HP Smart Array Multipath Software User Guide
December 2005 (Fourth Edition) Part Number 354907-004
Copyright 2005 Hewlett-Packard Development Company, L.P. The information contained herein is subject to change without notice. The only warranties for HP products and services are set forth in the express warranty statements accompanying such products and services. Nothing herein should be construed as constituting an additional warranty. HP shall not be liable for technical or editorial errors or omissions contained herein. Confidential computer software. Valid license from HP required for possession, use or copying. Consistent with FAR 12.211 and 12.212, Commercial Computer Software, Computer Software Documentation, and Technical Data for Commercial Items are licensed to the U.S. Government under vendors standard commercial license. Microsoft, Windows, and Windows NT are U.S. registered trademarks of Microsoft Corporation. UNIX is a registered trademark of The Open Group. Linux is a U.S. registered trademark of Linus Torvalds.

Audience assumptions

This document is for the person who installs, administers, and troubleshoots servers and storage systems. HP assumes you are qualified in the servicing of computer equipment and trained in recognizing hazards in products with hazardous energy levels.

Contents

Overview..... 5
Software overview..... 5 Software distribution..... 5 Minimum requirements.... 5 Supported operating systems..... 6 Microsoft feature support.... 6 Linux feature support.... 6 Multiple operating system support.... 6 Supported four-node configurations.... 6 Two-server external boot configuration.... 6 Two-server internal boot configuration... 7 Two-server mixed boot configuration... 7 Two-server cluster configuration.... 7 Three-server external boot configuration... 7 Three-server internal boot configuration.... 8 Three-server mixed boot configuration... 8
Installation and operation in Microsoft environments... 9
Pre-installation hardware setup for Microsoft.... 9 Uninstalling the Smart Array Multipath software driver... 10 Installation for an existing 2-node cluster with Microsoft Windows 2000... 10 Multipath installation for Microsoft.... 11 Post-installation hardware setup for Microsoft.... 11 Microsoft browser security settings.... 11 Static LUN balancing.... 12
Installation and operation in Red Hat Enterprise Linux 2.1 environments.. 14
Pre-installation configuration for Red Hat Enterprise Linux 2.1... 14 Editing the active kernel..... 14 Modifying the RAIDTAB configuration file.... 16 Multipath installation for Red Hat Enterprise Linux 2.1.... 19 Static load (read-only) balancing in Red Hat Enterprise Linux 2.1... 20
Installation and operation in Red Hat Enterprise Linux 3.0 and 4.0 environments. 21
Pre-installation hardware setup for Red Hat Enterprise Linux 3.0 and 4.0... 21 Multipath installation for Red Hat Enterprise Linux 3.0 and 4.0... 21 Post-installation configuration for Red Hat Enterprise Linux 3.0 and 4.0... 22 Static load (read-only) balancing in Red Hat Enterprise Linux 3.0 and 4.0.. 23
Installation and operation in UnitedLinux environments... 24
Pre-installation hardware setup for UnitedLinux.... 24 Multipath installation for UnitedLinux.... 24 Post-installation configuration for UnitedLinux.... 25 Static load (read-only) balancing in UnitedLinux... 26

Troubleshooting.... 27

Problem diagnosis..... 27 Problems during installation..... 27 HBA failure..... 28 Cable failure..... 28
Acronyms and abbreviations.... 29

Index..... 30

Overview

In this section

Software overview.... 5 Software distribution.... 5 Minimum requirements.... 5 Supported operating systems.... 6 Supported four-node configurations... 6

Software overview

Smart Array Multipath software delivers dual path functionality and supports failover capability for a redundant HBA in a server with redundant cabling to an HP StorageWorks Modular Smart Array 500 Generation 2 storage system. This fault-tolerant tool enhances availability in clustering and DAS solutions with up to two servers managing up to 2 TB of stored data. The software supports multiple I/O paths to the same logical volumes. When a path fails, the software moves the logical drives from the failed path to the path of the redundant HBA in the same server. Smart Array Multipath software works differently with Microsoft and Linux products to provide specific features that are compatible with operating system functionality.

