mount exist hard disk in debian

check if the drive is exist or not :
fdisk -l
if the disk is there
check if the partition is mounted or not
df -h
if the disk exist and not partitioned yet , then you have to do so using :

fdisk /dev/sdb1

mkdir /newstorage
chmod 755 /newstorage

mkfs.ext4 /dev/sdb1

mount /dev/sdb1  /newstorage 

Add this line to /etc/fstab

/dev/sdb1  /newstorage ext4 defaults 0 10

mount /newstorage 

 OR

mount -t ext4 /dev/sda1 /newstorage