Cisco DCNM Fundamentals Overview
This chapter provides an overview of the basic Cisco DCNM-SAN components and includes the following sections:
DCNM-SAN Server is a platform for advanced MDS monitoring, troubleshooting, and configuration capabilities. DCNM-SAN Server provides centralized MDS management services and performance monitoring. SNMP operations are used to efficiently collect fabric information. The Cisco DCNM-SAN software, including the server components, requires about 60 MB of hard disk space on your workstation. Cisco DCNM-SAN Server runs on Windows 2000, Windows 2003, Windows 2008, Windows XP, Windows 7, Solaris 9 and 10, and Red Hat Enterprise Linux AS Release 5.
Each computer configured as a Cisco DCNM-SAN Server can monitor multiple Fibre Channel SAN fabrics. Up to 16 clients (by default) can connect to a single Cisco DCNM-SAN Server concurrently. The Cisco DCNM-SAN Clients can also connect directly to an MDS switch in fabrics that are not monitored by a Cisco DCNM-SAN Server, which ensures that you can manage any of your MDS devices from a single console.
Cisco DCNM-SAN Client is a Java and SNMP-based network fabric and device management tool with a GUI that displays real-time views of your network fabric, including Cisco Nexus 5000 Series switches, Cisco MDS 9000 Family switches and third-party switches, hosts, and storage devices.
DCNM-SAN Client provides Fibre Channel troubleshooting tools, in addition to complete configuration and status monitoring capabilities for Cisco MDS 9000 Family switches and Cisco Nexus 5000 Series switches. You can use these health and configuration analysis tools on the MDS 9000 Family switch or Cisco Nexus 5000 Series switch to perform Fibre Channel ping and traceroute.
Fabric Manager Release 4.1(1b) and later releases provide a multilevel security system by adding a server admin role that allows access to limited features. The configuration capabilities of a server admin is limited to configuring FlexAttach and relevant data. Advanced mode option is available only for network administrators and provides all of the DCNM-SAN features, including security, IVR, iSCSI, and FICON.
Device Manager provides a graphical representation of a Cisco MDS 9000 Family switch chassis, Cisco Nexus 5000 Series switch chassis, or Cisco Nexus 7000 Series switch chassis (FCoE only) along with the installed switching modules, the supervisor modules, the status of each port within each module, the power supplies, and the fan assemblies.
The tables in the DCNM-SAN Information pane basically correspond to the dialog boxes that appear in Device Manager. However, while DCNM-SAN tables show values for one or more switches, a Device Manager dialog box shows values for a single switch. Device Manager also provides more detailed information for verifying or troubleshooting device-specific configuration than DCNM-SAN.
Device Manager provides two views: Device View and Summary View. Use Summary View to monitor interfaces on the switch. Use Device View to perform switch-level configurations including the following configurations:
- Configuring virtual Fibre Channel interfaces
- Configuring Fibre Channel over Ethernet (FCoE) features
- Configuring zones for multiple VSANs
- Managing ports, PortChannels, and trunking
- Managing SNMPv3 security access to switches
- Managing CLI security access to the switch
- Managing alarms, events, and notifications
- Saving and copying configuration files and software image
- Viewing hardware configuration
- Viewing chassis, module, port status, and statistics
DCNM-SAN Web Client
With DCNM-SAN Web Client you can monitor Cisco MDS switch events, performance, and inventory from a remote location using a web browser.
- Performance Manager Summary reports—The Performance Manager summary report provides a high-level view of your network performance. These reports list the average and peak throughput and provides hot-links to additional performance graphs and tables with additional statistics. Both tabular and graphical reports are available for all interconnections monitored by Performance Manager.
- Performance Manager drill-down reports—Performance Manager can analyze daily, weekly, monthly and yearly trends. You can also view the results for specific time intervals using the interactive zooming functionality. These reports are only available if you create a collection using Performance Manager and start the collector.
- Zero maintenance database for statistics storage—No maintenance is required to maintain Performance Manager’s round-robin database, because its size does not increase over time. At prescribed intervals the oldest samples are averaged (rolled-up) and saved. A full two days of raw samples are saved for maximum resolution. Gradually the resolution is reduced as groups of the oldest samples are rolled up together.
