Cannot open /dev/ttyS0: Device or resource busy

[pichi]

hi eveybody, i have a redhat 8.0 server installed, i use wvdial to connect my server to the internet, when i execute wvdial with user root there is no problem, but i want that other users can execute the wvdial program and connect to the internet, but when they try to execute wvdial they got thos error
Cannot open /dev/ttyS0: Device or resource busy
it a serial modem, and i asign the file permision to the /etc/wvdial and /dev/ttyS0 to one of my user so i can test it, but i got the same error, does anyone knows what i am doing wrong, or where is a aditional config o system file for that? thanks in advance
ahh i almost forgot i have already add the one of my users to the root group at the /etc/group file.
thanks
Pichi

 

[sco21]

Try as the ather user to open /dev/ttyS0 with minicom

minicom -s to set the parameters ---> port ttyS0 speed 115200

see if you have the same error again...try to dial someone
or your ISP manually atdt........ login...bla pass...bla

ctrl +a z then q to quit without reset

and run the pppd daemon

see what happeneds =-=-=-=-=-=-=-=-=-=-=-=
Unix Systems Engineer
=-=-=-=-=-=-=-=-=-=-=-=

 

[timsr]

What are you using to open the device, cu? If so, you need to change the permissions on cu and uucp. We use cu and uucp all the time and the device or resource busy is a comman error. Change both cu and uucp in usr bin to 2755. Also the device file needs to be crw-rw-rw with a group that is common to all that use the device. There is a flaw or design error in that when a user grabs the device, it quite often changes the owner, group and permissions on the device file. We wrote code to compensate for this in our software.