hplto-5tapelibraries …h20628. · hplto-5tapelibraries usingdatapathfailoverandcontrolpath...

HP LTO-5 Tape LibrariesUsing Data Path Failover and Control PathFailover

HP Part Number: AK378-96050Published: October 2011Edition: Second

Contents1 Overview..................................................................................................5

HP LTO-5 data path port failover overview...................................................................................5HP LTO-5 control path failover overview.......................................................................................6

2 Technology for drive-assisted failover.............................................................8Technology for data path port failover.........................................................................................8Technology for control path failover.............................................................................................8

Traditional bridged library control path...................................................................................8Virtual library connection using NPIV...................................................................................10

3 Configuring failover for the ESL G3 Tape Library...........................................14Configuring data path failover..................................................................................................14

Enabling data path failover.................................................................................................14Verifying data path failover.................................................................................................14Diagnosing data path failover.............................................................................................15Disabling data path failover................................................................................................15

Configuring control path failover...............................................................................................15Enabling control path port failover on the library....................................................................16Configuration requirements after enabling control path failure..................................................16

Library configuration......................................................................................................16SAN configuration........................................................................................................16

Verifying control path failover..............................................................................................17Disabling control path failover.............................................................................................17

4 Configuring failover for the MSL Tape Libraries.............................................19Configuring data path port failover...........................................................................................19

Enabling data path port failover..........................................................................................19Verifying data path port failover..........................................................................................20

Configuring control path failover...............................................................................................20Enabling control path port failover on the library....................................................................20Configuration requirements after enabling control path failure..................................................22Verifying control path failover..............................................................................................23Hardware-specific requirements...........................................................................................23

Brocade switches..........................................................................................................23Cisco switches..............................................................................................................24

5 Backup application test results for MSL Tape Libraries....................................25Test descriptions.....................................................................................................................25

DPF test 1 — Broken link.....................................................................................................25DPF test 2— Disabled port..................................................................................................25CPF test 1 — Normal: failed drive removal............................................................................25CPF test 2 — Normal: install new drive.................................................................................25CPF test 3 — Error: disable active drive and cause failover......................................................26

HP Data Protector on Microsoft Windows...................................................................................26HP Data Protector on Red Hat Linux..........................................................................................27HP Data Protector on HP-UX 11iv3.............................................................................................27Symantec Backup Exec............................................................................................................28Symantec NetBackup..............................................................................................................29

6 Backup application test results for ESL G3 Tape Libraries................................31Test descriptions.....................................................................................................................31

DPF test 1 — Data path failover during backup......................................................................31DPF test 2— Data path failover during restore........................................................................31

Contents 3

CPF test 1 — Control path failover during backups running on control path and non-control pathdrives...............................................................................................................................31

HP Data Protector...................................................................................................................31IBM TSM...............................................................................................................................32EMC Networker.....................................................................................................................34Symantec Backup Exec............................................................................................................35CommVault Simpana..............................................................................................................36CA ARCserve.........................................................................................................................36

7 Support and other resources......................................................................38HP technical support...............................................................................................................38HP websites...........................................................................................................................38Typographic conventions.........................................................................................................38Subscription service................................................................................................................39HP-authorized reseller..............................................................................................................39

4 Contents

1 OverviewWith today’s high dependency on access to business information, safe guarded data and limitedbackup windows, the reliability of the backup hardware and software is vital. Additionally backupoperations are usually automated, often done at night, and any first pass operator intervention isdone remotely. To assist with these enterprise demands, Hewlett-Packard has introduced tworeliability enhancements to its new ESL G3 tape libraries and to the MSL2024, MSL4048, MSL8048,and MSL8096 Tape Libraries with LTO-5 Fibre Channel tape drives.

• Data path port failover where a standby path is configured for the data path to the tape driveand activated following link failures

• Library control path port failover where a second drive is configured to host a standby librarycontrol path that can be activated following link failures.

Failover functionality in the HP LTO-5 tape drives and HP LTO tape libraries transfers the activepath and all settings to the standby path following failures.Control path failover and data path port failover are not supported on the MSL6000 Tape Libraries.

HP LTO-5 data path port failover overviewData path port failover (see Figure 1 (page 6)) may be configured on each dual-port Fibre Channeltape drive in the library. When data path port failover is configured one link is active and is theprimary data path. The second link is a standby data path. The drive will verify that the secondlink is able to receive a Fibre Channel signal and complete speed negotiation but the drive willnot log into the SAN using the standby link.The drive monitors the links for errors and following detection of a fault, transfers the fabric identity(world wide names) and all settings (mode parameters, encryption settings, etc.) over to the standbylink then activates that link. When properly configured the change is minimally disruptive to thehost and does not require any configuration changes on the host or in the backup application.If no drive commands are outstanding when a failure is detected, then the port change happenswith virtually no disruption to the SAN. If a command is outstanding on the link when a failure isdetected the drive is not able to recover the command so that command will fail but the applicationwill be able to continue to use the drive on the new path. Many applications are able to recoverfrom a single command failure as long as the communication path to the drive is not lost.

