====== Disk or Flash Drive Testing and Preparation ======

===== Testing =====

  * Testing best done with direct connection - USB connections are really slow and not fully functional (smart)
  * Check for I/O errors in /var/log/messages
  * Install  'smartmontools' package
  * http://smartmontools.sourceforge.net/badblockhowto.html
  * http://www.cyberciti.biz/tips/monitoring-hard-disk-health-with-smartd-under-linux-or-unix-operating-systems.html
  * man smartctl for many options/disk/controller types
  * Typically, you need to dismount the filesystems on the drives to be tested

==== SMART ====

Disks support smart?
<file>
sudo smartctl -i /dev/sdX

</file>
Show disk info:
<file>
sudo smartctl -a /dev/sdX
</file>

Enable smart:
<file>
sudo smartctl -s on -d ata /dev/sdX
</file>

Initiate quick health check:
<file>
sudo smartctl -d ata -H /dev/sdX
</file>

Initiate extended self test:
<file>
sudo smartctl -d ata -t long /dev/sdX
</file>
then
<file>
sudo smartctl -l selftest /dev/sdX
</file>

==== Badblocks ====

:!: Badblocks can be hazardous to your data.  **Make a backup first!**

:!: Running ''badblocks'' on **SSDs** may **reduce lifespans**.

There are some valid circumstances where you have to use the '-f' switch to force the testing.  Be careful when doing so to make sure you 'do no harm'.

=== Determine Optimal Block Size ===

<file>
tune2fs -l /dev/sdX1 | grep Block
</file>

=== Non-Destructive Test ===

Read/write test a disk/partition:

<file>
sudo badblocks -nvs /dev/sdX                # entire disk
sudo badblocks -nvs /dev/sdX1               # partition only
</file>

=== Destructive Test ===

This is the best test and uses 4096K blocks for improved speed and saves a log file of bad blocks (add f to -wvs to force if drive reports in use):

<file>
sudo badblocks -wvs -b 4096 /dev/sdX | tee badblocks.txt
</file>

===== Preparation =====

==== Wipe a Disk ====

Write zeros to disk (best for making compressible images) (also wipes out MBR):
<file>
sudo sh -c "cat /dev/zero > /dev/sdX"
</file>

==== Partition a Disk ====

Show disks:
<file>
sudo fdisk -l
</file>

Partition a drive:
<file>
sudo fdisk /dev/sdX
</file>

==== Write a DOS MBR ====

Write a DOS MBR (like fdisk /MBR) (may need --force)
<file>
sudo install-mbr /dev/sdX -v --interrupt n --partition D --timeout 0
</file>

Note: the syslinux package also includes a mbr.bin file:
<file>
sudo dd if=/usr/lib/syslinux/mbr.bin of=/dev/sdX
</file>

==== Make a Filesystem ====

Linux EXT3:
<file>
sudo mkfs.ext3 /dev/sdX1
</file>

FAT32 (Flash is normally FAT16 or FAT32):
Partition the flash device as 'W95 FAT32' and set the 'bootable' flag if desired.
<file>
sudo mkdosfs -F 32 /dev/sdX1
</file>
or
<file>
sudo mkfs.vfat -F 32 /dev/sdX1

</file>