- Device /dev/modem Access Failed: No Such File Or Directory
An Error You Might Get In Linux When You Try To Start Minicom Device /dev/modem Access Failed: No Such File Or Directory. 
Fri Jan 22, 2010
Welcome to Webune Support
Webune Provides Linux Dedicated Servers.
If you have a Linux Dedicated server, you might expirience this error when you try to access your cisco firewall, router or switch when you try to console into the device from the dumb terminal from your server.
if you are logged in as root and you try to start minicom, you might get this error so be sure you configure it first with these settings:
Serial Device : /dev/ttyS0
│ A - Serial Device : /dev/ttyS0 │
│ B - Lockfile Location : /var/lock │
│ C - Callin Program : │
│ D - Callout Program : │
│ E - Bps/Par/Bits : 9600 8N1 │
│ F - Hardware Flow Control : Yes │
│ G - Software Flow Control : No │
│ Change which setting? │
as you can see from my configuration, the 'Serial Device' settings are: /dev/ttyS0 to be sure to change that from '/dev/modem'
if you need more help on how to configure and save the settings go to this post:
configure cisco switch with linux COM1 terminal
let me know if that works for you