ATTO Technology 2700C Checking the Ethernet host adapter or NIC, Checking applications

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3Verify that packets are not being dropped along the LAN/WAN. Many utilities track packet activity and switch statistics.

Checking the Ethernet host adapter or NIC

Ethernet storage adapters generally outperform accelerated NICs and un-accelerated NICs by offloading most of the processing from the host.

An accelerated NIC provides some offloading, but still requires a host OS iSCSI driver, making the host spend more CPU cycles.

An un-accelerated NIC does not offload anything so the CPU must do much of the processing.

1Verify that the adapter or NIC is sent to auto- negotiate or forced to 1000 Mbs.

2Set the MTU size to the largest MTU size supported in the LAN/WAN using the Ethernet page in the ATTO ExpressNAV interface.

9k frame size is the current optimized frame size for the iPBridge. Smaller frame sizes cause a decrease in performance. Many switch and router vendors do not support the larger frame size of 9k or 16k.

3Set the maximum transfer size to the most efficient size for the intended target(s). For many tape drives, 64k is the optimal setting.

Checking applications

Some applications can be configured to change transfer sizes. Configure the application for the optimal size for the particular device(s) connected to the iPBridge.

Checking the host system

The faster the host, the faster your transfer times will be. The work flow goes only as fast as the slowest connection in the host system, so transferring data from an IDE drive, 100Mb connection, a DLT 4000, a high speed RAID volume across the country, or other

applications, slows the system no matter how fast everything else is in the system.

1Verify that the iSCSI storage adapter or NIC is connected to the fastest PCI bus connector supported by the adapter or NIC.

If the adapter supports PCI-X, place the adapter in a PCI-X slot. If one is not available, the host might not achieve the optimal performance capable from the adapter.

Even placing a PCI-X adapter into a 64 bit 66 MHz slot loses performance. Some adapters adjust clock speed depending on the speed of the PCI slot into which they are plugged.

2The host OS disk and swap disk/partition/file should be on a high speed drive to minimize the time needed to access the host’s virtual memory.

The more memory a system has, the less time it spends accessing virtual memory (hard drive space).

Checking the Operating System

If possible, eliminate swap space and virtual drives which require large amounts of system memory. However, the OS might not allow the elimination of swap space. An OS set to run many kinds of different servers spends much of its CPU cycles on other operations, thus slowing down performance.

Optimizing ATTO ExpressNAV in Internet Explorer

1Go to the browser toolbar and select Tools

2Select Internet Options

3Select the Security tab

4Select the Custom Level button.

5On the menu presented, go to the Microsoft VM, Java permissions and make sure Disable Java is not selected.

6Go to the Miscellaneous topic and select

METAREFRESH.

30 Troubleshooting

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Contents Atto Technology, Inc Atto iPBridge 2700C/R/DPage Page Contents Alternative interface options TroubleshootingAtto ExpressNAV pages Updating firmwareCLI commands summary General use commands Maintenance commandsDiagnostic commands ISCSI commands Serial port configuration commandsFibre Channel configuration commands Ethernet commandsMapping commands Appendix a Atto iPBridge, FibreBridge familyAppendix B Cabling Iii Page Gigabit Ethernet GbE a transmission Atto iPBridge 2700 features, benefitsEmbedded software features Atto iPBridge 2700 provides storage optionsScsi Possible storage ConfigurationsAtto iPBridge 2700R/D Installation instructions Front label side Back connector sideInstallation Atto iPBridge 2700R/D Serial management header Atto iPBridge 2700CEthernet interface Fibre Channel interfaceFaceplate side Power side Configuring the iPBridge Click Launch Browser Getting an IP addressMap devices automatically Default target nodeTarget management Target namesMultiple target nodes Automatically configure multiple targetsManually configure multiple target nodes Chap to control access different ChapPhysical connections Initiator/Host to Network Mapping default vs. multiple target nodesInstallation mapping Page Installation mapping Click Time & Date Additional configurationsCreate a read only password or username Set the Real Time ClockSnmp protocol Set up a Vlan Virtual Local Area NetworkAtto ExpressNAV interface Browser compatibilityOpen an ExpressNAV session Exhibit 3.0-1 An ExpressNAV Atto ExpressNAV pages Manual Target Management iSCSI Target Management Bridge ConfigurationFirmware Update Advanced CLI ConfigurationPreliminary steps Using Atto ExpressNAVUsing FTP over GbE Updating firmwareFirmware update Check the event and trace logs TroubleshootingInside out method Check the Host Event LogExhibit 5.0-1 iPBridge 2700C faceplate Check for problems on attached devicesCheck iPBridge product versions and update firmware Check host versionsCheck components Checking the iSCSI Host Adapter or NIC Checking the LAN/WANChecking the iPBridge Ethernet ports Performance IssuesChecking the iSCSI OS driver Checking the Operating SystemOptimizing Atto ExpressNAV in Internet Explorer Checking the Ethernet host adapter or NICChecking applications Checking the host systemType iPBridge in the New Connection dialog box Alternative interface optionsUse the serial port or header Use TelnetExhibit 6.0-1 Start up messages Ready Command conventions Symbol IndicatesFCTargets command CLI provides ASCII-based interfaceCLI Error Messages Command Defaults Example CLI commands summaryRmon Sntp Alternative interfaces CLI General use commands VerboseMode UsernameMaintenance commands TailEventLog SpeedWriteDefaultSNTPServer SpeedWriteDiagnostic commands EmailNotify DumpEventLogDumpTraceLog EmailFromAddressSerialNumber IsReservedPing RouteDisplayTraceLogFilter TemperatureSNMPTraps TraceLogSerial port configuration commands SerialPortBaudRateSerialPortEcho Fibre Channel configuration commands Ethernet commands ReadOnlyUsername ReadOnlyPasswordISCSI commands ISNSLoginControl ISCSIWANIPAddressISNSServer Mapping commands Route Product features Appendix a Atto FibreBridge familyAtto iPBridge Atto FibreBridge Cable length Cable size Appendix a CablingFibre Channel connections Ethernet connectionsTerm Definition Appendix B GlossaryFCC Standards Radio and Television Interference Appendix C Safety standards and compliancesVi Appendix Appendix D Atto accessories Contact Atto Technology, Inc Appendix E Warranty, contact information
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