... ciscocm.version3-keys.cop.sgn 3. Use the following command to shut down CUCM: utils system shutdown 4. In this example the hardware was 2vCPU, 4096Mb vRAM, one 80Gb virtual disk. The following Guest VM Settings changes were required in order to upgrade to CUCM 11.5 (with 1000 users): https://www.cisco.com/c/dam/en/us/td/docs/voice_ip_comm/uc_system/virtual... a. Guest OS: switch to 64-bit Red Hat Enterprise Linux 6 b. vRAM settings: increase the RAM size to 6 Gb c. Configure the Network Adapter: - Take ...