Release Notes. EMC PowerPath for Linux. Version 4.3. P/N Rev A09. June 7, 2005

Transcription

1 R E L E A S E N O T E S EMC PowerPath for Linux Version 4.3 Release Notes P/N Rev A09 June 7, 2005 Revision History: June 7, 2005, May 13, 2005, April 11, 2005, February 22, 2005, January 14, 2005, January 4, 2005, December 20, 2004 These release notes contain information about features, system requirements, and limitations of PowerPath 4.3.0, 4.3.1, and for Linux. The release notes supplement other PowerPath 4.3.x documentation. Topics include: Product Description...2 New Features and Changes...2 Environment and System Requirements... 5 Known Problems and Limitations Installation...22 Documentation...23 Software Media, Organization, and Files...24 Troubleshooting and Getting Help

2 Product Description Product Description EMC PowerPath for Linux software is a server-resident, performance and application availability enhancing software solution. PowerPath combines multiple path I/O capabilities, automatic load balancing, and path failover functions into one integrated package. PowerPath operates on Red Hat Enterprise Linux 3.0, SuSE Linux Enterprise Server 8, and Asianux 1 servers connected to EMC Symmetrix, EMC CLARiiON, IBM ESS, Hitachi Lightning, and HP StorageWorks xp, EVA, EMA, and MA storage systems in standalone and clustered configurations. PowerPath supports Fibre Channel for both switched fabric and arbitrated loop environments. New Features and Changes PowerPath 4.3.x has the following new features and changes. PowerPath PowerPath for Linux adds support for: RHEL 3.0 Update 4 and Update 5 EMC Symmetrix and CLARiiON iscsi storage systems. PowerPath PowerPath for Linux supports the following new features: Asianux Linux 1.0 (Red Flag 4.1 and Miracle Linux 3.0). Symmetrix 5x71 microcode. With Symmetrix 5x71 microcode, PowerPath supports Symmetrix devices that have device numbers greater than 8k. Utility Kit PowerPath for Symmetrix. Utility Kit PowerPath provides basic failover only, for Symmetrix and CLARiiON storage systems only. Utility Kit PowerPath for Symmetrix is supported in single HBA configurations where the same HBA is connected to each port on two separate Fibre Adapters (FAs) of a Symmetrix system through a switch or fabric. 1. Asianux is not supported on PowerPath EMC PowerPath for Linux Version 4.3 Release Notes

3 New Features and Changes Utility Kit PowerPath for Symmetrix protects against FA port failures and back-end storage-system failures, and supports non-disruptive upgrade (NDU) of storage system software. While a server is running normally, Utility Kit PowerPath takes no action. If a failure occurs in an FA port, Utility Kit PowerPath attempts to fail over (transfer) the I/Os to a different FA port. Utility Kit PowerPath does not protect against HBA failures. To protect against such failures in storage systems with multiple HBAs connected to a storage system, you must order PowerPath and an accompanying license. PowerPath PowerPath for Linux added support for the following features: PowerPath adds support for the following third-party storage systems: Hitachi Lightning and HP StorageWorks xp storage systems. HP StorageWorks EVA, MA, and EMA storage systems. IBM ESS storage systems. New PowerPath path management features include: Support for CLARiiON LUN names. With PowerPath 4.3.0, the powermt display command displays user-assignable CLARiiON LUN names as well as logical device IDs. New powermt commands. PowerPath provides the following new powermt commands to support third-party arrays and CLARiiON LUN names: powermt unmanage Excludes from PowerPath management a specified logical device or storage array class. This command is available for third-party arrays only. powermt manage Returns to PowerPath management logical devices or storage array classes previously excluded using powermt unmanage. This command is available for third-party arrays only. EMC PowerPath for Linux Version 4.3 Release Notes 3

4 New Features and Changes powermt display unmanaged Displays the individual logical devices of a managed class that have been unmanaged using powermt unmanage dev=. This command is available for third-party arrays only. powermt release Releases PowerPath pseudo device (emcpower) names for later reuse. powermt update lun_names Retrieves from the storage system the latest user-assignable CLARiiON LUN names. Available for CLARiiON storage systems only. Refer to the PowerPath Product Guide, P/N , for more information. PowerPath has one license key that enables all the functionality of PowerPath PowerPath Enterprise and Enterprise Plus licenses are supported for backward compatibility. These licenses enable all the capabilities of a PowerPath license. Changed Behavior in PowerPath In PowerPath 4.3.0, the /etc/init.d/powerpath stop command, the modprobe -r power_path command, and uninstalling PowerPath do not unload the HBA module along with the PowerPath modules. This differs from previous releases of PowerPath, which would unload the HBA modules. PowerPath 3.0.x Features Not Supported in PowerPath 4.3.x PowerPath 4.3.x for Linux does not support: Red Hat 2.1 To use PowerPath on a Red Hat 2.1 system, you must use the latest version of PowerPath 3.0.x for Linux, available on the Powerlink website SuSE SLES8 SP2a 4 EMC PowerPath for Linux Version 4.3 Release Notes