HP LTO-5 data path port failover overview 5

Figure 1 Data path port failover example configuration

HP LTO-5 control path failover overviewLibrary control path port failover (see Figure 2 (page 7)) may be configured with one drive hostingthe path to the library controller and a second drive configured as an alternate standby path tothe library controller. The library connections will share physical links with the drives but the librarywill have its own identity on the SAN. If data path port failover is also configured the library controlpath will follow the data path on link failures.The HP ESL G3 Tape Libraries provide an advanced library control path failover capability. Thelibrary will monitor the drive that is hosting the library controller and the ports on the drive. Thelibrary receives notification from the drive of any interface change events and can quickly detectwhether that change indicates a fault. The library monitors the drive and can detect when a drivehas been removed or otherwise becomes inaccessible. Upon detecting a fault that would causeloss of communication with the library controller the library will automatically move the librarycontrol path identity (world wide names) and all settings (such as reservations and prevent/allowsettings) over to the alternate control path drive and activate the control path on the alternate drive.When properly configured, the change is minimally disruptive to the host and does not requireany configuration changes on the host or in the backup application.The MSL tape libraries provide a basic control path failover capability. In the event of a failure ofthe drive hosting the library control path the library web interface may be used to take the controlpath drive offline and the library control path identity (world wide names) and all settings, (suchas reservations and prevent/allow settings)I , will be moved over to the alternate master driveautomatically. When properly configured the change is minimally disruptive to the host and doesnot require any configuration changes on the host or in the backup application.If no library commands are sent while the port is being reconfigured, the port change happenswith virtually no disruption to the SAN. Commands sent while the port is being reconfigured cannotbe processed and will fail. Applications that retry commands are able to use the library followingreconfiguration of the port. Applications that do not retry can be restarted remotely without makingany hardware configuration changes.

6 Overview

Figure 2 Control path port failover example configuration

HP LTO-5 control path failover overview 7

2 Technology for drive-assisted failoverThe drive-assisted failover features in HP LTO-5 drives use Fibre Channel switched fabric featuresto transfer a drive identity to a different port. The drive manages all of the SCSI configurations sothat the settings expected by the application are still present after the port change. In a typicalmulti-path configuration the application must manage both paths and reconfigure the drive anytime the active path is changed.Both data path port failover and control path port failover require at least one Fibre Channel switchbetween the drive and the host to provide some of the features required for failover with minimalhost disruption.

Technology for data path port failoverThe HP LTO-5 Fibre Channel tape drives configure both ports with identical worldwide names butonly one port will connect to the fabric. By default the port that completes speed negotiation firstwill become the active port. If the ports on the drive are connected to different speed fabric theport connected to the highest speed fabric will typically complete speed negotiation first. The HPMSL tape libraries that support data path port failover use the default behavior and do not allowselection of a preferred port.

Technology for control path failoverThe HP LTO-5 Fibre Channel tape drives use a technology called N-Port Identifier Virtualization(NPIV) which is defined as part of the Fibre Channel standards maintained by the INCITS/T11working group (see clause 6) in the FC-LS-2 specification. NPIV allows a single physical port toconnect to a Fibre Channel switch multiple times using multiple node and port names.

Traditional bridged library control pathA typical connection for a fibre channel tape library using the drive to bridge commands to thelibrary controller in a two drive tape library is shown in Figure 3 (page 9).

8 Technology for drive-assisted failover

Figure 3 Typical bridged library controller connection

In the typical bridge library controller connection each tape drive has one physical link to the SANswitch and connects to the SAN switch as one Fibre Channel device.The tape drive hosting the library controller path connects as one Fibre Channel device containingtwo logical units. The tape drive is logical unit number zero and the tape library is logical unitnumber one. Both devices are considered to be in the same Fibre Channel device which is calleda “Node”. The tape library Fibre Channel node contains a tape drive logical unit and a mediachanger logical unit. The logical view of the tape library is shown in Figure 4 (page 10).

Technology for control path failover 9

Figure 4 Logical view of traditional configuration

Virtual library connection using NPIVWhen configured to use library control path port failover the HP LTO-5 drive will use NPIV toconnect the library and the drive to a Fibre Channel switch as two different devices. The physicaldevice connection is the same as that shown in Figure 3 (page 9) with the internal connectionbetween the library and the drives passing the host commands from the drive to the library andthe link from the drive to the switch being shared.The logical view from the host is of three independent Fibre Channel devices. Two tape drivesappear as independent devices and neither tape drive contains a library controller logical unit.The library controller appears as a third independent device even though it is sharing the physicalconnection with one of the tape drives. The logical view and physical connections for a libraryusing NPIV and configured to use library control path port failover is shown in Figure 5 (page 11).


Figure 5 NPIV virtual library connection

With NPIV creating a virtual device on the switch port that the drive is connected, to both the tapedrive and the tape library are shown by the switch as independent devices even though they areconnected to the same physical port. As the library is presented to the host as an independentdevice it can be managed independently from the tape drive.


In Figure 5 (page 11) the tape library contains two drives with both tape drives connected to aFibre Channel switch. The library is presented as a virtual device using the same link one of thetape drives in the figure.When the tape library detects that the control path should fail over to an alternate path it is ableto disconnect the library from the physical link and reconnect the library to the switch over the linkused by the other drive without disrupting that link. Both drives could be active reading or writingand the library can be moved without disrupting the drive activity. The logical connection followinga control path failover event is shown in Figure 6 (page 13).


Figure 6 NPIV library connection following failover

Figure 6 (page 13) shows that the logical link for the library has moved and now shares the samephysical link as the top drive. No changes to the physical cabling were required and any otheractivity on the links was not disrupted.


3 Configuring failover for the ESL G3 Tape LibraryConfiguring data path failover

When data path failover is enabled, the drive will be presented on the first drive FC port, bydefault, and the second FC port is a passive port. If the primary port goes down, the library willtransfer various settings over to the passive port and then enable the failover port.Prerequisites for using data path failover:1. The ESL G3 Control Path Failover license must be installed on the library.2. Only LTO-5 Fibre Channel tape drives support data path failover.3. The library must be attached to an FC SAN that supports NPIV.4. The drive port FC topology must be in Fabric mode.5. The host FC port must have a physical path to both the first port and secondary (passive) port

on the FC drive; all of the devices need to be within the same zone for failover to work.

Enabling data path failoverTo enable data path failover:1. Log into the Management Console as a user with Administrator privileges.2. Select the Physical managed view.3. Select Setup > Partitions > Data Path Failover.4. The Data Path Failover (DPF) dialog will appear and display all LTO-5 drives. You can filter

the list by partition. Select the drives for which you want to enable DPF and then click OK.

