Installation and Reference Guide Device Mapper Multipath Enablement Kit for HP StorageWorks Disk Arrays Version 4.0.
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Contents About this guide . . . . . . . . . . . . . . . . . . . . . . . . . . Intended audience . . . . . . . . . . . Document conventions and symbols . . . HP technical support . . . . . . . . . . Helpful websites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Introduction to HPDM Multipath . .
Tables 1 Document conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2 Hardware and Software Prerequisites 9 . . . . . . . . . . . . . . . . . . . . . . . . 3 HP Recommended configuration parameters 4 . . . . . . . . . . . . . . . . . . . . 14 4 Basic operations of HPDM Multipath . . . . . . . . . . . . . . . . . . . . . . . . 22 5 Abbreviations 29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
About this guide HP Device Mapper Multipath (HPDM Multipath) software kit is an HP released Device Mapper multipath binary based on Device Mapper included in Linux operating system distributions with enablement for HP StorageWorks Disk Arrays.
IMPORTANT: Provides clarifying information or specific instructions. NOTE: Provides additional information. HP technical support Telephone numbers for worldwide technical support are listed on the HP support website: http://www.hp.
1 Introduction to HPDM Multipath This chapter addresses the following topics: • • • • • Overview Features What's New Software Components HPDM Multipath Operation Overview HPDM Multipath software kit is an HP released Device Mapper multipath binary, based on Device Mapper Multipath included in Linux Operating System distributions, with enablement for HP StorageWorks Disk Arrays. Device Mapper is an infrastructure in the Linux kernel. It provides a generic way to create virtual layers of block devices.
• Provides support for XP20000/XP24000 Disk Arrays. • Provides support for EVA iSCSI devices on RHEL5/RHEL5.1/SLES9 SP3/SLES9 SP4/SLES10/SLES10 SP1. Software Components This section discusses the following software components of Device Mapper Multipath: • dm-multipath kernel module -- Routes I/O and provides failover to paths and path groups. • multipath configuration tool -- Provides commands to configure, list, and flush Multipath devices. • multipathd daemon -- Monitors path status.
2 Installing HPDM Multipath This chapter addresses the following topics: • HPDM Multipath Support Matrix • Installing HPDM Multipath Tools • Setting Up HPDM Multipath HPDM Multipath Support Matrix Table 2 lists the hardware and software prerequisites for installing HPDM Multipath. Table 2 Hardware and Software Prerequisites System Feature Operating system versions Supported hardware and software Red Hat Enterprise Linux 4 Update 5 Red Hat Enterprise Linux 4 Update 6 Red Hat Enterprise Linux 5 errata 2.6.
Supported arrays EVA 3000 (HSV101) VCS 4.007 or later EVA 5000 (HSV111) VCS 4.007 or later EVA 4000 (HSV200) XCS 5.110/6.100 or later EVA 6000 (HSV200) XCS 5.110/6.100 or later EVA 8000 (HSV210) XCS 5.110/6.100 or later EVA 4100 (HSV200) XCS 6.110 or later EVA 6100 (HSV200) XCS 6.110 or later EVA 8100 (HSV210) XCS 6.
• For all OS: aaa_base acl attr bash bind-utils bison bzip2 coreutils cpio cpp cracklib cvs cyrus-sasl db devs diffutils e2fsprogs file filesystem fillup findutils flex gawk gdbm-devel glibc glibc-devel glibc-locale gpm grep groff gzip info insserv kbd less libacl libattr libgcc libselinux libstdc++ libxcrypt m4 make man mktemp module-init-tools ncurses net-tools netcfg openldap2-client openssl pam pam-modules patch permissions popt procinfo procps psmisc pwdutils rcs readline sed strace syslogd sysvinit ta
Configuring Emulex HBA Parameters To configure the Emulex HBA parameter, complete the following steps: 1. For Emulex lpfc family of HBAs: • In RHEL4 hosts, edit the /etc/modprobe.conf file with the following values: options lpfc lpfc_nodev_tmo=14 lpfc_lun_queue_depth=16 lpfc_discovery_threads=32 • In SLES9 hosts, edit the /etc/modprobe.conf.local file with the following values: options lpfc lpfc_nodev_tmo=14 lpfc_lun_queue_depth=16 lpfc_discovery_threads=32 • In SLES10 hosts, edit the /etc/modprobe.
3 Configuring HPDM Multipath This chapter addresses the following topics: • Using /etc/multipath.conf File • Starting HPDM Multipath Using /etc/multipath.conf File The first step of configuring HPDM Multipath involves editing the /etc/multipath.conf configuration file, which is distributed as part of the HPDM Multipath tools user space package. This file also enables you to customize HPDM Multipath for a variety of SAN storage subsystems . The multipath.
