Although Oracle Unbreakable Enterprise Kernel 3 (UEK3) supports the crashkernel=auto boot parameter, this option is not supported by the Xen hypervisor that is used for Oracle VM Server. Attempting to set this parameter results in the following boot errors:

(XEN) crashkernel: memory value expected
(XEN) Command line: console=com2,vga com2=57600,8n1 dom0_mem=840M allowsuperpage  
crashkernel=auto 

Dom0 fails to load the kdump service at start-up with the following message:

kdump: No crashkernel parameter specified for running kernel

Workaround: Specify a valid fixed memory range suitable for the server hardware if you choose to use this parameter. For example, crashkernel=256M@64M.

Bug 18174580