NOTE: Any drives that belong to an access group and have hosts mapped to the secondport are considered to be custom mapped. DPF cannot be enabled on these drives until thecustom mapping is removed.

5. Wait for the configuration change to complete.

Verifying data path failoverTo verify that data path failover is configured use Monitor > Drives to launch the Drive Statusdialog. When data path failover is enabled for a drive:

• The Link Status for the drive is listed as Passive, meaning that this is the failover port.

• The Data Path Failover column displays Enabled.

To verify that data path failover is working:1. From the FC switch's management console, down the main FC port to a drive.2. To verify that failover occurred, use Monitor > Drives to launch the Drive Status dialog. The

link status for the first port will be Down and the link status for the second port will be Activeas shown in the highlighted line.

14 Configuring failover for the ESL G3 Tape Library

Diagnosing data path failoverWhen a drive failover occurs the Drives subsystem has Warning state, which is displayed in theOverall System Status section of the Management Console.

Click Drives to display the Event List, and then select the event and click Details to see moreinformation about the failover event. The Repair tab provides detailed instructions on how totroubleshoot and fix the problem.

Disabling data path failoverTo disable data path failover:1. Log into the Management Console as a user with Administrator privileges.2. Select the Physical managed view.3. Select Setup > Partitions > Data Path Failover.4. Uncheck the drive for which you want to enable DPF and then click OK.5. Wait for the configuration change to complete.6. Verify the configuration change by selecting Monitor > Drives. Data Path Failover is shown

as Disabled.

Configuring control path failoverPrerequisites for using control path failover:1. The ESL G3 Control Path Failover license must be installed on the library.2. Only LTO-5 Fibre Channel tape drives support data path failover.3. The library must be attached to an FC SAN that supports NPIV.

Configuring control path failover 15

4. The drive port FC topology must be in Fabric mode.5. The host FC port must have a physical path to both the first port and secondary (passive) port

on the FC drive; all of the devices need to be within the same zone for failover to work.6. The first FC port of the drive must be physically connected to the SAN because the library will

host the control path via the first port by default.If Secure Manager is enabled, hosts that have been granted access to the control path device mustbe mapped to the first FC port of the drive. If Secure Manager is enabled and managing hostaccess, a host can be granted robotics access only. Even though the primary or secondary driveis hosting the robotics device, a host does not need to be mapped to the failover drive device togain access to the robotics.

Enabling control path port failover on the libraryTo enable control path failover within a partition:1. Log into the Management Console as a user with Administrator privileges.2. Select the Physical managed view.3. Select Setup > Partitions > Control Path.4. The Secure Manager Partitions dialog will appear and display all available partitions. Select

the partition and click OK.5. The Control Path dialog will appear with the command path drive highlighted in yellow. Select

the second drive in the list and click OK.6. Click Yes in the Warning dialog to take the partition offline. Wait for the configuration change

to complete.

Configuration requirements after enabling control path failure

Library configurationThe drive port FC topology must be in “Fabric” mode.If Secure Manager is enabled, hosts that have been granted access to the control path device mustbe mapped to the first FC port of the drive.

SAN configurationWhen control path failover is enabled, the library is no longer presented as a logical unit behindthe tape drive and is assigned a new Fibre Channel node name. After configuring the control pathfailover parameters, you may need to make additional changes:

• Switches using world wide name zoning will have to be configured to allow access to thelibrary controller. If the switch interface does not allow manually entering a world wide name,


the zone for the primary control path can be configured and then a failover may be forcedto cause the secondary path to be enabled and the second zone configured. (To force afailover, see Section (page 17)).To find the world wide name assigned to the library controller, use the Monitor > Partitionsmenu to see the Partitions Status dialog. The world wide name for the library controller isshown in the LCP WWPN column.

• Hosts connecting to the library may need to be rebooted if the operating system does notsupport dynamic device detection.

• Applications on hosts may need to be reconfigured to recognize the new library world widename.

Verifying control path failoverBefore testing control path failover, verify that the configuration is correct in the Drive Status dialog,which is accessed from the Monitor > Drives menu. The Control Path column identifies the primaryand secondary control path drives. The drive currently hosting command path access is markedActive.

To test control path failover:1. From the Physical managed view, select Setup > Partitions > Control path.2. Select the partition with control path failover configured.3. The Control Path dialog for the partition appears. Click Failover.4. In the Warning dialog, click Yes.

NOTE: Since the control path is switching from the primary drive to the secondary drive,there could be a disruption in host traffic.

5. A progress dialog will appear while the failover operation is in progress.6. Select Monitor > Drives to launch the Drive Status dialog. The Secondary drive should now

be the Active drive.

Disabling control path failoverTo disable control path failover:1. Log into the Management Console as a user with Administrator privileges.2. Select the Physical managed view.


3. Select Setup > Partitions > Control Path.4. The Secure Manager Partitions dialog will appear and display all available partitions. Select

the partition and click OK.5. The Control Path dialog will appear with the command path drive highlighted in yellow and

the failover drive selected. Un-select the failover drive and click OK.6. Click Yes in the Warning dialog to take the partition offline. Wait for the configuration change

to complete. Once completed, the partition will automatically be put online.


4 Configuring failover for the MSL Tape LibrariesConfiguring data path port failover

Enabling data path port failoverData path failover may be used with the drive ports configured in loop mode or fabric mode. Forbest results and compatibility with control path failover HP recommends that the drive ports beconfigured in fabric mode and connected to a switch.Data path failover is configured for each drive using the drive configuration options in the librarynetwork management interface. Figure 7 (page 19) shows the drive configuration options in thelibrary network management interface. In this example data path port failover is enabled for drive1 but is not enabled for drive 2. Note that in this example control path port failover is also enabled.When control path port failover is enabled the port type is required to be fabric so the port typeselections are disabled.

