ATTO Technology 2500C operation manual Ndmp configuration provides backup, How Ndmp works

Page 20

2.2 NDMP configuration provides backup

NDMP (Network Data Management Protocol) provides backup for network-attached storage (NAS) devices. NAS devices are dedicated file servers and cannot host applications such as backup software. NDMP defines a common agent to interface between any NAS device and any backup software program, minimizing demand on network resources, and enabling local backups and disaster recovery.

Note

For NDMP-configured iPBridge 2500 models only

The ATTO iPBridge 2500, using the NDMP Version 4 Protocol Specification, 10/2001, (- skardal-ndmp4.03.doc), allows you to back up critical data locally using any combination of network-attached servers, backup devices and management applications from a central control, without taxing network traffic, by separating the data path and the control path.

How NDMP works

The NDMP protocol allows data backup and restoration over telnet networks using file-level commands, rather than block-level IO instructions.

The typical NDMP setup includes

a Data Service (usually disks)

a Tape Service

a client in control of the backup process called a Data Management Application (DMA).

The DMA controls the NDMP session. There is a master-slave relationship between the DMA and the data/tape servers. The iPBridge 2500 implements the Tape Service, along with a SCSI Service, to provide access to media changer devices.

The iPBridge 2500 platform provides several different types of management capability, including telnet/FTP through the two GigE data ports and an Ethernet 10/100/1000 management port which may be used as a data port in the iPBridge 2500 iSCSI-configured model, serial CLI management, and standard bridge hardware health checking.

A typical NDMP application involves a drive array, a host computer and a tape library. the host

11

computer may be attached to the disk and tape drives by any of several methods/technologies. The iPBridge uses Ethernet and Internet protocols.

The following example describes a host, Ethernet, tape library configuration.

1The DMA sends messages to the tape library’s SCSI Server to pick the appropriate cartridge and load it in the tape drive.

2The DMA sends commands to the tape drive to position the tape and configure the tape for writing (block size, etc.).

3The DMA opens a connection to the Data Server to exchange backup information.

4The DMA commands the Tape Server to prepare to receive data.

5The Tape Server responds with addressing information.

6The DMA passes the address to the Data server.

7The Data Server and Tape Server send data directly to each other.

8Metadata generated by the DMA is written to tape to indicate the end of files, directories, path names, etc., passed through to the tape server between backup data transfers.

NDMP uses a windowing mechanism in which the Tape Server writes a portion of the data, then pauses and waits for the DMA to take charge. The DMA may start a new window or write some Metadata.

The DMA may also move the tape while the transfer is paused. Once the DMA has finished with the Metadata, a new window is established and the transfer from the Data Server to the Tape Server continues.

The Data Server has no notification of the Tape Server being paused, so it must rely on the TCP stack to queue up data transferred during the pause time, and to implement flow control when queues are full.

ATTO Technology Inc. iPBridge Installation and Operation Manual

Image 20
Contents Atto iPBridgeTM 2500C/R/D Page Page Contents Additional configurations Copying iPBridge configurationsTroubleshooting Atto ExpressNAV interfaceAlternative interface options Maintenance commandsDiagnostic commands Ethernet commands Scsi configuration commandsSerial port configuration commands Ndmp commands ISCSI commandsMapping commands Appendix a Atto iPBridge, FibreBridge familyPage Intelligent Bridging Architecture, the engine IPBridge2500 featuresIPBridge 2500 provide storage options Possible storage Configurations Connectivity, infrastructure solutionsAtto iPBridge 2500R/D Installation instructions LED indicatorsExhibit 1.1-1 Atto iPBridge 2500R/D connector side Serial interfaceBack connector side Height of tallest component .535 inches Operating Temperature 0-70C externalAtto iPBridge 2500C Exhibit 1.2-1 Atto iPBridge 2500C faceplate Exhibit 1.2-2 Atto iPBridge 2500C board layout Configuring the iPBridge Microsoft iSCSI Initiator changesGetting an IP address Click Launch BrowserNdmp configuration provides backup How Ndmp worksAssign Ndmp names to devices Setting up NdmpProcedure Mapping devices Ndmp Map devices automaticallyMap devices manually Click AutoMapConfiguration mapping Ndmp Node names Single Target modeMapping devices iSCSI Multiple Target mode Automatically configure Multiple Target modeManually configure Multiple Target mode Click on the Multi Target Mode enabled button Click SubmitMapping single vs. multi target mode Exhibit 2.4-1 Examples of single and multiple target modesExhibit 2.4-2 Mapping with Atto ExpressNAV Additional configurations Change the current user name, passwordCreate a read only password or user name Set the Real Time ClockConfiguring Scsi devices Snmp protocolAccessing ExpressNAV Atto ExpressNAV interfaceBrowser compatibility To optimize ExpressNAV in Internet ExplorerExhibit 3.0-1 An ExpressNAV ExpressNAV pages Help FirmwareRestart Using Atto ExpressNAV Using FTP over GbEUpdating firmware Preliminary stepsCopying iPBridge configurations Using ZModem over the serial portZModem send clone.cln Send File/ZModem sendTroubleshooting Inside out methodCheck the host event log Check the iPBridge event and trace logsCheck for problems on attached devices Check host versionsComponent check Checking Scsi devicesChecking the iPBridge internal configuration Checking the serial portChecking iPBridge Ethernet ports Checking the LAN/WANChecking the iSCSI Host Adapter or NIC Checking the iSCSI OS driverChecking the Operating System Checking the applicationsChecking Ethernet Host Adapter or NIC Performance issuesChecking iPBridge Scsi ports Checking the host system Alternative interface options Use the serial port or headerUse Telnet Type iPBridge in the New Connection dialog boxExhibit 7.0-1 Start up messages AttoCommand conventions Symbol Indicates CLI provides ASCII-based interfaceCLI commands summary Command Defaults ExampleSntp 38 CLI General use commands Username VerboseModeMaintenance commands SpeedWriteDefault SNTPServerSpeedWrite TimeDiagnostic commands DumpEventLog DumpTraceLogEventLog EventLogFilterPing RouteDisplaySCSIPortList SCSITargetsTemperature SNMPTrapAddressSNMPTraps TailEventLogScsi configuration commands Performance enhancement to newly-mapped Scsi devices VirtualDriveResponseSerialPortEcho Serial port configuration commandsSerialPortBaudRate 50 CLI Ethernet commands 52 CLI Ndmp commands NDMPAuthTypeNDMPMaxVersion NDMPPortNumber54 CLI ISCSI commands MultiTargetMode ISNSLoginControlISNSServer Route Mapping commandsAutoMap List to the map which satisfies a search for the given LUN IPBridge products Product features 2500C/R/D 2700C/R/D 1500E/D 1550E/DAppendix a Atto iPBridge, FibreBridge family Fibre Bridge products Appendix B Cabling Scsi cablingCable types ExamplesEthernet connections Appendix C Glossary Term DefinitionVi Appendix Appendix D Safety standards and compliances FCC Standards Radio and Television InterferenceEuropean Standards Appendix E Atto accessories Appendix F Warranty, contact information Contact Atto Technology, Inc