Users Guide

– Add an entry to /etc/sysctl.conf
– echo "1" > /proc/sys/kernel/sysrq
• When Pass all keystrokes to server is enabled, the magic SysRq keys are sent to the operating system
on the managed system. The key sequence behavior to reset the operating system, that is reboot
without un-mounting or sync, depends on whether the magic SysRq is enabled or disabled on the
management station:
– If SysRq is enabled on the management station, then <Ctrl+Alt+SysRq+b> or <Alt+SysRq+b>
resets the management station irrespective of the system’s state.
– If SysRq is disabled on the management station, then the <Ctrl+Alt+SysRq+b> or <Alt+SysRq
+b>keys resets the operating system on the managed system.
– Other SysRq key combinations (example, <Alt+SysRq+k>, <Ctrl+Alt+SysRq+m>, and so on) are
passed to the managed system irrespective of the SysRq keys enabled or not on the management
station.
Using SysRq magic keys through remote console
You can enable SysRq magic keys through the remote console using any of the following:
• Opensoure IPMI tool
• Using SSH/Telnet or External Serial Connector
Using opensource IPMI tool
Make sure that BIOS/iDRAC settings supports console redirection using SOL.
1. At the command prompt, run the SOL activate command:
Ipmitool –I lanplus –H <ipaddr> -U <username> -P <passwd> sol activate
The SOL session is activated.
2. After the server boots to the operating system, the localhost.localdomain login prompt appears.
Log in using the operating system user name and password.
3. If SysRq is not enabled, enable using echo 1 >/proc/sys/kernel/sysrq.
4. Run break sequence ~B.
5. Use the SysRq magic key to enable the SysRq function. For example, the following command
displays the memory information on the console:
echo m > /proc/sysrq-trigger displays
Using SSH/Telnet or external serial connector (directly connecting through serial cable)
1. For telnet/SSH sessions, after logging in using the iDRAC username and password, at the /admin>
prompt, run the command console com2. The localhost.localdomain prompt appears.
2. For console redirection using external serial connector directly connected to the system through a
serial cable, the localhost.localdomain login prompt appears after the server boots to the
operating system.
3. Log in using the operating system user name and password.
4. If SysRq is not enabled, enable using echo 1 >/proc/sys/kernel/sysrq.
5. Use the magic key to enable the SysRq function. For example, the following command reboots the
server:
echo b > /proc/sysrq-trigger
NOTE: You do not have to run break sequence before using the magic SysRq keys.
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