Figure 7 Enabling data path port failover

Configuring data path port failover 19

Verifying data path port failoverAfter data path port failover is enabled, verify the configuration in the Drive: Status screen, asshown in Figure 8 (page 20).

Figure 8 Standby and active ports

After verifying that the configuration change was successful, verify that the hosts with access to thetape drive are still able to communicate with the drive.After verifying host access via the initial path a data path port failover may be forced bydisconnecting the cable from the active port on the drive.The drive status display shows which drive port is active and which port is in standby. Afterdisconnecting the cable from the active port verify that the library network management page portstatus shows that the active port has changed. Reconnect the disconnected port and verify that itshows as Standby. Verify that each host still has access to the tape drive.If a particular port is the preferred active port and it is configured as Standby you can force selectionof a particular port as the active port by disconnecting the cable from the other port.

Configuring control path failover

Enabling control path port failover on the libraryThe MSL libraries only support control path failover when used in a Fibre Channel SAN andconnected as fabric devices.The minimum configuration is:

• A library or partition within a library with two LTO-5 Fibre Channel drives of the same type(Ultrium 3000 half height or Ultrium 3280 full height)

• All drive ports configured to use a “Fabric N/F” connection

• All drive ports connected to a Fibre Channel switch that supports NPIV

20 Configuring failover for the MSL Tape Libraries

The default port configuration for the MSL tape libraries is Automatic and must be changed. Figure 9(page 21) shows the MSL tape library network administration drive configuration pane. Theconfiguration for port A is set correctly for use with control path failover. The configuration for portB is still set to the default setting of “Automatic”.

Figure 9 Configure library, control path failover configuration disabled

Figure 10 (page 22) and Figure 11 (page 22) show the System configuration pane. In Figure 10(page 22) the option for Enable Library Control Path Failover is not selectable and the option forAlternate Drive for Library Control Path Failover is set to N.A.. When the options for enablingcontrol path failover are not available the configuration requirements have not been met. Theconfiguration shown in Figure 9 (page 21) where only one drive port is configured for Fabric isan example configuration where these options would not be available. Selecting the Help link inthe note following the option will bring up a help page listing the configuration requirements.


Figure 10 Configure library, control path failover configuration disabled

In Figure 11 (page 22) the configuration requirements for enabling control path failover have beenmet and the library has made the option for Enable Library Control Path Failover selectable as wellas providing a selection for the “Alternate Drive for Library Control Path”.

Figure 11 Configure library, control path failover configuration available

Configuration requirements after enabling control path failureWhen control path failover is enabled, the library is no longer presented as a logical unit behindthe tape drive and is assigned a new Fibre Channel node name. After configuring the control pathfailover parameters, you may need to make additional changes:

• Switches using world wide name zoning will have to be configured to allow access to thelibrary controller. If the switch interface does not allow manually entering a world wide name,the zone for the primary control path can be configured and then a failover may be forcedto cause the secondary path to be enabled and the second zone configured. (To force afailover, see Verifying control path failover (page 23)). The library world wide name can befound in the Identity: Library page, as shown in Figure 12 (page 23).


Figure 12 Library world wide name displayed on the Identity: Library page

• Hosts connecting to the library may need to be rebooted if the operating system does notsupport dynamic device detection.

• Applications on hosts may need to be reconfigured to recognize the new library world widename.

Verifying control path failoverAfter enabling control path failover, verify the configuration of both ports. To verify both paths firstverify that the hosts configured for access to the library are able to communicate with the library.It may be necessary to modify switch zoning to enable access to the library. After the host accesshas been verified use the library front panel or the library management interface to power off thedrive marked as hosting the library logical unit number Drive 1 (LUN) in Figure 9 (page 21) -Configure: Drives.

NOTE: There is always a library logical unit number hosted by a drive so the (LUN) indicatordoes not change when control path failover is enabled. The library is presented as logical unitnumber zero on its own world wide node name when control path failover is enabled and ispresented as logical unit number one on the drive world wide node name when control path failoveris not enabled.

After the library has powered off the drive hosting the library control path, the LUN indicator shouldmove to the alternate control path drive. When the library has reported that the drive has beensuccessfully powered off and the LUN indicator has moved to the alternate control path drive,verify that host connectivity to the library has not changed. It may be necessary to configure switchzoning to allow host access.After verifying library connectivity using each of the library control paths the library control pathmay be moved back to the original drive if so desired by using the Alternate Drive for LibraryControl Path option (see Figure 11 (page 22)).

Hardware-specific requirements

Brocade switchesFor best reliability when control path failover is used Brocade switches should be running version3.2.2e, 3.4.1b, or newer.


Cisco switchesSome Cisco switches that support NPIV do not have NPIV enabled by default. The Cisco MDS9148may disable NPIV when power cycled.To enable NPIV on a Cisco switch use: Cisco_Device_Manager > Admin > Feature_Control or usethe Cisco CLI commands show npiv status and npiv enable.


5 Backup application test results for MSL Tape LibrariesHP has tested several common backup applications in number of typical configurations and thefollowing sections provide information on how the tested applications responded when data pathand control path failover events occurred.

Test descriptionsThe following tests simulate typical failure cases where a failover event may occur.

DPF test 1 — Broken linkTest description:Both drive 1 and drive 2 performing backup operations. While both of the drives are active andthe Fibre Channel links on both drives show activity, remove the cable to the active port on drive1 to simulate a broken link.Expectations:• Backup job on drive 2 should be uninterrupted

• Backup application should be able to use the library

• Backup application should continue to be able to use drive 1

• If the backup application is able to perform error recovery the job on drive 1 should resume

DPF test 2— Disabled portTest description:Both drive 1 and drive 2 performing backup operations. While both of the drives are active andthe Fibre Channel links on both drives show activity, disable the switch port for the active link ondrive 1..Expectations:• Backup job on drive 2 should be uninterrupted


• Backup application should continue to be able to use drive 1

• If the backup application is able to perform error recovery the job on drive 1 should resume

CPF test 1 — Normal: failed drive removalTest description:Drive 1 configured to host the library interface. Drive 1 is idle ready for replacement. Drive 2 isperforming a backup. Use the library web interface or front panel to disable drive 1 and removeit while drive 2 is actively reading or writing.Expectations:• Backup job on drive 2 should be uninterrupted

• Backup application should be able to use the library following drive removal.