Supported four-node configurations
The following sections identify supported multipath configurations with their respective 4-Port Shared Storage Module connections and locations for boot and data volumes. These configurations require two or three servers attached with four SCSI cables to the MSA500 G2 storage system.
Two-server external boot configuration
All boot and data volumes reside on the MSA500 G2 storage system.

Overview 6

Server 1 2

Port (bus) A1 B1 A2 B2

Boot volume location Storage system* Storage system*
Data volume location Storage system Storage system
*Red Hat Enterprise Linux operating systems support boot volumes on servers only. For a mixed or external boot configuration in a multiple operating system environment, always locate Linux boot volumes on servers.
Two-server internal boot configuration
Boot volumes reside on their respective servers, while data volumes reside on the MSA500 G2 storage system.
Server Port (bus) A1 B1 A2 B2 Server 2 Storage system Boot volume location Server 1 Data volume location Storage system
Two-server mixed boot configuration
One boot volume resides on its respective server, while the other boot volume resides on the MSA500 G2 storage system. Both data volumes reside on the MSA500 G2 storage system.
Server Port (bus) A1 B1 A2 B2 *Red Hat Enterprise Linux operating systems support boot volumes on servers only. For a mixed or external boot configuration in a multiple operating system environment, always locate Linux boot volumes on servers. Server 2 Storage system Boot volume location Storage system* Data volume location Storage system
Two-server cluster configuration
Identical servers (hardware and software configuration) connect to the MSA500 G2 storage system. Boot volumes reside on their respective servers, while both data volumes reside on the storage system.
Three-server external boot configuration
All boot and data volumes reside on the MSA500 G2 storage system. One server connects to two ports.

Overview 7

Server 3
Boot volume location Storage system* Storage system* Storage system*
Data volume location Storage system Storage system Storage system
Three-server internal boot configuration
Boot volumes reside on their respective servers, while data volumes reside on the MSA500 G2 storage system. One server connects to two ports.
Server 3 Port (bus) A1 B1 A2 B2 Server 2 Server 3 Storage system Storage system Boot volume location Server 1 Data volume location Storage system
Three-server mixed boot configuration
Two boot volumes reside on their respective servers, while one boot volume resides on the MSA500 G2 storage system. All data volumes reside on the MSA500 G2 storage system. One server connects to two ports.
Server 3 Port (bus) A1 B1 A2 B2 Server 2 Server 3 Storage system Storage system Boot volume location Storage system* Data volume location Storage system

Overview 8

Installation and operation in Microsoft environments
Pre-installation hardware setup for Microsoft... 9 Uninstalling the Smart Array Multipath software driver... 10 Installation for an existing 2-node cluster with Microsoft Windows 2000.. 10 Multipath installation for Microsoft... 11 Post-installation hardware setup for Microsoft.... 11 Microsoft browser security settings.... 11 Static LUN balancing.... 12
Pre-installation hardware setup for Microsoft
To prepare for software installation:
Complete the MSA500 G2 storage system hardware installation:
NOTE: For hardware and option installation procedures, refer to the storage system user guide or the documentation that ships with the option.
a. Install the MSA500 G2 storage system. b. Install the 4-Port Shared Storage Module. c. Install the MSA500 G2 controllers. d. Update the system firmware, if needed. 2.
Complete the server installation:
a. Install all hardware, including a second supported HBA. Refer to the server user guide.
IMPORTANT: The server only supports one SCSI path during installation. If the server is already cabled for a multipath configuration, disconnect the SCSI cable connected from the redundant HBA to the storage system.
b. Install one of the supported operating systems. c. Reboot the server. 3. 4.
Install multipath cabling for one of the supported four-node configurations (on page 6). Be sure that only one SCSI cable is connected from the server to the MSA500 G2 storage system. During installation, the Smart Array Multipath software supports only one SCSI path per Microsoftbased server. Power up the storage system. Wait for the controller display to provide a Startup Complete message. Power up one of the servers.
Installation and operation in Microsoft environments 9
Uninstalling the Smart Array Multipath software driver
CAUTION: Before uninstalling the software driver in a Microsoft Windows Server 2003 clustering environment, use the Cluster Administrator to stop the cluster service on the appropriate node.

