In Cisco's UCS common-problems technote, high CPU from I/O wait that restarted the CCM and CTI services was attributed to the UCS platform and its storage, and isolating it needed UCS logs.
Checked 2026-10-02
I/O WAIT is usually an issue with the UCS platform and its storage.
- Vendor
- Cisco
- Product
- Cisco Unified Communications Manager
- Subsystem
- platform I/O
- Deployment
- on-premises
- Region
- not restricted
- Release range
- not stated; UCS deployments, technote dated 2015
- Checked
- 2026-10-02
Sources
- CUCM Common Problems on UCS Platform: Core, High CPU - I/O, Hung State — Cisco Systems · tier 2 current vendor documentation · Scenario 1: High CPU Utilization Due to I/O Wait Issue > Resolution
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting high CPU and service crashes in Unified CM: source note cucm-high-cpu-troubleshooting-ucs-iowait-storage-cause. WarmTransfer. https://warmtransfer.net/knowledge/claims/cucm-high-cpu-troubleshooting-ucs-iowait-storage-cause
BibTeX
@misc{warmtransfer-claim-cucm-high-cpu-troubleshooting-ucs-iowait-storage-cause,
title = {Troubleshooting high CPU and service crashes in Unified CM: source note cucm-high-cpu-troubleshooting-ucs-iowait-storage-cause},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/cucm-high-cpu-troubleshooting-ucs-iowait-storage-cause},
note = {Source note cucm-high-cpu-troubleshooting-ucs-iowait-storage-cause, checked 2026-10-02}
}