External Serial Connector Remote Access Device
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Jan 21, 2005 Troubleshooting modems. Connections reports that a port is in use or not configured for remote access. the serial port speed or the device speed.
Connecting to a Remote Serial Port over To access a remote serial port, This will then allow you to specify /dev/ttyV0 as the device name in an application.
Serial Port Console Redirection
If you need to access remote serial port over network, It will help you to access COM device over LAN/Ethernet/Internet. Serial to Ethernet Connector.
- Use Serial server to communicate with serial devices over Connect to remote serial device over network. Access local to serial port devices.
- Allows you to associate the external serial connector to serial device 1, serial device 2, or remote access device. Serial Device 2 COM2. External Serial Connector.
- Accessing USB Devices in Remote Desktop Session. To access shared USB device in remote desktop session, Serial to Ethernet Connector for Windows.
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Dell OpenManage Baseboard Management Controller Utilities User s Guide
Serial Communication
SPCR Table
Serial Console redirection With SOL Proxy
Serial Communication
For PowerEdge x9xx and xx0x servers, serial console redirection can be accomplished using COM1 or COM2.
Console Redirection Via COM1
To activate serial console redirection via COM1, you must configure the following settings:
Set Serial Communication- Serial Communication to On with Console Redirection via COM1
Set Serial Communication- External Serial Connector to COM1
Console Redirection Via COM2
Console Redirection via COM2 can be used to redirect either to the external connector or to the remote access device, such as a BMC or DRAC 5, for Serial Over LAN SOL communication.
To activate serial console redirection via COM2, you must configure the following settings:
Set Serial Communication- Serial Communication to On with Console Redirection via COM2
Set Serial Communication- External Serial Connector to COM2
NOTE: If the console redirection is used for SOL then the External Serial Connector setting does not need to be configured.
When using COM2 for console redirection regardless of whether you redirect to the external connector or for SOL, the BIOS reads the SOL baud rate from the BMC and uses that setting to activate console redirection. SOL baud rate can be configured using the Dell Deployment Toolkit, OMSA, DRAC, or the BMU.
Serial Terminal Communication to BMC or DRAC
Serial Terminal Mode allows you to directly connect to the BMC or DRAC using a serial port connection and execute text-based commands. Refer to the Appendix B for information about configuring your BMC and DRAC for Serial Terminal Communication as well as available Terminal Mode Commands.
In Terminal Mode, the BMC or the DRAC, if present, support Escape key sequences that allow switching between the Serial Terminal Connection and the connection to the system COM2 port. This can be combined with the Console Redirection via COM2 see Console Redirection Via COM2 to switch between viewing the system console redirection and communicating to BMC or DRAC to execute the terminal commands such as system reset.
NOTE: For this combined functionality, Serial Communication baud rate and the SOL baud rate must be set to the same value.
When in terminal mode, to switch the connection to the system COM2 port use:
Esc Shift q
When connected to the system COM2 port, to go back to the terminal mode use:
Esc Shift 9
SPCR Table
The Serial Port Console Redirection SPCR table provides information about how the system firmware and service processor use the out-of-band OOB management port. For example, if the OOB Management port is a serial port, the SPCR table contains information such as serial port number, baud terminal type, and other settings used for OOB communication. The SPCR table is read by the Special Administrative Console SAC for console redirection and configures itself automatically during a bootable CD installation.
The SPCR table is automatically enabled if the system service processor supports Emergency Management Services EMS such as console redirection. If it is not configured automatically, you must configure SPCR to match BMC settings by adding the following parameters to the unattend.txt file.
NOTE: The
unattend.txt file is automatically created after installation.
Data
EMSPort
EMSBaudrate
Where,
EMSPort Port used for serial communication. For example, COM1 or COM2.
EMSBaudrate Configured baud rate for communication. The minimum supported baud rates for supported Dell PowerEdge systems is 19200.
Serial Console redirection With SOL Proxy
Configuring Linux for Serial Redirection During Boot
The SysRq key is a key sequence that allows basic commands to be passed directly to the kernel for debugging. Under some circumstances, it can also be used to reboot remote managed systems. The serial console uses the RS-232 break function as the SysRq key. A break is a period of no transmission on the serial line. To configure the Sysrq key in systems running Linux, follow the instructions given below:
NOTE: The following instructions are specific to the Linux GRand Unified Bootloader GRUB. Similar changes would be necessary for using a different boot loader.
NOTE: In configuring the client VT100 emulation window, you must set the window or application that is displaying the redirected console to 25 rows x 80 columns to ensure proper text display; otherwise, some text screens may be garbled.
Edit the file /etc/grub.conf, as follows. See the sample file that follows, which shows the changes described in this procedure.
