Check disk

BASIC CHECK

See what you have. Use gparted, or these...

# basics
df
# NICE, this shows ALL DRIVES and where they are mounted!
sudo lsblk
# This is nice too, shows "data" for a raw drive, or type for a formatted one.  Nice to know!
sudo file -s /dev/xvdf

Most drive health maintenance is done internally by S.M.A.R.T.

# install smartctl tools
smartctl -c /dev/sdf # to peek at available tests and how long they typically take to run
smartctl -t short /dev/sdf
watch -n 3 smartctl -l selftest /dev/sdf # until success, takes about 1 minute
# if you're feeling ambitious, rerun with [-t long]

HEAVIER READ-WRITE TEST

You can do more (but it's more dangerous as you'll be writing a LOT). Boot to a live mode to test root partitions.

plug it into the SSD usb mounter, but don't mount
sudo e2fsck -c -c /dev/sda1 # non-destructive read/write, takes 8 hours on 8TB drive

NUKING AND REFORMATTING AND TESTING A DRIVE

This can be done for new drives, or old drives that need a complete refresh.

DIRECT NUKE TEST

badblocks is an old program that destructively scans an entire drive (like dd) looking for bad blocks, by writing data to them all (which MAY cause firmware to improve things...?). You have to use -b param to get it to work with larger drives. THIS IS DESTRUCTIVE:

sudo badblocks -t random -w -svv -b 4096 /dev/sda

e2fsck should be preferred according to [man badblocks] (see next test). But if you can't get a partition written you will need badblocks. OR IF YOU ARE IN A HURRY. :-)

TEST VIA WIPING AND CREATING A NEW PARTITION

plug it into the SSD usb mounter
sudo fdisk /dev/sda
p
d # to remove any existing partition
n # to create new one, use defaults to make /dev/sda1
w
sudo mkfs.ext4 /dev/sda1
sudo mount -t ext4 -o rw /dev/sda1 /mnt/sda1 # ensure it mounts
sudo umount /mnt/sda1
sudo e2fsck -c -c /dev/sda1 # non-destructive read/write, takes 8 hours on 8TB drive