CPF test 2 — Normal: install new driveTest description:Drive 1 removed from the library. Drive 2 is performing backups. Install a replacement drive inthe drive 1 location, enable that drive in Data Protector and perform a backup on drive 1.Expectations:

Test descriptions 25

• Backup job on drive 2 should be uninterrupted

• Backup application should be able to use the new drive 1

• Backup application should be able to use the library following drive installation

CPF test 3 — Error: disable active drive and cause failoverTest description:Backup operations in progress on both drive 1 and drive 2. Drive 1 is configured to host the librarycontroller. Use the library front panel or web management interface to disable drive 1 while abackup is in progress.Expectations:• Backup job on drive 2 should be uninterrupted


• Backup job on drive 1 should fail

• Recovery steps will be required to reuse the tape that was in drive 1

HP Data Protector on Microsoft WindowsConfiguration:• HP Data Protector version 6.2

• Windows Server 2008 R2

• HP Storage Works 8/40 SAN Switch(Firmware v6.4.1)

• HP 82E 2 Port 8Gb Fibre Channel HBA 1.11a5 firmware BIOS version 2.02a2 UB5.03a10

• HP MSL 4048 2 Ultrium-5 3280 Fibre Channel tape drives firmware I3BW

• HP DL380G7

Table 1 Data path failover test results for HP Data Protector on Microsoft Windows

ResultsTest

Drive 2 continued to operate without pause. Drive 1 activity paused for a short time followingthe link break and then resumed on the second port. The backup on both drives completedsuccessfully and the application was able to return the volumes to the source storage locations.

“Broken link” (page 25)


“Disabledport” (page 25)

Table 2 Control path failover test results for HP Data Protector on Microsoft Windows

ResultsTest

The backup on drive 2 continued uninterrupted while drive 1 was disabled and removed.Following the completion of the backup on drive 2 Data Protector was able to use the newlibrary control path hosted by drive 2 to move the volume back to the source storage location.

“Normal: failed driveremoval” (page 25)

HP Data Protector reported that drive 1 had been taken offline.

Drive 1 was able to be replaced and enabled without interruption to any activity. DataProtector was able to use all drives and the library following the drive replacement.

“Normal: install newdrive” (page 25)

The job on drive 1 failed and DP reported an error “The drive inside the library has beentaken offline and device is no longer available”. The backup job on drive 2 completed without

“Error: disable activedrive and causefailover” (page 26) interruption and Data Protector was able to use the new library control path hosted by drive

2 to move the volume back to the source storage location.Data Protector marked the media that was in drive 1 when the drive was taken offline as“poor”. To recover the media the operator needs to use the library interface to remove the

26 Backup application test results for MSL Tape Libraries

Table 2 Control path failover test results for HP Data Protector on Microsoft Windows (continued)

ResultsTest

media from the drive, use the Data Protector interface to recycle and export the media, andthen reformat the media.

HP Data Protector on Red Hat LinuxConfiguration• HP Data Protector version 6.2

• Red Had Enterprise Linux 5.5

• HP Storage Works 8/40 SAN Switch (Firmware v6.4.1)



• HP DL380G7

Table 3 Data path failover test results for HP Data Protector on Red Hat Linux

ResultsTest

Drive 2 continued to operate without pause. The backup on drive 1 failed. Following the errordrive 1 was still accessible by the host.


Drive 2 continued to operate without pause. The backup on drive 1 failed. Following the errordrive 1 was still accessible by the host.


Table 4 Control path failover test results for HP Data Protector on Red Hat Linux

ResultsTest








2 to move the volume back to the source storage location.Data Protector marked the media that was in drive 1 when the drive was taken offline as“poor”. To recover the media the operator needs to use the library interface to remove themedia from the drive, use the Data Protector interface to recycle and export the media, andthen reformat the media.

HP Data Protector on HP-UX 11iv3Configuration:• HP Data Protector version 6.2

• HP-UX 11iv3

• HP Storage Works 8/40 SAN Switch(Firmware v6.4.1a)



• HP Integrity rx2600

HP Data Protector on Red Hat Linux 27

Table 5 Data path failover test results for HP Data Protector on HP-UX 11iv3

ResultsTest





Table 6 Control path failover test results for HP Data Protector on HP-UX 11iv3

ResultsTest








2 to move the volume back to the source storage location.Data Protector marked the media that was in drive 1 when the drive was taken offline as“poor”. To recover the media the operator needs to use the library interface to remove themedia from the drive, use the Data Protector interface to recycle and export the media, andthen reformat the media.

Symantec Backup ExecConfiguration:• Symantec Backup Exec 2010 R2

• Windows Server 2008 R2




• HP DL380G7

Table 7 Data path failover test results for Symantec Backup Exec on Windows Server 2008 R2

ResultsTest

Drive 2 continued to operate without pause. Drive 1 activity paused for about 5 minutesfollowing the link break and then resumed on the second port. The backup on both drives


completed successfully and the application was able to return the volumes to the source storagelocations.




NOTE: If a backup is started immediately after data path port failover is enabled, Backup Execwill fail the backup and take the drive offline. The Backup Exec services should be restarted afterdata path port failover is enabled and before starting a backup.


