Booting Linux x86 and x86_64 systems from a Storage Area Network with Device Mapper Multipath Enabling the High Availability feature for Operating System Partitions Fifth Edition Document Overview ........................................................................................................................... 2 Intended Audience ......................................................................................................................... 2 Assumptions ..................................
Document Overview This white paper helps you understand the concepts and configuration of boot from SAN and enabling multipath features for the Root partition on SAN in deployments using Device Mapper multi-path. It includes recommendations for implementing and configuring operating system installation partitions to enable the Device Mapper multipath feature on your Linux server.
Configuring boot from SAN Boot from SAN has become a de facto description for the capability of having a server boot its operating system from SAN. The HBA ROM provides this functionality. Once HBAs are configured to boot from the disk device on the SAN, the server boots as if it were a local disk. More than one HBA can be configured for the redundant boot path for the High Availability of the Boot device. The Failover feature during boot time is provided by the HBA ROM configuration.
Figure 2 b. Select the NIC to which the boot option is to be set and press Enter twice. Figure 3 c. Select iSCSI Boot and press Enter. Figure 4 d. iSCSI Boot must be displayed as the boot option for the NIC you selected.
3. Press Escape, and then press F10 to save your configuration and exit the utility. Configuring HBA/NIC ROM This section details the steps to configure the Host Bus Adapter to boot from SAN.
Qlogic HBA ROM configuration To configure the boot device for high availability on HP ProLiant servers, complete the following steps: 1. While the server is booting, press Ctrl+Q to enter Fast!UTIL. 2. From the Select Host Adapter menu, select the HBA you want to boot, and press Enter. Figure 6 3. From the Fast!UTIL Options menu, select Configuration Settings, and press Enter.
4. From the Configuration Settings menu, select Adapter Settings, and press Enter. Figure 8 5. From the Adapter Settings menu, change Host Adapter BIOS to Enabled by pressing Enter. Figure 9 6. Press ESC to go back to the Configuration Settings menu Figure 8. 7. Select Selectable Boot Settings, and then press Enter. 8. From the Selectable Boot Settings menu, enable the Selectable Boot option by pressing Enter, move the cursor to Primary Boot Port Name, LUN, and press Enter.
9. From the Select Fibre Channel Device menu, select the controller Port Name of the array and press Enter. Figure 11 10. From Select LUN menu, select the device to boot from, and press Enter. Figure 12 Note: LUN index in the previous figure corresponds to the Lun ID of the boot device presented to the host. 11. From the Selectable Boot Settings menu, to configure the secondary boot paths, select Boot Port Name, Lun. Repeat Step 8 and Step 9 for all the other controller ports of the array.
Figure 13 12. Save the changes by pressing ESC twice, and then select Save Changes. This saves the configuration changes to selected HBA. 13. From the Fast!UTIL Options menu, choose Select Host Adaptor option, and press Enter. Select the other HBAs (Figure 6) and repeat the steps 2 to 12 to configure the HBA for booting the server. Note: Refer to the “Booting Itanium Linux systems from a storage area network application notes” for the procedure to configure the HBA ROM on an Itanium server.
Emulex HBA ROM configuration To configure the boot device for high availability on HP ProLiant servers, complete the following steps: 1. While the server is booting, press Alt+E when the following message appears: Press To Go To Emulex BIOS Utility. 2. The Emulex BIOS utility displays Emulex Adapters in the system. At the Enter a Selection prompt, select the HBA index number. Figure 14 3. From the HBA configuration menu screen, select option 2, Configure This Adapter’s Parameters. Figure 15 4.
Figure 16 5. From the Configure Adapter’s Parameters screen (Figure 16) select option 4, Topology Selection, (Advanced Option). 6. From the Topology Selection menu, select option 4, Fabric Point to Point. Press Esc twice. 7. From the HBA configuration menu (), select option 1, Configure Boot Devices. 8. In the Saved Boot Devices list, select 1 as the primary boot path. Figure 17 9. At the Select Two-Digit Number of the Desired Boot Device prompt, enter the index of the desired controller port.
Figure 18 10. Enter the LUN ID of the starting LUN at the prompt. The devices are scanned starting from the entered LUN ID. Figure 19 11. At the prompt, enter the index of the Boot device from the list.
Figure 20 12. Select option 1, Boot this device via WWPN. Figure 21 13. From the Saved device list menu (Figure17), configure the alternate paths for boot devices by selecting the unused entries and repeating steps 9 to 12. 14. From Emulex Adapters menu (Figure 14), configure the other HBAs by repeating steps 2 to 13. 15. Exit from the BIOS menu and reboot the server.
HP Smart Array P700m Controller ORCA Configuration To configure the boot device for high availability on HP ProLiant servers, complete the following steps: 1. While the server is booting, press F8 when the HP Smart Array P700m controller is discovered, to go to Option Rom Configuration for Arrays (ORCA). 2. At the Main Menu of the ORCA utility, select Select Boot Volume and press Enter. Figure 22 3. At Boot Volume Enclosure Menu, select External and press Enter. Figure 23 4.