5 Environment and System Requirements Environment and System Requirements Before you install PowerPath, or whenever you make changes to the host or storage environment where PowerPath operates, consult the following resources: EMC Support Matrix EMC host connectivity guide for your operating system (CLARiiON and Symmetrix systems only) These resources, which are described in this section, will help you configure an environment in which all components, including PowerPath, can operate optimally. EMC Support Matrix (all storage systems) The EMC Support Matrix provides detailed information about the hardware, software, and networked storage components that are tested and compatible with both EMC storage systems and third-party storage systems. (For information about third-party storage systems, refer to the chapter entitled Non-EMC Storage.) The EMC Support Matrix describes supported host models, operating system revisions, host bus adapters, and connectivity devices. The EMC Support Matrix, which is updated every month, is published at the Powerlink website The support matrix is available in two formats: The EMCLink E-Lab Navigator (formerly ESN Builder) link is a Web-based, searchable database configurator. The Interoperability Matrices link lets you download the EMC Support Matrix as an Adobe.pdf file. EMC host connectivity guides (EMC storage systems only) The EMC host connectivity guides describe the features and setup procedures for host interfaces to EMC Symmetrix and CLARiiON systems. Host connectivity guides are updated quarterly and are published on the Powerlink website. EMC PowerPath for Linux Version 4.3 Release Notes 5

6 Environment and System Requirements Consult the EMC Support Matrix (and, for CLARiiON or Symmetrix systems, the EMC host connectivity guide for your operating system) before you install PowerPath. In addition, since changing any system component can change the way PowerPath manages storage paths, you should consult these resources before you undertake any of the following common system or network management tasks: Upgrade or change the host OS, or the host bus adapter. (Refer specifically to the Application Software chapter for your storage system model.) Change the model of the system that hosts PowerPath. Change or replace a host bus adapter type, or adapter cable on the system that hosts PowerPath. Change components (for example, switches) of your network configuration. Change the storage network zoning or device assignments. Change the array or storage system connected to the host. The information in the following sections is accurate at the time of publication. However, information about qualified hardware and software is revised and published monthly in the EMC Support Matrix and quarterly in the EMC host connectivity guides. In the event of discrepancies, information in the EMC Support Matrix or host connectivity guide for your platform takes precedence over the information in these sections. 6 EMC PowerPath for Linux Version 4.3 Release Notes

7 Environment and System Requirements Host Requirements Table 1 shows the requirements for Linux hosts to run PowerPath 4.3.x for Linux. Always refer to the EMC Support Matrix for the latest host configuration requirements. Table 1 PowerPath Host Requirements Linux Distribution Processor Type/ Configuration Recommended Minimum Memory Kernel Configurations Free Disk Space RHEL 3.0 Update 4 Advanced Server, Enterprise Server, 32-bit a Pentium Pro, II, III, IV Uni-processor and multi-processor At least 2GB EL i686.config i686-smp.config i686.hugemem.config 120MB in the root partition RHEL 3.0 Update 4 Advanced Server IA64 b RHEL 3.0 Update 4 Advanced Server, Enterprise Server, EM64T b IA64 At least 2GB EL kernel ia64.config 120MB in the root partition EM64T At least 2GB EL kernel ia32e.config 120MB in the root partition RHEL 3.0 Update 4 Advanced Server, Enterprise Server, Opteron AMD64 b, c Opteron AMD64 At least 2GB EL kernel x86-64-smp. config 120MB in the root partition SuSE SLES 8.0 SP3 32-bit a Pentium Pro, II, III, IV Multi-processor At least 2GB i386/defconfig.smp4g i386/defconfig.smp 120MB in the root partition Asianux 1.0 MLES 3.0 Red Flag bit only c Pentium Pro, II, III, IV Multi-processor At least 2GB AX i686-smp.config i686.hugemem.config 120MB in the root partition a. Refer to Guidelines for iscsi Configurations on page 11 for special iscsi requirements. b. Supported with QLogic HBAs only. c. Not supported by PowerPath EMC PowerPath for Linux Version 4.3 Release Notes 7