Table 8 Control path failover test results for Symantec Backup Exec on Windows Server 2008 R2

ResultsTest

The backup on drive 2 continued uninterrupted while drive 1 was disabled and removed.Following the completion of the backup on drive 2 Backup Exec was able to use the newlibrary control path hosted by drive 2 to move the volume back to the source storage location.


At the start of the next backup, Backup Exec reported that a drive in the library had beentaken offline.

Drive 1 was able to be replaced and enabled without interruption to any activity. BackupExec was able to use all drives and the library following the drive replacement.


The job on drive 1 failed and Backup Exec reported an error “The drive hardware is offline.Please confirm that drive hardware is online and properly cabled”. The backup job on drive

“Error: disable activedrive and causefailover” (page 26) 2 completed without interruption and Backup Exec was able to use the new library control

path hosted by drive 2 to move the volume back to the source storage location.The inventory command in the administrator interface can be used to find the media in drive1 and return it to the source storage location. To reuse the media that was in drive 1 whenthe failure occurred use the Backup Exec administrator interface to format and label the media.

Symantec NetBackupConfiguration:• Symantec NetBackup 7.0

• Windows Server 2003 R2 SP2




• HP DL380G7

Table 9 Data path failover test results for Symantec NetBackup on Windows Server 2003 R2 SP2

ResultsTest







Table 10 Control path failover test results for Symantec NetBackup on Windows Server 2003 R2SP2

ResultsTest

The backup on drive 2 continued uninterrupted while drive 1 was disabled and removed.Following the completion of the backup on drive 2 NetBackup was able to use the new librarycontrol path hosted by drive 2 to move the volume back to the source storage location.


When the NetBackup user interface is refreshed it shows that a drive was taken offline.

Drive 1 was able to be replaced and enabled without interruption to any activity. NetBackupwas able to use all drives and the library following the drive replacement.


The job on drive 1 failed and NetBackup reported an error “The request could not beperformed due to an I/O error”. The backup job on drive 2 completed without interruption

“Error: disable activedrive and causefailover” (page 26)

Symantec NetBackup 29

Table 10 Control path failover test results for Symantec NetBackup on Windows Server 2003 R2SP2 (continued)

ResultsTest

and NetBackup was able to use the new library control path hosted by drive 2 to move thevolume back to the source storage location.After drive 1 was turned back on NetBackup moved the media back to the source storageslot and was able to use the media for further backups.


6 Backup application test results for ESL G3 Tape LibrariesHP has tested several common backup applications in number of typical configurations and thefollowing sections provide information on how the tested applications responded when data pathand control path failover events occurred.

Test descriptionsThe following tests intend to simulate the occurrence of a typical failover event.

DPF test 1 — Data path failover during backupTest description:A backup is run on the primary FC port. The primary FC port is disconnected or disabled whiledata is being written to the drive; the results are logged.Expectations:• The backup application should be able to continue to use the library.

• The backup application should continue to be able to use the secondary FC port.

• If the backup application is able to perform error recovery, the job on the failed over FC portand drive should resume automatically or be able to be restarted manually.

DPF test 2— Data path failover during restoreTest description:A restore is run on the primary FC port. The primary FC port is disconnected or disabled whiledata is being read from the drive; the results are logged.Expectations:• The backup application should be able to continue to use the library.

• The backup application should continue to be able to use the failed over secondary FC port.

• If the backup application is able to perform error recovery, the job on the failed over FC portand drive should resume automatically or be able to be restarted manually.

CPF test 1 — Control path failover during backups running on control path andnon-control path drives

Test description:Drive 1 is configured to host the library interface, making it the control path drive. Drive 2 isconfigured as the control path failover drive. While drive 1 and drive 2 are performing backups,during the portion of backup job when data is being written to the drives, all FC cables aredisconnected from drive 1.Expectations:• The backup job accessing drive 1 should fail and log errors, aborting the backup.

• The backup job on drive 2 should continue without interruptions.

• The backup application should be able to use the library following control path failover.

HP Data ProtectorTest configuration for Microsoft Windows:• HP Data Protector version 6.2 and 6.11


Test descriptions 31

• HP Storage Works 8/40 SAN Switch (Firmware v6.4.1b)

• HP 42B 2 Port 4Gb Fibre Channel HBA v2.3.0.2

• HP ESL G3 with 2 Ultrium-5 3280 Fibre Channel tape drives firmware I3FW

• HP DL580G5Test configuration for Red Hat Linux:• HP Data Protector version 6.11

• Red Hat Enterprise Linux v5 Update 5 (x64) Kernel: 2.6.18-194.el5 #1 SMP


• HP 81Q 8Gb Fibre Channel HBA BIOS 2.15 fw: 5.03.02 driver: 8.03.01.04.05.05-k


• HP DL380G7Test configuration for HP-UX 11iv3:• HP Data Protector version 6.11

• HP-UX 11.31 (ia64) September 2010 Release


• HP 81E 8Gb Fibre Channel HBA Emulex AH403A (LPe12002) Fw: 1.11a5 Driver:B.11.31.1003


• HP Integrity rx2600 SysBIOS:4.15

Table 11 Test results for HP Data Protector

ResultsTest

Passed. After the primary data port was disconnected, Data Protector paused the backup forsome time and then continued the backup on the secondary data path port. Data Protector

“Data path failoverduringbackup” (page 31) completed the backup on the same media. Library signaled an event: Data path Failover

in drive is failed over.

Passed. Data Protector pauses the restore for some time and then continues the restore on thesecondary port. The operation completes successfully. The library signals an event: DataPath Failover in drive is failed over.

“Data path failoverduring restoreoperation” (page 31)

NOTE: If the restore fails with the first attempt, Data Protector might mark the media aspoor, requiring a Recycle, Export and Import of the media, and then the restore passessuccessfully on the second attempt.

