Badblocks that new disk

First thing first, running badblocks will wipe the entire disk. Make sure that there is no data on the disk before running badblocks. Also, if you have mulitple disks, make sure to select the correct disk to avoid data loss.

Since I started using Unraid in 2016, the Unraid community recommends to Pre-clear (burn-in test) the disk first before adding it to the array. The reason being it is better it to fail during the test than having it fail with user data on the disk. At my work, we had to RMA several brand new disks because they were DOA.

There is this term called Infant mortality. It means that hard drives are prone to fail during its first couple of months of usage due to some manufacturing defect that was not detected by the vendor. These defects could manifest after a few weeks or months of usage. Therefore, running a burn-in test decreases the chance of encountering one. However, it does not eliminate of getting a faulty disk.

From what I read, some folks run their burn-in test a couple of times just to make sure, I ran mine only one time, it is a risk I am willing to take for now. A 12TB Western Digital Easystore took ~164 hours on USB 3.0. Yes, I didn’t want to schuck it and find out it was bad.

There is an easy way of doing this whole thing via this git repository and you may need to install ksh. Badblocks can only run one disk at a time. You can open a new terminal and run another instance. I use tmux to accomplish this. Anyways, to run the manual process, it goes like this:

  1. Run SMART short test
  2. Run badblock
  3. Run SMART long test

Badblock and SMART usually come with most distros, but if they are not.

# Badblock should already be installed, but if it is not
# To install badblocks
dnf install e2fsprogs # CentOS/Fedora/RHEL
apt install e2fsprogs # Debian

# To install SMART
dnf install smartmontools # CentOS/Fedora/RHEL
apt install smartmontools # Debian

To identify the target disk, we can use tools such as lsblk, fdisk and smartctl. We can use a serial number or the device ID. Either way, the device needs to be identity. In my case, it is the /dev/sde.

# lsblk
lsblk -d -o name,serial,type,tran
sda  DB82736F2414E        disk usb
sdb  5F903100152051619201 disk usb
sdc  YJK80ZDL             disk sas
sdd  LPF920ZL             disk sas
sde  WD-UJKEW0129914      disk sas

# fdisk
fdisk -l
...output omitted for brevity...

smartctl -a /dev/sde | grep Serial
Serial Number:    WD-UJKEW0129914

If you are running SMART on a USB device as I did, I have to specify the device type to sat; otherwise, SMART will complain that it cannot recognize the drive.

smartctl /dev/<device> -d sat

To run the SMART short test

smartctl -t short /dev/sde -d sat
smartctl 6.6 2017-11-05 r4594 [x86_64-linux-4.18.0-193.19.1.el8_2.x86_64] (local build)
Copyright (C) 2002-17, Bruce Allen, Christian Franke,

Sending command: "Execute SMART Short self-test routine immediately in off-line mode".
Drive command "Execute SMART Short self-test routine immediately in off-line mode" successful.
Testing has begun.
Please wait 2 minutes for test to complete.
Test will complete after Tue Nov  3 07:44:48 2020

Use smartctl -X to abort test.

The SMART test runs in the background. To check that status of SMART test.

# SMART test is still running
smartctl -a /dev/sde -d sat | grep execution
Self-test execution status:      ( 241) Self-test routine in progress...

# SMART test completed
smartctl -a /dev/sde | grep execution
Self-test execution status:      (   0) The previous self-test routine completed

Now, that we identified the device and tested for SMART short test, we need to run badblocks. Here are the parameters.

  • -b option specifies the block size that could improve the burn-in time. The default is 1024
  • -c is the number of blocks which are tested at a time. The default is 64.
  • -w option use destructive write test
  • -s option shows progress
  • -v option is verbose mode
  • -o option is output file. Without the -o badblocks will simply use the STDOUT
badblocks -b 32768 -c 512 -wsv /dev/sde -o wd-black-750g.txt

The burn-in test will go through the patterns of 0xAA, 0x55, 0xFF then 0x00 as shown below.

badblocks -b 32768 -c 512 /dev/sde -wsv -o wd-black-750g
Checking for bad blocks in read-write mode
From block 0 to 22892954
Testing with pattern 0xaa: done
Reading and comparing: done
Testing with pattern 0x55: done
Reading and comparing: done
Testing with pattern 0xff: done
Reading and comparing: done
Testing with pattern 0x00: done
Reading and comparing: done
Pass completed, 0 bad blocks found. (0/0/0 errors)

Once badblocks is done and there is no error, run the SMART long test

smartctl -t long /dev/sde -d sat

If everything looks good, then the drive is a keeper otherwise, if it is returnable return it or RMA it.


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