1. 2. 3. 4. 5. 6.

Power down the server. Disconnect all SCSI cables from any controller in the storage system, unless the boot drive is attached. Power up the server. Select Start>Settings>Control Panel. Select Add/Remove Programs. From the list of components, select HP Smart Array Multipath Software 2.0C.
NOTE: For Microsoft Windows Server 2003 only, the selection is HP Smart Array Multipath Driver.

Click Change/Remove. Click OK.
NOTE: A Microsoft Windows Server 2003 system does not indicate progress during the removal. Wait at least 10 minutes to allow the system to complete the removal.

Click Cancel.

10. Shut down the server. 11. Disconnect the SCSI cable from the redundant HBA.
Installation for an existing 2-node cluster with Microsoft Windows 2000
1. 2. 3. 4. 5. 6. 7. 8. 9.
Log on to one node of the cluster with an account having domain administrator privileges. Open the Cluster Administrator and move all cluster groups to the second node. On the first node, stop the cluster service and set the startup type to Manual. Install the HP Smart Array Multipath Software. Refer to "Multipath installation for Microsoft (on page 11)." Reboot as instructed. Log on to Windows 2000 with an account having domain administrator privileges. Click Yes or OK for any new hardware found or installed. Shut down the system. Do not reboot. Install the second HBA and connect the cable from second HBA to the storage system.
10. Power up the server. 11. Log in to Windows 2000 with an account having domain administrator privileges after the startup

completes.

12. Start the cluster service and set the startup type to Automatic. 13. Open the Cluster Administrator. 14. Move the disk groups from the second node to the first node and verify that all groups come online. 15. Repeat all steps for the second node.
Installation and operation in Microsoft environments 10
Multipath installation for Microsoft
CAUTION: Before installing Smart Array Multipath Software, be sure to uninstall any previous versions of the software and update the HBA and MSA500 G2 controller drivers.
Insert the Smart Array Multipath Software CD into the CD-ROM drive of the server.
IMPORTANT: If autorun is disabled, run setup.exe from the CD.

2. 3. 4.

To agree to the software license agreement, click Agree. When the Main screen displays, select Install Multipath Software. Click OK.

IMPORTANT: If HP web-based applications have not been installed on the system, the Web-based Management Setup Wizard displays. The wizard prompts you to provide an administrator login and password. Follow the on-screen instructions. The CD installs the Smart Array Multipath Manager, the ProLiant Storage Manager, and the redundancy driver.

5. 6. 7. 8. 9.

When the system prompts for a reboot, remove the CD then click Cancel. Shut down the server. Connect the SCSI cable to the redundant HBA. Power up the server. After the server boots, open a browser window and enter: https://localhost:2381 The system prompts you with a security certificate.
10. To accept the certificate and proceed to the login, select Yes. 11. Enter the administrator login and password.
The System Management Homepage displays.
12. Click the Settings tab. 13. Click Options. 14. In the Configuration Options section, select Local Access. 15. Click Save Configuration. 16. Repeat steps 1 through 15 for each server connected to the MSA500 G2 storage system.
Post-installation hardware setup for Microsoft
To prepare for software operation:

1. 2. 3. 4.