Figure 24 5. At Menu Select Boot Volume, select the Lun to be configured as Boot partition. Figure 25 6. Press F8 to save as Boot Volume. Figure 26 7. Press Enter to configure alternate paths to boot device, else go to Step 9. 8. At the External Boot Volume Menu, select the other controller port WWID by repeating steps 4 to 6. 9. Press ESC to exit the ORCA.
HP SC08Ge SAS HBA configuration To configure the HP SC08Ge SAS HBA as the boot controller, complete the following steps: 1. While the system is booting, press F9 to start the ROM-Based BIOS Setup Utility. 2. Select Boot Controller Order. a. Select the SCSI Mass Storage Controller, configured to provide the boot device and move it to Controller Order 1. b. Incase of multiple HBAs, set to the next higher Controller Order. 3. Press Escape, and then press F10 to save your configuration and exit the utility.
# 06/15/06 jpd # # Consult the IETF iSP iSCSI for details of these items. # ## # Name of the iSCSI Target. Must match what the target offers. # Hard coded Target IP .. No DNS support # TargetName= iqn.1986-03.abc.as:asddfrt.dsa23243 TargetIP=12.234.45.123 TargetPort=3260 TargetIP2=12.234.45.124 TargetPort2=3260 ## # local name the iSCSI client will present to the Target # and local IP settings. No DNS or DHCP support # InitiatorName=iqn.1234-98.com.asfd:19.23456ghg12:name InitiatorIP=12.234.34.
Installing the operating systems Root partition on SAN has become popular with blade systems and virtualization technologies. Multipath feature support for operating system installation partitions was introduced with the latest operating system distributions. OS vendors have provided the feature for enabling high availability for the installation partitions on the SAN.
Figure 28 b. Select Add iSCSI targets and click Add drive. Figure 29 c. Enable network Interface for the currently used NIC.
Figure 30 d. Enter the target IP address. Figure 31 e. Repeat step a to d to add more iSCSI targets. 4. While creating partitions during the installation process, you will see multipath devices (/dev/mapper/mpath*). Create the installation partitions using multipath devices. Multipathing feature will be enabled for all the operating system partitions created on multipath device during installation.
Figure 32 5. Ensure that iscsi-initiator-utils and device-mapper-multipath packages are selected in the package list.
Figure 34 6. Complete the installation and reboot the server. Note: • If the installation partitions are on a XP array, comment the following line in "defaults section" in the /etc/multipath.conf file: prio_callout • "/bin/true" If the installation partitions are on a MSA2xxxsa array, comment the following line in "device section" of the MSA2xxxsa array in the /etc/multipath.
Figure 35 b. Provide the parameters “withiscsi=1” to the kernel boot line for SLES11. Figure 36 2. To add the iSCSI devices for installation, complete the following step, else go to Step 3: a.
Figure 37 b. Configure the IP information. Figure 38 c. Ensure that the “Initiator Name” is correct. Figure 39 d. Setting up the target IP: • For SLES10 operating systems ensure that only one target IP is connected and the Start-Up is set to automatic.
Figure 40 • For SLES11 operating systems ensure that more than one target IP set. By default only one target IP is connected. Add new target IPs using the “Add” button under the Connected Targets tab. Figure 41 • Enter the Target IP address and click Next.
Figure 42 • Click Connect to connect to the target IP. Figure 43 • Change the Start-Up to automatic by using the toggle set-up button. 3. Select the device for installing the operating system: • For SLES11 operating systems, complete the following steps: a. b. Select the DM devices to create installation partitions. By default, DM devices are not listed. To list the DM devices select Hard Disks.
c. d. Click Configure > Configure Multipath > Yes > Yes. Select the DM devices to create installation partitions. Figure 44 • For SLES10 operating systems, select SAN devices for installation partitions. 4. While creating the installation partitions, select either of the following options: • If you intend to use the “user_friendly_names” with device mapper multipath devices select “by-label” fstab option.
Modify "root=/dev/disk/by-id/cciss-3xxxxxxxxxxxxxxxxxxxxxx" to "root=/dev/disk/byid/scsi-3xxxxxxxxxxxxxxxxxxxxxx" in /boot/grub/menu.lst. • Modify "/dev/disk/by-id/cciss-3xxxxxxxxxxxxxxxxxxxxxx" to "/dev/disk/by-id/scsi3xxxxxxxxxxxxxxxxxxxxxx" in /etc/fstab. 9. Enable multipath services to start at boot time by running the following commands: ~foo# chkconfig boot.multipath on ~foo# chkconfig multipathd on 10. Add device mapper multipath kernel module to initrd image by completing the following steps: a.
Additional Information For detailed information about HBAs, switches, storage arrays, and storage software, go to the following websites: Table 1 Topic HP website HBAs and switches Storage array systems Device Mapper Multipath software Integrity servers http://h18006.www1.hp.com/storage/saninfrastructure.html http://h18006.www1.hp.com/storage/arraysystems.html http://www.hp.com/go/devicemapper http://www.hp.