Passed. When backups were running on two drives, both FC ports on the control path drivewere disconnected. The library control path transferred to the second drive and the backup

“Control path failoverduring backups running

on second drive completed successfully without any interruption. The backup on first drive,on control path andwhich was the initial control path drive, did not complete as expected. Data Protector markedthe tape poor and generated the following messages:

non-control pathdrives” (page 31)

1. Cannot write filemark. I/O error on drive. (This is expected as the datapath to the drive has been lost)

2. Connection to media agent broken. Cannot eject the media andcannot unload exchanger medium from the backup application.

After the port was reconnected the backup was successful on other media. Successfully restoredthe files from the completed backup on the secondary drive, which was now the control pathdrive. The restored data was found to be identical to the source data.

IBM TSMTest configuration for Microsoft Windows:

32 Backup application test results for ESL G3 Tape Libraries

• IBM TSM version 6.1.5





• HP DL580G5Test configuration for Red Hat Linux:• IBM TSM version 6.1.5





• HP DL380G7Test configuration for HP-UX 11iv3:• IBM TSM version 6.1.5





• Integrity rx2600 SysBIOS:4.15

Table 12 Test results for IBM TSM

ResultsTest

Passed. After the primary port was disconnected, TSM failed the backup with an error message:Server detected system error. The TSM server reported the following error: I/O

“Data path failoverduringbackup” (page 31) error on drive x with volume x. When restarted manually, the backup completed

successfully on the same tape device and with the same media. The restore completedsuccessfully. The restored data was found to be identical to source data.

NOTE: For HP-UX, TSM paused the backup, gave an error about the currently loaded media,mounted another piece of media, and then completed the backup.

Passed. Disconnected the active data port during the restore operation. TSM reported errorsServer detected system error and I/O error on drive x with volume x.

“Data path failoverduring restoreoperation” (page 31) Library reported a warning: Data path Failover in drive is failed over. When

restarted manually, the restore operation completed successfully with the same drive andmedia.

NOTE: For HP-UX, the restore paused and reported an error listing the failing restore file,and then the restore continued and completed the restore of the remaining files. Manuallyrestoring the missing files was successful.

Passed. When backups were running on two drives, both FC ports on the control path drivewere disconnected. The library control path transferred to the second drive and the backup


on second drive completed successfully without interruption, but the backup paused for someon control path andtime until the original control path drive produced an error. The backup on first drive, whichnon-control path

drives” (page 31) was the control path drive before initiating failover, did not complete as expected. TSMreported errors Server detected a system error and An I/O error occurredwhile accessing drive x. Access mode for volume x was set to "read-only" due towrite error.The library generated the following expected results:

IBM TSM 33

Table 12 Test results for IBM TSM (continued)

ResultsTest

1. DPF is failed over on the drive.2. CPF is failed over on the drive.3. Control of the network storage drive has failed.The original backup completed successfully after reconnecting the failed ports and manuallyrestarting the backup, TSM used a different piece of media from the media pool because thefirst media was marked as read-only. Successfully restored the completed backup from thesecondary drive, which was now the control path drive. The restored data was found to beidentical to the source data.

EMC NetworkerTest configuration for Microsoft Windows:• EMC Networker version 7.6.1





• HP DL580G5Test configuration for Red Hat Linux:• EMC Networker version 7.6.1





• HP DL380G7Test configuration for HP-UX 11iv3:• EMC Networker version 7.6.1





• Integrity rx2600 SysBIOS:4.15

Table 13 Test results for EMC Networker

ResultsTest

Passed. After the primary port was disconnected, Networker marked the tape as full, ejectedthe media, mounted another media, and completed the backup. The library generated an

“Data path failoverduringbackup” (page 31) event: Data path Failover in drive is failed over. Restore completed

successfully and Networker mounted both media for restore. The data was identical to thesource data.

Manual intervention was required on Windows. When the active data port was disconnectedduring the restore operation, the recovery operation failed in Networker. The tape entered

“Data path failoverduring restoreoperation” (page 31) service mode and Networker gave an error: the specified network resource is

no longer available. Networker then attempted to eject the tape and was unsuccessful.


Table 13 Test results for EMC Networker (continued)

ResultsTest

The library reported an event: The data path on drive has failed. When the restoreoperation was restarted, Networker gave a read open error and a serial number mismatcherror. In this case, the user needs to delete the jukebox and configure it again to completethe restore operation.On HP-UX and Red Hat, Networker reported an I/O error on the drive, however, the restoreoperation completed successfully on the failover port. Data was found to be identical withsource data.

Manual Intervention Required. When backups were running on two drives, both FC ports onthe control path LTO drive were disconnected. The library control path transferred to the


second drive and the backup on the second drive completed successfully without anyinterruption.

on control path andnon-control pathdrives” (page 31) The backup on first drive, which was the control path drive before initiating the failover event,

did not complete as expected. Networker marked the tape as full and ejected the tape fromthe first backup drive, requiring manual intervention to stop the backup. After reconnectingthe failing port, Networker mounted another tape and attempted to start the backup job againon the first drive. The backup then completed.The library generated the following expected results:1. DPF is failed over on the drive.2. CPF is failed over on the drive.3. Control of the network storage drive has failed.The files were successfully restored from the completed backup. The restored data was foundto be identical to the source data. Successfully completed the failed back up by manuallyrestarting it on the second drive.

Symantec Backup ExecTest configuration for Microsoft Windows:• Backup Exec version 2010 R2





• HP DL580G5

Table 14 Test results for Backup Exec

ResultsTest

Passed. After the primary data path port was disconnected, Backup Exec completed thebackup operation after a pause of approximately 7 minutes.

“Data path failoverduringbackup” (page 31)

Passed. After the primary data path port was disconnected Backup Exec continued andcompleted the restore operation after a pause of approximately 7 minutes. The restored datawas found to be identical to the source data.