Reconnect the SCSI cable from the redundant HBA to the MSA500 G2 storage system. Cycle the server power. Repeat steps 1 and 2 for each server. Use the appropriate software for multipath operations.
Microsoft browser security settings
For Windows Server 2003, the modified version of Internet Explorer 6.0 defaults all servers to the Internet zone, which enables the highest level of security. At this security level, browsing to HP Management agents generates many security messages.
Installation and operation in Microsoft environments 11
To avoid these security messages:

1. 2. 3. 4. 5.

Open Internet Explorer 6.0. Select Tools>Internet Options. Select the Security tab. Click Local intranet. Manually set the servers to the Local intranet zone by entering: http://<servername or IP address>:2301 https://<servername or IP address>:2381

Static LUN balancing

The Smart Array Multipath software and Microsoft operating system support static LUN balancing. The movement of drives to specific paths can be done two ways:

Locally with a DME Remotely with the Smart Array Multipath found on the Smart Array Multipath Software CD From the desktop, right-click My Computer. Click Manage. The Device Manager window opens. Click SCSI and RAID Controllers. Right-click one of the array controller icons and click Properties. When the Properties window opens, click the Redundancy Configuration tab. From the Redundancy Configuration tab, the administrator can view the following controller information:
To balance LUNs with the DME:
Name Slot number Status Slot number of redundant controller Controller tree
In the controller tree, right-click one of the logical volumes and then click Switch Path. The system moves the logical volume to the other path. First-time users must install the software. Install the ProLiant Storage Manager software and Smart Array Multipath Manager software ("Multipath installation for Microsoft" on page 11). Browse to the System Management Homepage by entering: https:\\<name of server>:2381
To manage your redundant configuration:
IMPORTANT: If you encounter numerous security messages on a Microsoft Windows Server 2003 platform, review the Microsoft browser security settings (on page 11).

3. 4. 5. 6. 7.

To accept the security certificate, click Yes. The system may prompt for the administrator password established during the original software installation. The System Management Homepage opens. Click the Home tab. Select ProLiant Storage Manager. A new window opens. Click the appropriate controller on the Device View tab. Click Multipath Management. The Multipath Management and Configuration screen displays.
Installation and operation in Microsoft environments 12
From the Multipath Management and Configuration screen, do one of the following:
To move all drives from the current path to the redundant path, click the link for the controller and select Switch All Paths. The system moves all drives to the redundant path. To move a drive from one path to the redundant path, click the link for the drive and select Switch Path.
IMPORTANT: After establishing a redundant configuration and adding a logical volume, use Windows Disk Manager to detect the new volume.

Open the configuration menu. Enter: make menuconfig Select Multi-device support (RAID and LVM). Select RAID support. Be sure that the RAID support option is checked with an asterisk. If it is not checked, use the space bar to cycle through the settings until an asterisk appears next to the option. Select Multipath I/O support. Be sure that the Multipath I/O support option is set as a module. If it is not set as a module, use the space bar to cycle through the settings until an M appears next to the option. Press the Esc key twice to exit the menus. When prompted to save the new kernel configuration, press the Enter key to select Yes. Make the kernel:
a. From the root level, enter:
mrproper make dep make bzImage make modules make modules_install
b. Wait for the kernel to be made. Depending on the hardware configuration, this process can last

up to 30 minutes.

10. Insert the new kernel into GRUB or LILO.
Installation and operation in Red Hat Enterprise Linux 2.1 environments 15
a. Copy the new kernel boot image to the /boot directory (use the Tab key to autocomplete
directory names or display possible options). Name the boot image vmlinuz-xxxx where xxxx is the kernel version number with the name you used in the very first step (ex., vmlinuz-2.4.9Emultipath). cp /usr/src/linux-xxx/arch/ixxx/boot/bzImage /boot/vmlinuz-xxxxx
b. Make the boot image bootable:
mkinitrd vmlinuz-xxxx xxxxx
c. Update the GRUB or LILO configuration file to include the new kernel, by doing one of the

following:

To update GRUB, edit /boot/grub/menu.lst in a text editor, copy one of the entries and change the values to match those of the new kernel boot image and the title GRUB will use to display. For LILO, edit the /etc/lilo.conf by copying one of the entries and changing the values to match those of the new kernel boot image and the title LILO will use to display. To apply the new configuration, run the following command: /sbin/lilo The new kernel is ready for use.
11. Reboot and select the new kernel at the GRUB or LILO prompt. If the new kernel does not work
properly, select the original kernel to boot from and remake the kernel or reconfigure the operating system.