8 Environment and System Requirements Supported HBAs and Drivers Always refer to the EMC Support Matrix for the latest supported HBAs and drivers. PowerPath 4.3.x for Linux has been tested and qualified for use with the HBA models shown in Table 2. Table 2 Supported HBAs Manufacturer Model Supported with Symmetrix Arrays Supported with CLARiiON Arrays Supported with IBM ESS Arrays Supported with Hitachi Lightning Arrays QLogic QLA2342, QLA2340, QLA2310 QLA2200, Emulex LP9002, LP9802/DC, LP1050/DC, LP101, LP10k/DC For HBA models supported with HP StorageWorks EMA, EVA, MA and xp arrays, contact your HP representative. HP requires installation of the Platform Kit on every host connected to these arrays. The Platform Kit contains the drivers that are supported with the array. You can down load the Platform Kit from the HP website. 8 EMC PowerPath for Linux Version 4.3 Release Notes

9 Environment and System Requirements PowerPath 4.3.x for Linux has been tested and qualified for use on Symmetrix and CLARiiON arrays with the HBA drivers shown in Table 3. Table 3 HBA Driver Requirements for Symmetrix and CLARiiON Arrays Linux Distribution QLogic HBA Driver Emulex HBA Driver RHEL 3.0 AS/ES 32-bit v , v v RHEL 3.0 AS IA64, RHEL 3.0 AS/ES EM64T RHEL 3.0 AS/ES AMD64 v , v Not supported SuSE SLES 8 SP3 32-bit v , v v Asianux 1.0 (Red Flag 4.1 and MLES 3.0) 32-bit v v PowerPath 4.3.x for Linux has been tested and qualified for use on third-party arrays with the HBA drivers shown in Table 4. Table 4 HBA Driver Requirements for Third-Party Arrays Linux Distribution RHEL 3.0 AS/ES 32-bit QLogic HBA Driver IBM ESS: v Hitachi Lightning: v HP StorageWorks xp and EVA: v a SuSE SLES 8 SP3 32-bit IBM ESS: v Hitachi Lightning: v HP StorageWorks xp and EVA: v a a. Indicates that testing was done with HP-specific QLogic HBAs (FC2214/FC2214DC). For the HBA drivers supported with third-party arrays, contact the company s representative or download the latest driver from their website. If HBA drivers other than the QLogic qla2300 driver are used for StorageWorks EVA, EMA, or MA devices, expect unnecessary reassignments at times (for example, at boot time). Consequently, PowerPath cannot guarantee that the current owner remains the same after a reboot. Unnecessary reassignments can destroy non-persistent snaps on HSG80 based arrays (MA8000, EMA12000, and EMA16000). EMC PowerPath for Linux Version 4.3 Release Notes 9

10 Environment and System Requirements Storage System Configuration Symmetrix Storage Systems Refer to the EMC host connectivity guide for your operating system for information on setting up connections for Symmetrix and CLARiiON systems. For information on setting up connections for third-party storage systems, refer to your vendor s documentation. The following table shows requirements and specifications for a PowerPath host connected to a Symmetrix system. Make Model Microcode Versions Tested Paths per Device Symmetrix DMX series 5x69, 5x series 5x65, 5x66, 5x67, 5x68 Once a host and Symmetrix system are properly configured, you can install or upgrade PowerPath. See the PowerPath for Linux Installation Guide, P/N , for installation details. CLARiiON Storage Systems PowerPath is supported on CLARiiON FC-, CX-, and AX-series storage systems. Refer to the EMC Support Matrix and CLARiiON release notes for details. To properly install PowerPath on a host with a CLARiiON CX- or FC-series array, refer to the EMC Installation Roadmap for CX-Series and FC-Series Storage Systems. There you will find step-by-step instructions for installing PowerPath and other CLARiiON software. To obtain the latest versions of CLARiiON CX-series and FC-series documentation, log in to the Powerlink website ( CLARiiON AX100-series installation, planning, and troubleshooting documents are located on the AX100 support website. For information on accessing the site, refer to the support documentation that shipped with your storage system. Refer only to these documents for prescribed installation information when using AX100-series storage systems. 10 EMC PowerPath for Linux Version 4.3 Release Notes

