The software described in this documentation is either in Extended Support or Sustaining Support. See https://www.oracle.com/us/support/library/enterprise-linux-support-policies-069172.pdf for more information.
Oracle recommends that you upgrade the software described by this documentation as soon as possible.

2.2.25 Oracle VM 3.0 Guests Crash During Oracle Database Installation

PVHVM guests on Oracle VM 3.0 crash during Oracle Database installation if the value of the maximum memory (maxmem) parameter set for the guest is greater than the amount specified at boot time (memory). To avoid this issue, ensure that the values of the maxmem and memory parameters are the same. This issue has been resolved in Oracle VM 3.1.1. (Bug ID 13396734, 13970935)