Administrator Guide

Table Of Contents
Performance and Monitoring
This chapter describes RPO/RTO and the procedures to create and operate performance monitors.
Topics:
About performance
About performance monitoring
Monitor performance using the CLI
Port Monitoring
Statistics
Statistics tables
About performance
This chapter describes the following topics related to performance on metro node systems:
Configuration - Modifiable parameters to maximize performance and to manage Recovery Point Objective (RPO) and
Recovery Time Objective (RTO).
Monitoring - Tools and techniques to monitor the performance of metro node, and to identify and diagnose problems.
RPO and RTO
Recovery Point Objective (RPO): RPO is the time interval between the point of failure of a storage system and the expected
point in the past to which the storage system is capable of recovering customer data.
RPO is a maximum amount of data loss that can be tolerated by the application after a failure. The value of the RPO is highly
dependent upon the recovery technique used. For example, RPO for backups is typically days; for asynchronous replication
minutes; and for mirroring or synchronous replication seconds or instantaneous.
Recovery Time Objective (RTO): RTO is the time duration within which a storage solution is expected to recover from failure
and begin servicing application requests.
RTO is the longest tolerable application outage due to a failure of a storage system. RTO is a function of the storage
technology. It may measure in hours for backup systems, minutes for a remote replication, and seconds (or less) for a mirroring.
About performance monitoring
Performance monitors collect and displays statistics to determine how a port or volume is being used, how much I/O is being
processed, CPU usage, and so on.
Performance monitoring is supported in both the metro node CLI and Unisphere, and falls into three general types:
Current load monitoring allows administrators to watch CPU load during upgrades, I/O load across the inter-cluster WAN
link, and front-end compared to back-end load during data mining or back up.
Current load monitoring is supported in Unisphere.
Long term load monitoring collects data for capacity planning and load balancing.
Long term load monitoring is supported by monitors created in the CLI and/or perpetual monitors.
Troubleshooting monitoring helps identify bottlenecks and resource hogs.
Troubleshooting monitors are supported by monitors created in the CLI and/or perpetual monitors.
NOTE:
In Unisphere for metro node, performance statistics are displayed per cluster. To view statistics for both clusters in
a Metro configuration, connect to both clusters.
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