Storage performance monitoring tracks the IOPS, data throughput and latency of storage systems, together with their capacity, so that slow volumes and filling pools are found before applications are affected. This guide explains the key metrics and how XorMon, open source under GPL v3, collects and graphs them for NetApp, IBM, HPE, Lenovo, Dell EMC, Hitachi, Huawei and other vendors.
Last updated: November 11, 2026.
The key storage performance metrics are IOPS, throughput and latency, read together with capacity. IOPS counts the operations a storage system handles in one second, throughput is the amount of data it moves per unit of time, and latency is the time between a request and its response.
Two details matter in practice: For the same amount of data, the number of IOPS depends on the block size: a 1 MB file read in 4 kB blocks is 256 read operations. Throughput is often confused with bandwidth, which is the theoretical maximum of the channel. In XorMon, the Storage Overview report shows IOPS, data throughput and latency for the last day, week and month, next to capacity per pool.
Sources: Glossary, updated 2026-11-05, and Storage overview, updated 2026-11-06.
Capacity is tracked next to IOPS, throughput and latency because storage is one of the resources that capacity planning sizes. Capacity planning predicts the resources a workload needs to meet its performance targets, to avoid under-provisioning, which creates bottlenecks, and over-provisioning, which wastes cost.
XorMon reports capacity per pool in the Storage Overview. Detailed capacity monitoring, per storage total, pool and tier, with formatted, raw, replication, snapshot, virtual, deduplication, compressed and spare capacity, is available for IBM Storwize, SVC and FlashSystem, Lenovo V Series, Inspur AS5600, 5500, 2600 and 2200, Hitachi VSP and VSP-G, HPE XP7 and XP8, and HPE Primera and 3PAR. It uses smart trending graphs, and the Enhanced Predictions storage capacity table shows the days left until 90% and 100%.
Sources: Capacity planning glossary entry and Capacity monitoring, both updated 2026-11-05, Storage overview, updated 2026-11-06, and Enhanced Predictions, updated 2026-05-04.
XorMon reads performance and capacity data from each storage system through an interface that depends on the storage model, such as REST API, CLI, SNMP or SMI-S, then graphs it, reports on it and alerts on it. The data frequency table lists the sample rate and collection interval per technology.
Sources: Storage monitoring, updated 2026-11-11, Feature matrix, Installation, Data frequency, Heatmap and Health status, all three updated 2026-05-04, Storage overview, updated 2026-11-06, Storage Topology, updated 2026-10-07, and Alerting, updated 2026-10-13.
XorMon graphs performance and capacity metrics on storage arrays, NAS systems and backup storage, such as IO, data throughput and latency; the exact set of metrics depends on the storage model. It supports storage from NetApp, IBM, HPE, Lenovo, Dell EMC, Hitachi and Huawei, and from other vendors such as Everpure (Pure Storage), Fujitsu, Infinidat, Cohesity and Synology.
The full list of supported products is on the storage monitoring page, and Fibre Channel switches from Broadcom (Brocade), Cisco and QLogic are on the SAN monitoring page. For NAS, XorMon monitors QNAP through QNAP Q'center and Synology through SNMP, and the list also includes Hitachi HNAS and Huawei OceanStor Pacific NAS. For backup storage, it graphs capacity, IO, data and latency per pool for Cohesity DataProtect and Rubrik CDM, and capacity and data per server for ExaGrid Tiered Backup Storage; backup software is covered on the backup monitoring page.
Sources: Storage monitoring, updated 2026-11-11, SAN monitoring and Backup monitoring, both updated 2026-11-07, QNAP, Rubrik and ExaGrid, all three updated 2026-11-09, Cohesity, updated 2026-11-10, and Synology, updated 2026-11-11.
Storage performance monitoring tools generally fall into three categories: the tools of the array vendor, multi-vendor storage monitoring tools, and general infrastructure monitoring platforms that include storage. XorMon monitors storage from many vendors and, in the same platform, servers, virtualization, SAN, LAN, backup, tape, databases, cloud and containers.
The choice depends on how many storage vendors you run and whether storage should appear in the same view as the servers and the SAN that use it. XorMon is open source under the GNU GPL v3, free to download and run in production, with no registration and no time limit; the free edition is limited to 4 storage devices, and the Enterprise edition, which comes with a support contract, removes all device and feature limits. Named tools are compared on the infrastructure monitoring tools page.
Sources: About Xorux, Pricing (FAQ), Support and editions, and Top infrastructure monitoring tools in 2026, updated 2026-11-06.
IOPS counts the SCSI commands or NAS operations that a storage system handles in one second, while throughput is the amount of data moved per unit of time. The same amount of data gives a different number of IOPS depending on the block size: a 1 MB file read in 4 kB blocks is 256 read operations.
Storage latency is the time between a request or command being issued and its response, measured in seconds, milliseconds or microseconds. XorMon graphs latency per subsystem, such as pools and volumes, depending on the storage model, and its heatmap colors storage pools and volumes by their response time.
Yes. XorMon monitors QNAP NAS through QNAP Q'center and Synology NAS through SNMP, and its list of supported storage also includes Hitachi HNAS and Huawei OceanStor Pacific NAS. For QNAP, it graphs capacity, IO, data throughput, latency and block size per pool.
Yes. XorMon is open source under the GNU GPL v3 and free to download and run in production, with no registration and no time limit. The free edition monitors up to 4 storage devices, and the Enterprise edition, which comes with a support contract, removes all device and feature limits.