The common partition needs at least 25 GB free before upgrading. Cisco warns that an upgrade can still fail with an insufficient-space error even with 25 GB free.

Checked 2026-09-25

In some cases, even if 25GB of free space is available, upgrade may fail with the error message as insufficient space.
Vendor
Cisco
Product
Unified Communications Manager
Subsystem
disk space
Deployment
on-premises
Region
not restricted
Release range
Release 15 and SUs as of 2026-09-25
Checked
2026-09-25

Sources

Cite this note

APA

WarmTransfer. (2026, September 25). Planning a Unified CM upgrade: source note cucm-upgrade-planning-common-partition-25gb. WarmTransfer. https://warmtransfer.net/knowledge/claims/cucm-upgrade-planning-common-partition-25gb

BibTeX

@misc{warmtransfer-claim-cucm-upgrade-planning-common-partition-25gb,
  title  = {Planning a Unified CM upgrade: source note cucm-upgrade-planning-common-partition-25gb},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/cucm-upgrade-planning-common-partition-25gb},
  note   = {Source note cucm-upgrade-planning-common-partition-25gb, checked 2026-09-25}
}

Read in context