How to Check Out Your Dedicated Server’s Hard Drive

With the rise of Chia farming, many hard drives provisioned in LowEnd dedicated servers are arriving having suffered phenomenal (ab)use.  Sure, your dedi provider is usually on the hook to replace if your drive dies, but who wants to go through that kind of hassle and disruption?

Here’s a quick technique for checking what state your hard drive is.  Note that this method works only on dedicated servers where you have true access to your physical hard drive.  It does not work on virtual servers, where the storage is virtualized.

Hard drives include an on-board monitoring system called S.M.A.R.T (Self-Monitoring, Analysis and Reporting Technology) which can “detect and report various indicators of drive reliability with the intent of anticipating imminent hardware failures.”  Various statistics and data are kept on-board and you can query these to obtain information that will tell you about the drive’s history.

To begin with, install the smart-tools package.  For example, on Debian systems:

apt-get install smartmontools

Next, query the drive in question:

smartctl -a /dev/sdg

For example, here is a report of a nearly new (less than 72 hours use) Western Digital 6TB Black SATA drive:

# smartctl -a /dev/sdg
smartctl 6.6 2016-05-31 r4324 (x86_64-linux-4.9.0-16-amd64) (local build)
Copyright (C) 2002-16, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Device Model:     WDC WD6003FZBX-00K5WB0
Serial Number:    V9JGEZSL
LU WWN Device Id: 5 000cca 0bde2c0ba
Firmware Version: 01.01A01
User Capacity:    6,001,175,126,016 bytes (6.00 TB)
Sector Sizes:     512 bytes logical, 4096 bytes physical
Rotation Rate:    7200 rpm
Form Factor:      3.5 inches
Device is:        Not in smartctl database (for details use: -P showall)
ATA Version is:   ACS-2, ATA8-ACS T13/1699-D revision 4
SATA Version is:  SATA 3.2, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is:    Sun Jul 11 11:52:27 2021 PDT
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:  (0x82) Offline data collection activity
 was completed without error.
 Auto Offline Data Collection: Enabled.
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: (   87) 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:  ( 593) minutes.
SCT capabilities:        (0x0035) SCT Status 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     0x000b   100   100   016    Pre-fail  Always       -       0
  2 Throughput_Performance  0x0004   133   133   054    Old_age   Offline      -       92
  3 Spin_Up_Time            0x0007   100   100   024    Pre-fail  Always       -       0
  4 Start_Stop_Count        0x0012   100   100   000    Old_age   Always       -       1
  5 Reallocated_Sector_Ct   0x0033   100   100   005    Pre-fail  Always       -       0
  7 Seek_Error_Rate         0x000a   100   100   067    Old_age   Always       -       0
  8 Seek_Time_Performance   0x0004   128   128   020    Old_age   Offline      -       18
  9 Power_On_Hours          0x0012   100   100   000    Old_age   Always       -       69
 10 Spin_Retry_Count        0x0012   100   100   060    Old_age   Always       -       0
 12 Power_Cycle_Count       0x0032   100   100   000    Old_age   Always       -       1
192 Power-Off_Retract_Count 0x0032   100   100   000    Old_age   Always       -       4
193 Load_Cycle_Count        0x0012   100   100   000    Old_age   Always       -       4
194 Temperature_Celsius     0x0002   141   141   000    Old_age   Always       -       39 (Min/Max 25/41)
196 Reallocated_Event_Count 0x0032   100   100   000    Old_age   Always       -       0
197 Current_Pending_Sector  0x0022   100   100   000    Old_age   Always       -       0
198 Offline_Uncorrectable   0x0008   100   100   000    Old_age   Offline      -       0
199 UDMA_CRC_Error_Count    0x000a   200   200   000    Old_age   Always       -       0
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 1
 SPAN  MIN_LBA  MAX_LBA  CURRENT_TEST_STATUS
    1        0        0  Not_testing
    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.

Here are some areas in the report to look at:

Power_On_Hours: This will give you the total hours the drive has been powered on.  This does not mean necessarily in use, but rather it was spun up and receiving electricity.

Power_Cycle_Count: How often has the drive been power cycled?

Raw_Read_Error_Rate, Seek_Error_Rate, Offline_Uncorrectable: these should ideally be zero.

Reallocated_Event_Count: Ideally this should be zero or a very low number.

SMART overall-health self-assessment test result: not surprisingly, you want this to say PASSED.  

If you receive a drive whose age indicates it’s several years old, or has many errors, you may wish to contact your dedi provider and ask for a preventative replacement rather than risk failure.

raindog308

I’m Andrew, techno polymath and long-time LowEndTalk community Moderator. My technical interests include all things Unix, perl, python, shell scripting, and relational database systems. I enjoy writing technical articles here on LowEndBox to help people get more out of their VPSes.