Uploaded November 2025 | Updated September 2026, 3 weeks ago
Per-Subvolume IO Metrics in CephFS - Igor Golikov & Alex Markuze, IBM
Understanding performance at a granular level is essential for debugging, optimization, and capacity planning in large-scale CephFS deployments. This session introduces a new mechanism for collecting and exposing per-subvolume IO metrics within the CephFS MDS. We’ll explore the design and implementation of subvolume-aware metrics tracking, including the use of labeled PerfCounters, latency histograms, and live throughput sampling. Attendees will learn how metrics are aggregated in the MDS, summarized at rank 0, and surfaced via the MetricAggregator infrastructure. The session will also cover challenges in high-frequency data collection, trade-offs in throughput representation, and how these metrics integrate with existing observability tooling. Whether you're operating multi-tenant CephFS clusters or building performance dashboards, this talk offers practical insights into tracking IO behavior where it matters most: the subvolume.
Per-Subvolume IO Metrics in CephFS - Igor Golikov & Alex Markuze, IBM
Understanding performance at a granular level is essential for debugging, optimization, and capacity planning in large-scale CephFS deployments. This session introduces a new mechanism for collecting and exposing per-subvolume IO metrics within the CephFS MDS. We’ll explore the design and implementation of subvolume-aware metrics tracking, including the use of labeled PerfCounters, latency histograms, and live throughput sampling. Attendees will learn how metrics are aggregated in the MDS, summarized at rank 0, and surfaced via the MetricAggregator infrastructure. The session will also cover challenges in high-frequency data collection, trade-offs in throughput representation, and how these metrics integrate with existing observability tooling. Whether you're operating multi-tenant CephFS clusters or building performance dashboards, this talk offers practical insights into tracking IO behavior where it matters most: the subvolume.
