to mount a disk in linux

all devices are listed as files in /dev

e.g. $ ls -l /dev
for a list of all devices in /dev

to filter it down to devices containing the string 'sda'
$ ls -l /dev | grep -i sda

which for example returns

ptysd
sda
sda1
sda2
sda5
sdb
... and more

then
$ sudo fdisk -l /dev/sda

fdisk in this case yields partition information for the device
fdisk --help for usage

also
$ cat /var/log/messages