: /var/www/www.drivenest.com/htdocs/incoming/g/demouser/516961<br/><br/><br/><br/><br/>User: demouser is currently logged in.<br/><br/></body></html>

When you receive an Impending Drive Failure alert means that our machine learning algorithms have predicted, with a high probability, that your drive is most likely going to fail soon.   

This alert doesn't mean that your drive is certainly going to fail. It has basically detected a similarity between your drive and other drives that have failed in the past.   

You can either chose to ignore this alert or take precautions. For example, since you know that your drive might be failing soon, you can back up your data to avoid losing it, if and when the drive ceases to work.

1. Head to the Login Page
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6. Click the link included in the email.
7. The TAN field must now contain a generated key. 
8. Type in your new password
9. Click Save Password to save your new password

Direct Way:

1. Click the earth icon from the main menu at www.drivenest.com 
2. Select Register
3. Type in your user name, password and email
4. Click Register Now
5. You must receive a new email to the email account you have provided. Click the link included in the email to active your account.

Indirect Way:

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2. Select Create an account
3. Type in your user name, password and email
4. Click Register Now
5. You must receive a new email to the email account you have provided. Click the link included in the email to active your account.

To download the drivenest client follow these steps:

1. Log in to your account.
2. After log in, a new menu apears at the top. Select the download tab
3. Click on the link corresponding to your operating system
4. Extract the downloaded file and you're ready to go!

No. The drivenest client only sends text files periodically to the server, meaning that the bandwidth used by the client is negligible. 

You can control how often a client sends data to the server by adjusting the Submission Interval from the graphical user interface of the client. 

The Python DriveNest Client  (pyDriveBird) is the open-source SMART data submission client developed and maintained by the DriveNest team. The power of pyDriveBird is that it can be configured to collect SMART data from remote hosts, in addition to local drives. There is no need to install a different client on each machine that has to be monitored. It is also possible to monitor the health of disk drives of multiple disparate networks, or collect SMART data from a private or secure network, that does not have direct access to the Internet.

This client can be used on most systems that python and smartmontools run on, these include Linux, FreeBSD,  NetBSD, OpenBSD, Darwin (Mac OS X), Solaris, OS/2, Cygwin, Windows.

Getting started

To use the Python DriveBird client you need three preparation steps:

1. A Web Account on the DriveNest. Please register one at https://www.drivenest.com
2. You need smartmontools (http://www.smartmontools.org)
3. A working Python installation

Windows Installation

Once you have created your DriveNest Web Account at https://www.drivenest.com
download and install smartmontools. Choose the latest version from:

 http://sourceforge.net/projects/smartmontools/files/smartmontools/

Next download and install Python 2.x (or 3.x) for Windows:

https://www.python.org/downloads/windows/

You can then execute from a command prompt: python pyDriveBird.py -h for possible options.
There is a one-time client activation, which you have to perform: python pyDriveBird.py -a
Activation will ask for your Web Account username and password. This will activate the client
which will allow it to send SMART information to the DriveNest that can be then viewed on the
web. The Web Account information is NOT stored on your system to prevent from someone obtaining
and accessing your DriveNest Web Account. The client can ONLY send SMART data, no other access
is possible after activation.

To send SMART information you just execute: python pyDriveBird.py (without arguments)
By default all your (supported) drives will be scanned. If you want to tweak and customize
which drives you want to monitor then read the information in section DriveBird Layout.

Attention: Please ensure that smartmontools (smartctl) works properly, as it may require
Administrator access.

You can verify this by executing: smartctl --scan-open

If you see "Permission Denied" in the output, you need to give it permissions or run DriveBird
under an administrative account.

Linux Installation

Once you have created your DriveNest Web Account at https://www.drivenest.com
install smartmontools using your distribution's software management. We provide some details for
popular distributions below.

On Debian/Ubuntu/Mint: $ sudo apt-get install smartmontools
On Fedora/CentOS: $ sudo yum install smartmontools
On openSUSE: $ sudo zypper in smartmontools
On Arch Linux: $ sudo pacman -S smartmontools
On Gentoo: $ sudo emerge sys-apps/smartmontools

 If you need to enable a user sudo access for smartctl (which is highly recommended, then
insert the following lines in your /etc/sudoers:

 Defaults:username !authenticate
 username ALL=(ALL) NOPASSWD:/usr/sbin/smartctl

 The first line enables the user "username" to ONLY execute /usr/sbin/smartctl
 They are not provided an option to insert a password which by default would let
 them execute other specified commands in sudoers.

 Mac OS X Installation

You can install smartmontools using MacPorts: # port install smartmontools