Installing the module without modifying the kernel
Load the module. Enter: insmod multipath Verify that the module is installed and loaded by listing all modules. Enter: lsmod
The kernel is now ready for multipath operations, but to support multipath, you must enter these commands each time the server is restarted.
Modifying the RAIDTAB configuration file
To perform multipath operations with a Linux operating system, a raidtab configuration file must be present. Use the instructions in the following sections to be sure the raidtab configuration file contains the appropriate information.

RAIDTAB terms

Observe the following definitions for raidtab terms:
raiddevintroduces the configuration for a particular device nr-raid-disksthe number of raid disks in the array; specified in the /dev/cciss directory persistent-superblockmust be set to 1 if an md device is to be mounted/used during a reboot chunk-sizesets the stripe size in bytes, in the power of 2 devicethe physical device that makes up the RAID array raid-diskthe index of the device in the RAID array
For more information, refer to the operating system documentation.
Installation and operation in Red Hat Enterprise Linux 2.1 environments 16
Sample RAIDTAB configuration file
The following raidtab sample file is for a multipath configuration with three partitions (/dev/md0, /dev/md1, and /dev/md2) where each md device represents a partition on the device. If another partition is needed, add it as /dev/md3 with the same characteristics as the preceding partitions. The limit for number of partitions is four primary partitions. However, creating one of the four partitions as a type type 0xf Win 95 Extd (LBA) partition enables you to create extended logical partitions inside of the primary partition. Inside of the extended partition, you can create additional Linux partitions. The raidtab configuration file must reside in the /etc directory. The contents of /etc/raidtab should resemble the following:
raiddev /dev/md0 raid-level nr-raid-disks persistent-superblock chunk-size device raid-disk device raid-disk raiddev /dev/md1 raid-level nr-raid-disks persistent-superblock chunk-size device raid-disk device raid-disk raiddev /dev/md1 raid-level nr-raid-disks persistent-superblock chunk-size device raid-disk device raid-disk multipath 8 /dev/cciss/c0d2p/dev/cciss/c1d2pmultipath 8 /dev/cciss/c0d2p/dev/cciss/c1d2pmultipath 8 /dev/cciss/c0d2p/dev/cciss/c1d2p1 1
Completing the Linux multipath setup
After a valid raidtab file is created in the /etc directory, verify that the correct drivers and modules are loaded.
Verify that the md and multipath drivers are loaded, either statically or by a module load. Enter: lsmod
Installation and operation in Red Hat Enterprise Linux 2.1 environments 17
This command reveals which modules are running. Examining the boot-time messages reveals the static loaded drivers. IMPORTANT: If you have made configuration changes to the kernel (including the multipath or /dev/md driver) and have not rebooted from the new kernel, you must reboot before continuing. Red Hat typically includes the md driver in the kernel.

Verify that the md driver is in the kernel. Enter: dmesg | grep md | more This command shows the boot-time messages. If the md driver was loaded, several messages should appear, similar to the following messages: md: md driver version X.X md: Autodetecting RAID arrays md: autorun md: autorun DONE
If the multipath driver was built as a module but not loaded, load the module. Enter: insmod multipath This command loads the driver. If the driver does not load the multipath module, rebuild the module.
After verifying loaded drivers, make the raid files. For the sample partition table in the "Sample RAIDTAB Configuration File (on page 17) section, enter: mkraid /dev/md0 mkraid /dev/md1 mkraid /dev/md2 mkraid /dev/md3
CAUTION: Do not use Fdisk or mkraid to create any other partitions on this logical drive. This action results in data corruption and data loss.
If mkraid responds that the partition contains existing data, do the following:
a. Force the mkraid to run. Enter:

mkraid f

b. Make filesystems on the raid devices. Enter:
mkfs t ext2 /dev/md0 mkfs t ext2 /dev/md1 mkfs t ext2 /dev/md2 mkfs t ext2 /dev/md3 mkfs t ext2 /dev/md4 IMPORTANT: The example in step 5b uses ext2 because known bugs in the ext3 filesystem can cause data corruption.
The multipath RAID device should be functioning. To mount the device /dev/md0, enter: mount /dev/md0 /spare_filesystem If necessary, you can stop or start the RAID device with the following commands:
To stop the RAID device, enter: raidstop /dev/md0 This command may need to start the md device after a reboot. Place the command in the rc /etc configuration files for mounted filesystems at boot time.
Installation and operation in Red Hat Enterprise Linux 2.1 environments 18
To start the RAID device, enter: raidstart /dev/md0 This command can be placed in shutdown scripts in /etc.
Pre-installation hardware setup for Red Hat Enterprise Linux 2.1
a. Install all hardware, including a second supported HBA. Refer to the server user guide. b. Install one of the supported operating systems. c. Reboot the server.

3. 4. 5.

Install multipath cabling for one of the supported four-node configurations (on page 6). Power up the storage system. Wait for the controller display to provide a Startup Complete message. Power up one of the servers.
Multipath installation for Red Hat Enterprise Linux 2.1

Use the following procedure for supported versions of Red Hat operating systems. IMPORTANT: Red Hat Enterprise ES/AS users must obtain the RPM and DDI files from the OS base media. To use the Smart Array Multipath Software with a Linux operating system, download the required driver RPM. To download the driver RPM:

1. 2. 3. 4. 5. 6. 7. 8.

Insert the Smart Array Multipath Software CD into the CD-ROM drive of the server. Open a console prompt. Mount the CD-ROM. Change to the Linux directory. List the contents of the directory and select the proper RPM for the current operating system. Install the proper RPM using the following command: rpm -ihv cpq_cciss_<os version>.i386.rpm After successful installation, reboot the server. Repeat steps 1 through 7 for each server connected to the MSA500 G2 storage system.
Installation and operation in Red Hat Enterprise Linux 2.1 environments 19
Static load (read-only) balancing in Red Hat Enterprise Linux 2.1
The Smart Array Multipath software and Linux operating system support static load (read-only) balancing functionality. To create, add, or extend logical volumes, use ACU Version 7.10 or later. Locate ACU on the SmartStart CD. Refer to the HP Array Configuration Utility User Guide on the SmartStart CD or refer to the HP website (http://www.hp.com).
Installation and operation in Red Hat Enterprise Linux 2.1 environments 20
Installation and operation in Red Hat Enterprise Linux 3.0 and 4.0 environments
Pre-installation hardware setup for Red Hat Enterprise Linux 3.0 and 4.0.. 21 Multipath installation for Red Hat Enterprise Linux 3.0 and 4.0... 21 Post-installation configuration for Red Hat Enterprise Linux 3.0 and 4.0... 22 Static load (read-only) balancing in Red Hat Enterprise Linux 3.0 and 4.0.. 23
Pre-installation hardware setup for Red Hat Enterprise Linux 3.0 and 4.0
Multipath installation for Red Hat Enterprise Linux 3.0 and 4.0
Use the following procedure for supported versions of Red Hat Enterprise Linux operating systems. To use the Smart Array Multipath Software with a Linux operating system, download the required driver RPM. To download the driver RPM:
Installation and operation in Red Hat Enterprise Linux 3.0 and 4.0 environments 21

2. 3. 4. 5. 6. 7. 8.

