What is the key combination for triggering SysRq to force a manual crash of a Red Hat Enterprise Linux Guest running over VMware Hypervisor?
Environment
- All Red Hat Enterprise Releases
- VMware® Guest
Issue
- What key combination should be pressed in-order to panic the system manually using SysRq keys when running RHEL as a guest VM on VMware?
Resolution
The key sequence remains same for manually crashing RHEL guests running on VMware > [Alt + PrintScreen + c]
Above key sequence will only work if the Guest is running in text console. If the Guest VM is running with a GUI (e.g. Gnome or KDE session), switch to a text console before issuing the SysRq command.
What if RHEL guest is running in GUI mode and it is not possible to switch to Text console ?
- Use 'Vmware Vsphere web2.0 client' (Basically this is a IE browser based interface). This application maps the sysrq keys easily (for sysrq magic keys one can use a virtual key board as well).
OR
- In case of complete server hang it might not be possible to switch from GUI to TEXT console, In such case it is possible to extract vmcore from VM snaphot using vmss2core tool shipped by vmware. Please refer following article - How to capture a vmcore of hung Red Hat Enterprise Linux VMware® guest system using VMware® "vmss2core" tool ?
OR
- If the client is using Apple Mac's then to send the alt-sysrq-c combo to a VM from OSX is:
-
The F13 key on a Mac keyboard, sends the SYSRQ signal.
-
Pressing ALT-F13-c, it forces the machine to dump.
-
If the client doesn’t have a full blown keyboard, the combo can be sent using the keyboard viewer.
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