Add the following two new lines in the
general settings section of the file:
serial --unit 0 --speed 19200
terminal --timeout 10 serial
Append two options to the kernel line:
kernel. console ttyS0,19200
If the /etc/grub.conf contains a
splashimage directive, you must
comment it out.
This sample file, using a baud rate of 19200, is an example. The following maximum baud rates are allowed for BMC serial communication and SOL:
19200 for PowerEdge 1425SCandotherPowerEdge
x8xx systems.57600 for PowerEdge
x9xx and systems without Dell Remote Access Controller 5 DRAC 5. 115200 for PowerEdge
x9xx and systems with DRAC 5.
Table D-1.
Sample File: /etc/grub.con
grub.conf generated by anaconda
Note that you do not have to rerun grub after making changes to this file
NOTICE: You do not have a /boot partition. This means that
all kernel and initrd paths are relative to /, e.g.
root hd0,0
kernel /boot/vmlinuz-version ro root /dev/sdal
initrd /boot/initrd-version.img
boot /dev/sda
default 0
timeout 10
splashimage hd0,2 /grub/splash.xpm.gz
title Red Hat Linux Advanced Server 2.4.9-e.3smp
root hd0,0
kernel /boot/vmlinuz-2.4.9-e.3smp ro root /dev/sda1 hda ide-scsi console tty0 console ttyS0,19200
initrd /boot/initrd-2.4.9-e.3smp.img
title Red Hat Linux Advanced Server-up 2.4.9-e.3
root hd0,00
kernel /boot/vmlinuz-2.4.9-e.3 ro root /dev/sda1 s
initrd /boot/initrd-2.4.9-e.3.im
Additional information for editing the grub.conf:
You may need to disable GRUB s graphical interface and use the text-based
interface instead; otherwise, the GRUB screen will not be displayed in
BMU console redirection. To do so, comment out the line starting with
splashimage.
If you have multiple options in GRUB and you want all of them to start a
console session through the BMU serial connection, add
console
ttyS1,19200 to all options. The preceding example shows
ttyS0,19200 added to only the first option.
Enabling Login to the Console After Boot
Edit the file /etc/inittab, as follows:
Add a new line to configure a getty on the COM1 serial port:
co:2345:respawn:/sbin/agetty -h -L 19200 ttyS0 vt100
See the sample file, which shows the addition of the new line.
Table D-2. Sample File: /etc/innitab
inittab This file describes how the INIT process should set up
the system in a certain run-level.
Author: Miquel van Smoorenburg, miquels drinkel.nl.mugnet.org
Modified for RHS Linux by Marc Ewing and Donnie Barnes
Default runlevel. The runlevels used by RHS are:
0 - halt Do NOT set initdefault to this
1 - Single user mode
2 - Multiuser, without NFS The same as 3, if you do not have
networking
3 - Full multiuser mode
4 - unused
5 - X11
6 - reboot Do NOT set initdefault to this
id:3:initdefault:
System initialization.
si::sysinit:/etc/rc.d/rc.sysinit
l0:0:wait:/etc/rc.d/rc 0
l1:1:wait:/etc/rc.d/rc 1
l2:2:wait:/etc/rc.d/rc 2
l3:3:wait:/etc/rc.d/rc 3
l4:4:wait:/etc/rc.d/rc 4
l5:5:wait:/etc/rc.d/rc 5
l6:6:wait:/etc/rc.d/rc 6
Things to run in every runlevel.
ud::once:/sbin/update
Trap CTRL-ALT-DELETE
ca::ctrlaltdel:/sbin/shutdown -t3 -r now
When our UPS tells us power has failed, assume we have a few
minutes of power left. Schedule a shutdown for 2 minutes from now.
This does, of course, assume you have power installed and your
UPS is connected and working correctly.
pf::powerfail:/sbin/shutdown -f -h 2 Power Failure; System Shutting Down
If power was restored before the shutdown kicked in, cancel it.
pr:12345:powerokwait:/sbin/shutdown -c Power Restored; Shutdown Cancelled
Run gettys in standard runlevels
45:respawn:/sbin/mingetty tty1
45:respawn:/sbin/mingetty tty2
45:respawn:/sbin/mingetty tty3
45:respawn:/sbin/mingetty tty4
45:respawn:/sbin/mingetty tty5
45:respawn:/sbin/mingetty tty6
Run xdm in runlevel 5
xdm is now a separate service
x:5:respawn:/etc/X11/prefdm -nodaemon
Edit the file /etc/securetty, as follows:
Add a new line, with the name of the serial tty for COM1:
ttyS0
Table D-3. Sample File: /etc/securetty
vc/1
vc/2
vc/3
vc/4
vc/5
vc/6
vc/7
vc/8
vc/9
vc/10
vc/11
tty1
tty2
tty3
tty4
tty5
tty6
tty7
tty8
tty9
tty10
tty11
ttyS0
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