Open a console prompt. Mount the CD-ROM. Change to the Linux directory. List the contents of the directory and select the proper RPM for the current operating system. Install the proper RPM using the following command: #rpm_-Uhv --replacefiles cpq_cciss_<os version>.i686.rpm After successful installation, reboot the server. Repeat steps 1 through 7 for each server connected to the MSA500 G2 storage system.

Post-installation configuration for Red Hat Enterprise Linux 3.0 and 4.0
After installing Smart Array Multipath software on a server with a Red Hat Enterprise Linux operating system, configure for multipath operations. Review the following sample configuration procedure. This sample assumes that the user wants to set /dev/cciss/c1d0p2 and /dev/cciss/c2d0p2 to point to the same volume as a multipath device. To configure the system for multipath use:
Be sure that the MSA500 G2 storage system contains two identical MSA500 G2 controllers connected to the same logical volume. To create multipath device /dev/md0, run: mdadm -create -level multipath n 2 /dev/md0 /dev/cciss/c1d0p2 /dev/cciss/c2d0p2
To review the status, run: mdadm D /dev/md0 Results should look similar to the following: /dev/md0 Version : 00.90.00 Creation Time : Mon Apr 29 09:15:Raid Level : multipath Array Size : 14683328 (14.00 GiB 15.08 GB) Raid Devices : 2 Total Devices : 2 Preferred Minor : 0 Persistence : Superblock is persistent Update Time : Mon Apr 29 09:02:State : dirty, no-errors Active Devices : 2 Working Devices : 2 Failed Devices : 0 Spare Devices : 0

Number 0 106

Major 2

Minor 0

RaidDevice active sync

State /dev/cciss/c2d0p2

Installation and operation in Red Hat Enterprise Linux 3.0 and 4.0 environments 22

active sync

/dev/cciss/c1d0p2
UUID : b1ec5895:5ed49b44:7ec7d4a8:397e19b1
IMPORTANT: You can also review status by running: cat /proc/mdstat Results would look similar to the following: Personalities : [multipath] read_ahead 1024 sectors md0 : active multipath cciss/c2d0p2[0] cciss/c1d0p2[1] 14683328 blocks [2/2] [UU] unused devices : <none>

4. 5. 6.

To format the volume, run: mkfs t ext2 /dev/md0 To mount the volume, run: mount /dev/md0 /spare_filesystem To make md device available after reboot, run: echo 'DEVICE <device1. devicen>'> /dev/mdadm.conf mdadm-detail-scan>>/etc/mdadm.conf For more information run: man mdadm
Configuration is complete.
Static load (read-only) balancing in Red Hat Enterprise Linux 3.0 and 4.0
Installation and operation in Red Hat Enterprise Linux 3.0 and 4.0 environments 23
Installation and operation in UnitedLinux environments
Pre-installation hardware setup for UnitedLinux... 24 Multipath installation for UnitedLinux.... 24 Post-installation configuration for UnitedLinux... 25 Static load (read-only) balancing in UnitedLinux.... 26
Pre-installation hardware setup for UnitedLinux

Multipath installation for UnitedLinux
Use the following procedure for supported versions of UnitedLinux operating systems. To use the Smart Array Multipath Software with a Linux operating system, download the required driver RPM. To download the driver RPM:

1. 2. 3.

Insert the Smart Array Multipath Software CD into the CD-ROM drive of the server. Open a console prompt. Mount the CD-ROM.
Installation and operation in UnitedLinux environments 24

4. 5. 6. 7. 8.