Passed. When backups were running on two drives, both FC ports on the control path LTOdrive were disconnected. The backup job on drive 1 failed and Backup Exec reported an


error: The drive hardware is offline. Please confirm that driveon control path andnon-control pathdrives” (page 31)

hardware is online and properly cabled. The backup job on drive 2 completedwithout interruption and Backup Exec was able to use the new library control path hosted bydrive 2 to move the volume back to the source storage location. The restored data was foundto be identical to the source data on the second drive.

Symantec Backup Exec 35

CommVault SimpanaTest configuration for Microsoft Windows:• CommVault Simpana version 9



• HP 82Q 2 Port 8Gb Fibre Channel HBA BIOS: 2.15, fw: 5.03.02, driver: 9.1.9.25


• HP DL380G7Test configuration for Red Hat Linux:• CommVault Simpana version 9





• HP DL380G6Test configuration for HP-UX 11iv3:• CommVault Simpana version 9





• HP Integrity BL870c SysBIOS:4.25

Table 15 Test results for CommVault Simpana

ResultsTest

Passed. After the primary data path port was disconnected, the Simpana application generatedan error code 40:74 and automatically resumed after approximately 20 minutes or could beresumed manually. The backup completed successfully.


Passed. After the primary data path port was disconnected, the Simpana application generatedan error code 40:74 and successfully completed the restore operation. The restored data wasfound to be identical to the source data.


Passed. When backups were running on two drives, both FC ports on the control path LTOdrive were disconnected. The library control path transferred to the second drive and thebackup on the second drive completed successfully without interruption.

“Control path failoverduring backups runningon control path and

The backup on first drive, which was the control path drive before initiating the failover, didnot complete as expected. The control path was successfully passed to the drive 2 path. Drive

non-control pathdrives” (page 31)

1 changed from Pending state to Waiting. Failed to unmount media from Drive 1 as expecteddue to no active fibre connections.

CA ARCserveTest configuration for Microsoft Windows:• CA ARCserve v15




• HP 82Q 2 Port 8Gb Fibre Channel HBA fw: 5.03.02, Driver: v9.1.9.25


• HP DL580G5

Table 16 Test results for Backup Exec

ResultsTest

Passed. After the primary data path port was disconnected the backup operation completedsuccessfully.


Passed. After the primary data path port was disconnected the restore operation completedsuccessfully.


Passed. When backups were running on two drives, both FC ports on the control path LTOdrive were disconnected. The library control path transferred to the second drive and the


backup on second drive completed successfully without interruption. The backup on the firston control path anddrive, which was the control path drive before initiating the failover, did not complete asnon-control path

drives” (page 31) expected. However, the drive was not off-lined by the application. When attempting to useARCserve to eject the tape, a hardware error was returned and the drive was finally off-lined.

CA ARCserve 37

7 Support and other resourcesHP technical support

Telephone numbers for worldwide technical support are listed on the HP support website:www.hp.com/support.Collect the following information before calling:

• Technical support registration number (if applicable)

• Product serial numbers

• Product model names and numbers

• Error messages

• Operating system type and revision level

• Detailed questions

• An L&TT Support Ticket, which can be downloaded to a USB drive from the front panel ordownloaded to a file with the remote management interface.

For continuous quality improvement, calls may be recorded or monitored.

HP websitesFor additional information, see the following HP websites:

• www.hp.com — HP corporate website

• www.hp.com/go/storage — HP storage products

• www.hp.com/go/ebs — compatibility information

• www.hp.com/support — HP Support website

• www.hp.com/support/mslg3tstree — interactive troubleshooting tool

• www.docs.hp.com — documentation about HP products

• www.hp.com/support/tapetools — HP Library & Tape Tools diagnostic softwareThe Fibre Channel specifications, including the specifications for NPIV, are maintained by theINCITS/T11 Committee. See http://www.t11.org.Copies of the Fibre Channel specifications are available from the INCITS store. See http://www.incits.org.

Typographic conventionsTable 17 Document conventions

ElementConvention

Cross-reference links and e-mail addressesBlue text: Table 17 (page 38)

Website addressesBlue, underlined text: www.hp.com

Bold text • Keys that are pressed

• Text entered into a GUI element, such as a box

• GUI elements that are clicked or selected, such as menu andlist items, buttons, tabs, and check boxes

Text emphasisItalic text

38 Support and other resources

http://www.hp.com/support/

http://www.hp.com

http://www.hp.com/go/storage

http://www.hp.com/go/ebs

http://www.hp.com/service_locator

http://www.hp.com/support/mslg3tstree

http://www.hp.com/support/manuals

http://www.hp.com/support/tapetools

http://www.t11.org

http://www.incits.org

http://www.incits.org

http://www.hp.com

Table 17 Document conventions (continued)

ElementConvention

Monospace text • File and directory names

• System output

• Code

• Commands, their arguments, and argument values

Monospace, italic text • Code variables

• Command variables

Emphasized monospace textMonospace, bold text

WARNING! Indicates that failure to follow directions could result in bodily harm or death.

CAUTION: Indicates that failure to follow directions could result in damage to equipment or data.

IMPORTANT: Provides clarifying information or specific instructions.

NOTE: Provides additional information.

TIP: Provides helpful hints and shortcuts.

Subscription serviceHP recommends that you register your product at the Subscriber's Choice for Business website:www.hp.com/go/e-updates.After registering, you will receive e-mail notification of product enhancements, new driver versions,firmware updates, and other product resources.

HP-authorized resellerFor the name of your nearest HP-authorized reseller:• In the United States, call 1–800–282–6672

• Elsewhere, visit the HP website: www.hp.com, then click Contact HP to find locations andtelephone numbers.

Subscription service 39

http://www.hp.com/go/e-updates

http://www.hp.com

hplto-5tapelibraries …h20628. · hplto-5tapelibraries usingdatapathfailoverandcontrolpath...

Documents