External hard drive

UNIX for Advanced & Expert Users
1

I have connected an external hard drive. I can't find it.
Both

ls /media, fdisk -l and ls /dev

show nothing.

TIA

2

What OS and version?
Usually Unix has utilities used to scan and discover new HW (and create the device if non existent ) like insf (HP-UX) or cfgmgr (AIX)

3

Or if it's Solaris:

 
 # rmformat -l
4

My experience is with older stuff but this is what was required:
Since there is no hardware link to a new device the first step is to create it"

mkdev hd

which creates the link in /dev
Then create the identity for the file systems you want on it:
In my case

divvy /dev/hdx

creating names and sizes
And last, creating the file system(s) and mount points:
In my case

mkdev fs

for each file system you created earlier. My systems had provisions for the formatting and mounting conditions as part of this. Since you are doing this for a removable unit you wouldn't want to automatically mount it unless you are planning to reboot each time you make a change.