I/O pressure sustained
PSI reports I/O contention with corroborating disk-latency or error signal. Catches the modern-NVMe case where iowait stays at zero but the CPU is briefly blocking on I/O often enough to matter. Not available on stock RHEL-family kernels (PSI ships disabled there; enable with the psi=1 boot parameter).
Remediation
When this rule fires on one of your servers, the dashboard alert detail page renders the full remediation guidance: the command to run, what to verify after, and Furnace's annotation for your specific distro + hardware. Sign in at app.glassmkr.com to see the live alert.