Do one thing and do it well.Unix Philosophy
This article describes a tool for testing your HDD on a daily basis and how can you fill it completely with zeros or random numbers to check it for broken sectors.
I was spending a whole day installing and configuring 4 different operating systems on my new Desktop PC - didn’t virtualize my Windows because I wanted to use it for gaming (especially Fallout 3). After four weeks the disasters happened: My hard disk drive was broken. Before spending a whole installing your new systems, it is worth spending a day to check your new HDD (Hard Disk Drive).
Symptoms of a breaking HDD
If you encounter any of the following things you can be sure that your HDD will break soon:
- working with Blue Screens and occasionally system fall downs
- problems with installing new OS - even on Knoppix
- overwriting the harddisk completely
- blinking LED even if you are not working - is a sign that the HDD disk is writing the content into still valid sectors
Checking your new HDD with smartools
Smartmontools is an analysis tool for Linux/Unix systems which allows you
to check your hard disk - even on your regular usage. The program consists of two parts:
smartctl (checking and
evaluating HDD parameters) and
smartd (is daemon to check your HDD on a regularly state).
Install the tool with the following command:
$ sudo apt-get install smartmontools
Using smartctl for HDD diagnosing
To get an overview of your new HDD please perform:
$ sudo smartctl -H /dev/sda
Important of the output is the parameter “passed”, it tells you that the test is over:
smartctl 5.41 2011-06-09 r3365 [i686-linux-3.2.0-23-generic] (local build) Copyright (C) 2002-11 by Bruce Allen, http://smartmontools.sourceforge.net === START OF INFORMATION SECTION === Device Model: ST500DM002-1BD142 Serial Number: Z2ARNP4C LU WWN Device Id: 5 000c50 04079c23c Firmware Version: KC45 User Capacity: 500,107,862,016 bytes [500 GB] Sector Sizes: 512 bytes logical, 4096 bytes physical Device is: Not in smartctl database [for details use: -P showall] ATA Version is: 8 ATA Standard is: ATA-8-ACS revision 4 Local Time is: Thu Jul 12 06:54:59 2012 CEST 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: ( 600) seconds. Offline data collection capabilities: (0x7b) SMART execute Offline immediate. Auto Offline data collection on/off support. Suspend Offline collection upon new command. Offline surface scan supported. Self-test supported. 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: ( 1) minutes. Extended self-test routine recommended polling time: ( 81) minutes. Conveyance self-test routine recommended polling time: ( 2) minutes. SCT capabilities: (0x303f) SCT Status supported. SCT Error Recovery Control supported. SCT Feature Control supported. SCT Data Table supported. SMART Attributes Data Structure revision number: 10 Vendor Specific SMART Attributes with Thresholds: ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE 1 Raw_Read_Error_Rate 0x000f 107 099 006 Pre-fail Always - 12627760 3 Spin_Up_Time 0x0003 100 100 000 Pre-fail Always - 0 4 Start_Stop_Count 0x0032 100 100 020 Old_age Always - 76 5 Reallocated_Sector_Ct 0x0033 100 100 036 Pre-fail Always - 0 7 Seek_Error_Rate 0x000f 064 060 030 Pre-fail Always - 2705616 9 Power_On_Hours 0x0032 100 100 000 Old_age Always - 84 10 Spin_Retry_Count 0x0013 100 100 097 Pre-fail Always - 0 12 Power_Cycle_Count 0x0032 100 100 020 Old_age Always - 74 183 Runtime_Bad_Block 0x0032 100 100 000 Old_age Always - 0 184 End-to-End_Error 0x0032 100 100 099 Old_age Always - 0 187 Reported_Uncorrect 0x0032 100 100 000 Old_age Always - 0 188 Command_Timeout 0x0032 100 100 000 Old_age Always - 0 189 High_Fly_Writes 0x003a 100 100 000 Old_age Always - 0 190 Airflow_Temperature_Cel 0x0022 061 049 045 Old_age Always - 39 (Min/Max 22/39) 194 Temperature_Celsius 0x0022 039 051 000 Old_age Always - 39 (0 21 0 0) 195 Hardware_ECC_Recovered 0x001a 045 039 000 Old_age Always - 12627760 197 Current_Pending_Sector 0x0012 100 100 000 Old_age Always - 0 198 Offline_Uncorrectable 0x0010 100 100 000 Old_age Offline - 0 199 UDMA_CRC_Error_Count 0x003e 200 200 000 Old_age Always - 0 240 Head_Flying_Hours 0x0000 100 253 000 Old_age Offline - 110127256436820 241 Total_LBAs_Written 0x0000 100 253 000 Old_age Offline - 3616779477 242 Total_LBAs_Read 0x0000 100 253 000 Old_age Offline - 1189576021 SMART Error Log Version: 1 No Errors Logged SMART Self-test log structure revision number 1 Num Test_Description Status Remaining LifeTime(hours) LBA_of_first_error # 1 Conveyance offline Completed without error 00% 2 - # 2 Extended offline Aborted by host 90% 2 - # 3 Conveyance offline Completed without error 00% 2 - # 4 Short offline Completed without error 00% 1 - # 5 Extended offline Aborted by host 40% 1 - # 6 Short offline Aborted by host 80% 1 - 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.