Table 3 HP Recommended configuration parameters Description Attribute Supported values path_grouping_policy Used for applying the policy to the multipath device hosted by this storage controller multibus: All valid paths in one priority group group_by_prio: One priority group per path priority value path_checker Used for determining the state of the path tur path_selector Used to select the path selector algorithm to be used for mpath.
For EVA4000/6000 - (HSV200) device { vendor product path_grouping_policy getuid_callout path_checker path_selector prio_callout rr_weight rr_min_io failback no_path_retry "HP" "HSV200" group_by_prio "/sbin/scsi_id -g -u -s /block/%n" tur "round-robin 0" "/sbin/mpath_prio_alua %n" uniform 100 immediate 12 } For EVA5000-(HSV111) device { vendor product path_grouping_policy getuid_callout path_checker path_selector prio_callout rr_weight rr_min_io failback no_path_retry "COMPAQ" "HSV111 \(C\)COMPAQ" group_
For EVA4400 (HSV300) device { vendor product path_grouping_policy getuid_callout path_checker path_selector prio_callout rr_weight rr_min_io failback no_path_retry "HP” "HSV300" group_by_prio "/sbin/scsi_id -g -u -s /block/%n" tur "round-robin 0" "/sbin/mpath_prio_alua /dev/%n" uniform 100 immediate 12 } For MSA A/A arrays device { vendor product path_grouping_policy getuid_callout path_checker path_selector prio_callout rr_weight failback hardware_handler no_path_retry rr_min_io "HP” "MSA VOLUME*" grou
device { vendor product path_grouping_policy getuid_callout rr_weight rr_min_io path_checker failback no_path_retry "HP” "OPEN-*" multibus "/sbin/scsi_id -g -u -s /block/%n" uniform 100 tur immediate 12 } NOTE: For MSA 2000 Storage Product Family arrays (MSA2012fc/MSA2212fc/MSA2012i, add the device section in /etc/multipath.conf file. For HP recommended device parameters, see For MSA2000 Storage Product Family arrays.
Configuring HPDM Multipath
4 Using HPDM Multipath This chapter addresses the following topics: • Creating an Alias using /etc/multipath.conf file • Using Multipath Map • Supporting Clustering Solutions Creating an Alias using /etc/multipath.conf file This section describes various parameters available for updating /etc/multipath.conf file. The multipath devices are created in the /dev/mapper directory in the hosts.
udev_dir polling_interval selector path_grouping_policy getuid_callout prio_callout path_checker rr_min_io rr_weight failback no_path_retry user_friendly_names /dev 5 "round-robin 0" failover "/sbin/scsi_id -g -u -s /block/%n" "/bin/true" tur 1000 uniform immediate 12 no wwid path_grouping_policy path_checker path_selector 3600508b30090f5d0d2a9d64590490022 multibus tur "round-robin 0" } multipaths { multipath { } multipath ……. { …... for other target } multipath ……. { …...
For example, in a typical configuration, a Linux host with a dual port HBA is connected to an EVA 4000 through two switches. In this case, if all the paths are available, the host has four I/O paths for any LUN presented from the EVA 4000. The multipath.
Example 3. Failover and Failback If group A has sdad and sdo, and group B has sdj and sdy, the failover occurs from group A to group B and the failback occurs from group B to group A . The state of the path is given as [ready] [active] if the path is up, and ready for I/O. If the path is down, this state is shown as [faulty] [failed]. The path states are updated periodically based on the polling interval set in the /etc/multipath.conf file. The path states are updated by the multipathd daemon.
Configuring SteelEye LifeKeeper with HPDM Multipath Devices HPDM Multipath devices in the clustered environment can be used for file systems having Lifekeeper as the clustering solution. To configure HPDM Multipath devices, complete the following steps: 1. Configure the SAN such that each host has multiple paths to the array. Present the LUN’s to all the hosts. 2. Any file systems on the LUN’s must be mounted using the HPDM Multipath device. 3.
Using HPDM Multipath
5 Removing HPDM Multipath Tools This chapter addresses the following topic: • Removing HPDM Multipath Tools Removing HPDM Multipath Tools You can remove HPDM Multipath tools by using the INSTALL.sh shell script. To remove HPDM Multipath tools from your system, complete the following steps: 1. Log in to the system as a root user. 2. From the directory containing the script INSTALL.sh, execute the # ./INSTALL.sh command. 3. Follow the on-screen instructions. 4.
Removing HPDM Multipath Tools
6 Troubleshooting Following are the troubleshooting steps for issues that you may encounter while using HPDM Multipath: • Enter the following commands whenever a new LUN is added or deleted at the Linux host, to update the multipath maps in the kernel: 1. /etc/init.d/multipathd restart 2. multipath -v • Enter the following commands whenever multipath devices are deleted using multipath -F, to create the multipath devices and to create the same for the partitions on the multipath devices: 1.
Troubleshooting
7 Abbreviations Table 5 lists the abbreviations or terms used in this document.
