I have created a centos 7 VM on VMWare vspher ESX server.
I have not attached serial port to this VM to begin with.
But I still need to enable /dev/ttyS0.
How can achieve this? I remember on Centos 6 it was working fine even without attaching serial port.
Any operations I do on /dev/ttyS0 results in ttyS0: input/output error.
dmesg | grep tty only shows:
console [ttyS0] enabled.
But if I attach a serial port to this VM, ttyS0 works just fine.
Then, the dmesg | grep tty shows:
I tried even playing with systemd files like serial-getty@ttyS0.service but no luck!console [ttyS0] enabled.
ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A <---- this tells me that somewhere ttyS0 is now mapped(?) to some pci irq slot which was not happening in the above case.
If I try to start the serive serialgetty@ttyS0, agetty gives error as "/dev/ttyS0 is not a character device."
Could someone please help me?
Thanks in advance.