Upgrade and Migration Guide for Cisco Unified Communications Manager and the IM and Presence Service, Release 15 and SUs - Change the Virtualization Software

Publisher

Cisco Systems

URL

https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/upgrade/15/cucm_b_upgrade-and-migration-guide_15/cucm_b_upgrade-migration-guide-1251su2_chapter_01000.html

Published

2026-08-14

Updated

unknown

Accessed

2026-09-25

HTTP status

200

License

Cisco website terms of use; no-redistribution; short excerpts and locators only

Source notes citing this source

• Expanding a Unified CM vDisk adds the space to the common partition on the next restart, but it does not increase the system's user capacity. in context
• The Release 15 guide's ESXi upgrade procedure has four steps: move the Unified CM VM off the host (vMotion, or power down and copy), upgrade ESXi per VMware's procedure, verify the upgrade, then return the VM to the host. in context
• Downloading a new OVA is optional when upgrading Unified CM 15: if the system already runs on a VM and its deployment size has not changed, no new OVA is needed. A new OVA is needed when the system size changes. in context
• To change a Unified CM VM's vCPU, vRAM or vDisk, the Release 15 upgrade guide says to take a DRS backup, shut down the VM, then edit the settings in the vSphere Client, updating the reservation value to match the new release's specifications. in context

Cite this source record

APA

WarmTransfer. (2026, August 14). Upgrade and Migration Guide for Cisco Unified Communications Manager and the IM and Presence Service, Release 15 and SUs - Change the Virtualization Software. WarmTransfer. https://warmtransfer.net/knowledge/sources/cisco-cucm15-upgrade-guide-virtualization

BibTeX

@misc{warmtransfer-cisco-cucm15-upgrade-guide-virtualization,
  title  = {Upgrade and Migration Guide for Cisco Unified Communications Manager and the IM and Presence Service, Release 15 and SUs - Change the Virtualization Software},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/sources/cisco-cucm15-upgrade-guide-virtualization},
  note   = {Cisco Systems, accessed 2026-09-25}
}