The primary purpose of DCNM-SAN is to manage the network. A key management capability is network performance monitoring. Performance Manager gathers network device statistics historically and provides this information graphically using a web browser. Performance Manager presents recent statistics in detail and older statistics in summary. Performance Manager also integrates with external tools such as Cisco Traffic Analyzer.
Performance Manager has three operational stages:
- Definition—The Flow Wizard sets up flows in the switches.
- Collection—The Web Server Performance Collection screen collects information on desired fabrics.
- Presentation—Generates web pages to present the collected data through DCNM-SAN Web Server.
Performance Manager can collect statistics for ISLs, hosts, storage elements, and configured flows. Flows are defined based on a host-to-storage (or storage-to-host) link. Performance Manager gathers statistics from across the fabric based on collection configuration files. These files determine which SAN elements and SAN links Performance Manager gathers statistics for. Based on this configuration, Performance Manager communicates with the appropriate devices (switches, hosts, or storage elements) and collects the appropriate information at fixed five-minute intervals.
Authentication in DCNM-SAN Client
Administrators launch DCNM-SAN Client and select the seed switch that is used to discover the fabric. The user name and password are passed to DCNM-SAN Server and are used to authenticate to the seed switch. If this user name and password are not a recognized SNMP user name and password, either DCNM-SAN Client or DCNM-SAN Server opens a CLI session to the switch (SSH or Telnet) and retries the user name and password pair. If the user name and password are recognized by the switch in either the local switch authentication database or through a remote AAA server, then the switch creates a temporary SNMP user name that is used by DCNM-SAN Client and DCNM-SAN Server.
Cisco Traffic Analyzer
Cisco Traffic Analyzer provides real-time analysis of SPAN traffic or analysis of captured traffic through a Web browser user interface. Traffic encapsulated by one or more Port Analyzer Adapter products can be analyzed concurrently with a single workstation running Cisco Traffic Analyzer, which is based on ntop, a public domain software enhanced by Cisco for Fibre Channel traffic analysis.
Cisco Traffic Analyzer monitors round-trip response times, SCSI I/Os per second, SCSI read or traffic throughput and frame counts, SCSI session status, and management task information. Additional statistics are also available on Fibre Channel frame sizes and network management protocols.
DCNM-SAN provides extensive SAN discovery, topology mapping, and information viewing capabilities. DCNM-SAN collects information on the fabric topology through SNMP queries to the switches connected to it. DCNM-SAN recreates a fabric topology, presents it in a customizable map, and provides inventory and configuration information in multiple viewing options such as fabric view, device view, summary view, and operation view.
Once DCNM-SAN is invoked, a SAN discovery process begins. Using information polled from a seed Cisco MDS 9000 Family switch, including Name Server registrations, Fibre Channel Generic Services (FC-GS), Fabric Shortest Path First (FSPF), and SCSI-3, DCNM-SAN automatically discovers all devices and interconnects on one or more fabrics. All available switches, host bus adapters (HBAs), and storage devices are discovered. The Cisco MDS 9000 Family switches use Fabric-Device Management Interface (FMDI) to retrieve the HBA model, serial number and firmware version, and host operating-system type and version discovery without host agents. DCNM-SAN gathers this information through SNMP queries to each switch. The device information discovered includes device names, software revision levels, vendor, ISLs, PortChannels, and VSANs.
DCNM-SAN and Device Manager provide multiple tools for monitoring the performance of the overall fabric, SAN elements, and SAN links. These tools provide real-time statistics as well as historical performance monitoring.
Real-time performance statistics are a useful tool in dynamic troubleshooting and fault isolation within the fabric. Real-time statistics gather data on parts of the fabric in user-configurable intervals and display these results in DCNM-SAN and Device Manager.
Device Manager provides an easy tool for monitoring ports on the Cisco MDS 9000 Family switches. This tool gathers statistics at a configurable interval and displays the results in tables or charts. These statistics show the performance of the selected port in real-time and can be used for performance monitoring and troubleshooting. For a selected port, you can monitor any of a number of statistics including traffic in and out, errors, class 2 traffic, and FICON data. You can set the polling interval from ten seconds to one hour, and display the results based on a number of selectable options including absolute value, value per second, and minimum or maximum value per second.