In RTMT, %IOWait is the percentage of time the CPU was idle while waiting for an outstanding disk I/O request, distinct from %User (application level) and %System (kernel level) utilisation.
Checked 2026-10-02
percentage of time that the CPU was idle as it waited for an outstanding disk I/O request
- Vendor
- Cisco
- Product
- Cisco Unified Communications Manager
- Subsystem
- RTMT counters
- Deployment
- on-premises
- Region
- not restricted
- Release range
- 6.0 per source
- Checked
- 2026-10-02
Sources
- Monitoring and Troubleshooting Cisco Unified Communications Manager 6.0 High CPU, using Real Time Monitoring Tool (RTMT) — Cisco Systems (TAC) · tier 2 current vendor documentation · RTMT CPU and Memory page counter definitions
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting high CPU and service crashes in Unified CM: source note cucm-high-cpu-troubleshooting-rtmt-cpu-iowait-definition. WarmTransfer. https://warmtransfer.net/knowledge/claims/cucm-high-cpu-troubleshooting-rtmt-cpu-iowait-definition
BibTeX
@misc{warmtransfer-claim-cucm-high-cpu-troubleshooting-rtmt-cpu-iowait-definition,
title = {Troubleshooting high CPU and service crashes in Unified CM: source note cucm-high-cpu-troubleshooting-rtmt-cpu-iowait-definition},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/cucm-high-cpu-troubleshooting-rtmt-cpu-iowait-definition},
note = {Source note cucm-high-cpu-troubleshooting-rtmt-cpu-iowait-definition, checked 2026-10-02}
}