Change to the Linux directory. List the contents of the directory and select the proper RPM for the current operating system. Install the proper RPM using the following command: #rpm_-Uhv --replacefiles cpq_cciss_<os version>.i586.rpm After successful installation, reboot the server. Repeat steps 1 through 7 for each server connected to the MSA500 G2 storage system.
Post-installation configuration for UnitedLinux
After installing Smart Array Multipath software on a server with a UnitedLinux operating system, configure for multipath operations. Review the following sample configuration procedure. This sample assumes that the user wants to set /dev/cciss/c1d0p2 and /dev/cciss/c2d0p2 to point to the same volume as a multipath device. To configure the system for multipath use:

Number 1 105

Major 2 2

Minor 0 1

RaidDevice active sync active sync
State /dev/cciss/c2d0p2 /dev/cciss/c1d0p2
IMPORTANT: You can also review status by running:
Installation and operation in UnitedLinux environments 25
cat /proc/mdstat Results would look similar to the following: Personalities : [multipath] read_ahead 1024 sectors md0 : active multipath cciss/c2d0p2[0] cciss/c1d0p2[1] 14683328 blocks [2/2] [UU] unused devices : <none>
To format the volume, run: mkfs t ext2 /dev/md0 To mount the volume, run: mount /dev/md0 /spare_filesystem
Static load (read-only) balancing in UnitedLinux
Installation and operation in UnitedLinux environments 26

Troubleshooting

Problem diagnosis..... 27 Problems during installation.... 27 HBA failure..... 28 Cable failure..... 28

Problem diagnosis

When a problem exists with the multipath I/O, consult the Insight Management Agents and do one of the following:
For Microsoft operating systems:
Use the ProLiant Storage Manager or ProLiant Multipath Manager FAQs. Use the ProLiant Storage Manager with ProLiant Multipath Manager software and the DME to identify I/O path status.
For Linux operating systems, use the following command to identify HBA status, multipath status, and I/O block transfer size: cat /proc/mdstatus

Problems during installation
This section provides systematic instructions on what to try and where to go for help for the most common problems encountered during software installation. If you encounter problems during installation:

1. 2. 3. 4. 5. 6. 7.

In a Microsoft environment, be sure to uninstall any previous version of the multipath software first. Be sure that the firmware is upgraded for all HBAs and both MSA500 G2 controllers, if installed. Be sure that the hardware installation meets the minimum requirements (on page 5). Be sure that the SCSI cabling matches one of the supported four-node configurations (on page 6). Be sure that the HBA is functioning properly. Refer to the appropriate server and HBA documentation. If the HBA has failed, refer to "HBA failure (on page 28)." Be sure that the SCSI cables are functioning properly. If a SCSI cable fails, refer to "Cable failure (on page 28)." Be sure that you followed operating system-specific instructions:
If the server has a Red Hat operating system, be sure that the active kernel is edited properly. If the server has a Microsoft operating system, be sure that the SCSI cable from the redundant HBA was disconnected before Smart Array Multipath software installation.
If these steps do not solve the installation problem, contact an authorized reseller.

Troubleshooting 27

HBA failure
If one of the HBAs in the server fails, the redundant HBA performs all I/O operations. To replace the failed HBA:
Power down the HBA in one of the following ways:
For a PCI-based HBA in a Microsoft operating system environment, use the PCI Hot Plug functionality in the server to power down the HBA while the server is online. For an embedded HBA in a Microsoft operating system environment, power down the server. For an HBA in a Linux operating system environment, power down the server.

2. 3. 4. 5. 6.

Disconnect the SCSI cable from the connector on the HBA or from the external VHDCI connector on the server. Remove the failed HBA. Refer to the server maintenance and service guide. Install a replacement HBA. Refer to the documentation that ships with the server or HBA. Connect the SCSI cable to the connector on the HBA or to the external VHDCI connector on the server. Power up the HBA in one of the following ways:
Use PCI Hot Plug functionality to restore power. Power up the server.
IMPORTANT: In a Microsoft environment, the software recognizes the replacement HBA and automatically restores redundancy.
If operating in a Linux environment, reconfigure the I/O for multipath operation.

Cable failure

To replace the failed cable:
Disconnect the SCSI cable:
a. Disconnect the cable from the MSA500 G2 storage system. b. Disconnect the cable from the connector on the HBA or from the external VHDCI connector on the