Bootable Ucsinstall Ucos Unrst 8.6.2.10000-14.sgn.161

It is a fundamental rule to always upgrade the publisher and any standalone TFTP servers first, followed by the remaining subscriber nodes in a specific sequence to minimize call-processing interruptions.

| Component | Minimum Requirement | Notes | |-----------|---------------------|-------| | | 4 GB | Earlier versions required 2 GB; 8.6.x requires 4 GB for proper operation. Insufficient RAM can lead to performance degradation and installation failures. | | Disk Space | 146 GB | A 72 GB disk is no longer sufficient. Consider future growth and upgrade paths when provisioning storage. | | CPU | 2 vCPUs | Modern installations benefit from additional vCPUs for improved processing capacity. | | Network | VMXNET3 (for VMware) | Using the VMXNET3 paravirtualized network adapter provides better performance and lower CPU utilization compared to the default E1000. | | Virtualization | VMware ESXi | While CUCM can run on VMware, official support is for Cisco-tested hardware. Lab environments are less stringent. | Bootable UCSInstall UCOS UNRST 8.6.2.10000-14.sgn.161

If you are upgrading from 8.5(x) or earlier, you must install the ciscocm.refresh_upgrade_v1.1.cop.sgn patch before starting the upgrade process. It is a fundamental rule to always upgrade