You can perform longer tests of your harddisk with:
$ sudo smartctl -t long /dev/sda
Depending on the size of your HDD, it takes some time. For checking a whole 500 GB the program runs about 80 minutes.
It is even possible to check if your HDD has damage incurred during transporting the drive with the
$ sudo smartctl -t conveyance /dev/sda
Performing long time diagnostic with smartd
The first step is to give the daemon the permission to run checks in the background:
$ vim /etc/default/smartmontools > start_smartd=yes
Find the line with and uncomment it:
# uncomment to start smartd on system startup¬ #start_smartd=yes¬
The configuration file for the daemon can be found under
/etc/smartd.conf. Here only one line is sufficient to check
DEVICESCAN -m root@<your-os-name> -M exec /usr/share/smartmontools/smartd-runner
Let’s get through each line step-by-step:
DEVICESCAN: will scan all HDDs in the range between
/dev/hd[a-I] .. /dev/sd[a-z], which support SMART
-m firstname.lastname@example.org: in case of an error, an email will be sent to this address
-M: the frequency of emails departure
-M exec: don’t send testmails
-M test: send a testmail (when using this option, you must leave out the
-M daily: send daily reports
Now it’s time to test our configuration:
$ smartd -q onecheck
You can check your internal mails with
$ sudo mail (you need install Postfix on your OS)
and rebooting the daemon:
If you want to have a graphical client for this tool, you need to run:
$ sudo apt-get install gsmartcontrol
You need then to start the program in sudo mode to detect all HDDs
Checking the whole space on your HDD
You know these tiny small
dd commands? No, it’s time to learn and understand them. They are very handy to fill your
your whole HDD with lovely zeros and ones.
dd stands for data definition. It has direct access on the harddisk and can read boot sectors - it is even used to
create iso files of CDs.
Writing zeros or random numbers
$ dd if=/dev/zero of=/dev/sda
Take from the input file (
if) the zeros (
/dev/zero) and write them on the output file (
the command has written the whole hard disk, it will end.
Speeding up the process with faster writing
Normally, each block of the hard disk has the size of 512 KB. To set the blocksize on 1 MB (1024 KB), we can speed up
the writing speed with the factor two. We can achieve do this with the
$ dd if=/dev/zero of=/dev/sda bs=1024
Jump over errors
dd will end, if it detects a broken sector. With the
dd will write till the HDD is full even
over broken sectors:
$ dd if=/dev/zero conv=noerror of=/dev/sda bs=1024
Other useful parameters are
notrunc (write the output file completely) or
sync (write with the full length).
Running the dd command with status display
We can use the pv command to monitor the progress of data through a pipe. First we need to install it:
$ sudo apt-get install pv
To get an overview about how many MB or GB have already be written, use the following command:
$ dd if=/dev/random conv=notrunc,sync bs=1024 | pv > /dev/sda
A broken HDD is a bad thing, but if you know the symptoms it saves you a lot of time because you you know that you have to buy new hardware. Always have backup on an external HDD so that you can easily replace you data.
It is good to run a couple of tests before you start implementing your whole system.