The standard method to access z/VM is using a 3215 terminal with a terminal emulator. With linux, the x3270 package provides a free emulator for these terminals.
One of the features of z/VM is, that you can define several consoles for a guest. This is very helpful if there are problems with a guest that affect the network connectivity. With z/VM you can even define multiple consoles that allow direct logon to the running guest.
By default, only one terminal is defined for z/VM guests. To define three additional 3270 consoles on a guest at the addresses 0020-0022, use the following commands:
cp define graf 20 cp define graf 21 cp define graf 22
These consoles can also be created online from linux, provided that you got sufficient privileges on the guest. To issue
cp commands from linux, use the command
vmcp instead of
With SLES 12, several additional steps are needed to activate these consoles.
First, the devices must be made available to the system. This a twofold process:
- Remove the devices from the cio ignore list with the command
- Add the devices to /boot/zipl/active_devices.txt to make this change persistent.
# cat /boot/zipl/active_devices.txt ... 0.0.0020-0.0.0022
cio_ignore -r 0.0.0020-0.0.0022
The system automatically detects those devices. The corresponding serial devices are found below
/dev/3270/tty. Next, tell
systemd to run a getty on these devices:
systemctl enable email@example.com systemctl enable firstname.lastname@example.org systemctl enable email@example.com systemctl start firstname.lastname@example.org systemctl start email@example.com systemctl start firstname.lastname@example.org
To use the new consoles on a machine called LINUX065, direct the 3270 terminal emulator at z/VM. Instead of logging on as regular user, move the cursor to the
COMMAND line and enter the following command:
To redisplay the logon prompt, you might want to press enter once.
When trying to logon to this console as root, you will find that it won’t let you. The reason for this is, that root logon is only allowed on previously defined consoles. The configuration file for this is
/etc/securetty. Add the following lines to the end of this file:
3270/tty1 3270/tty2 3270/tty3
After this, you can directly logon to the linux guest without the need for z/VM credentials.
If you want to avoid the need to redefine the consoles after a logoff of the guest, add the definition to
PROFILE EXEC A of the guest.