11 Environment and System Requirements Supported Flare Revisions The following table lists the minimum FLARE revisions supported by PowerPath for Linux. CLARiiON Storage System Minimum Supported FLARE Revision Paths per Device AX CX300i CX500i CX200 CX300 CX400 CX500 CX600 CX FC Guidelines for iscsi Configurations The following guidelines apply to using Symmetrix and CLARiiON iscsi arrays with PowerPath. Supported Linux Distributions PowerPath supports iscsi arrays on RHEL3 U5 and SLES8 SP4, as shown in the following table. Linux Distribution Processor Type/ Configuration Recommended Minimum Memory Kernel Configurations Free Disk Space RHEL 3.0 Update 5 Advanced Server, Enterprise Server, 32-bit Pentium Pro, II, III, IV Uni-processor and multi-processor At least 2 GB EL i686.config i686-smp.config i686.hugemem.config 120MB in the root partition SuSE SLES 8.0 SP4 32-bit Pentium Pro, II, III, IV Multi-processor At least 2 GB i386/defconfig.smp4g i386/defconfig.smp 120MB in the root partition iscsi Devices Only The PowerPath host can only attach to iscsi devices. The host cannot attach to both Fibre Channel and iscsi devices. EMC PowerPath for Linux Version 4.3 Release Notes 11

12 Environment and System Requirements PowerPath Scripts Required for iscsi Support Before running PowerPath on a host connected to an iscsi array, you must download and run the follwing scripts: iscsi_script.sh, which allows a PowerPath host connected to iscsi devices to shut down and reboot without hanging (OPT ). emcp_delayconfig, which delays the execution of the powermt config command during system startup until after the iscsi session has been established (OPT ). You can download these scripts from the Powerlink web site: > Support > Downloads and Patches > Downloads D-R > PowerPath for Linux > PowerPath for Linux Patches Refer to Installing PowerPath on a Host Connected to iscsi Devices on page 22 for more information. iscsi Documentation Refer to the following documents for information on configuring iscsi arrays: EMC Linux iscsi Attach Release Notes, P/N EMC CLARiiON CX300, CX500, CX500i, and CX700 Storage Systems Configuration Planning Guide, P/N Revision A04 (or higher) EMC CLARiiON CX400 and CX600 Storage Systems Configuration Planning Guide, P/N Revision A06 (or higher) EMC CLARiiON CX200-Series Configuration Planning Guide, P/N Revision A04 (or higher) Planning Your AX100-Series iscsi Storage-System Configuration, P/N Revision A01 12 EMC PowerPath for Linux Version 4.3 Release Notes

13 Environment and System Requirements IBM ESS Storage Systems The following table shows the requirements and specifications for a PowerPath host connected to an IBM ESS system. Make Model Array Code/Firmware Required Maximum Paths per Device IBM F10/F /800T Once a host and IBM ESS system are properly configured, you can install or upgrade PowerPath. See the PowerPath for Linux Installation Guide, P/N , for installation details. Hitachi Lightning Storage Systems The following table shows the requirements and specifications for a PowerPath host connected to a Hitachi Lightning system. Make Model Qualified Array Code/Firmware Maximum Paths per Device Hitachi 9970V/9980V (or higher) / (or higher) Once a host and Hitachi Lightning system are properly configured, you can install or upgrade PowerPath. See the PowerPath for Linux Installation Guide, P/N , for installation details. Hewlett-Packard StorageWorks Systems The following table shows the requirements and specifications for a PowerPath host connected to an HP StorageWorks system. Make Model Minimum Array Code/Firmware Required Maximum Paths per Device HP HP StorageWorks Disk Array xp 128/1024 HP StorageWorks Disk Array xp 48/512 HP StorageWorks Enterprise Virtual Array (EVA) 3000/ VCS3.0, EMC PowerPath for Linux Version 4.3 Release Notes 13

14 Environment and System Requirements Once a host and HP StorageWorks system are properly configured, you can install or upgrade PowerPath. See the PowerPath for Linux Installation Guide, P/N , for installation details. Connectivity Requirements Refer to the EMC Support Matrix for information about the requirements for Fibre Channel and switched fabric configurations and components that can be used with PowerPath. Install HBAs, supported firmware versions, and other network components using the manufacturer s directions and the settings specified in the EMC Support Matrix. Using improper settings can cause erratic failover behavior or extended response time for system I/O. File System Support Table 5 Table 5 displays the file systems supported by PowerPath. File System Support Platform File System ext2 ext3 Reiserfs RHEL 3.0 SuSE SLES 8.0 SP3 Asianux 1.0 (Red Flag 4.1 and MLES 3.0) 32-bit 14 EMC PowerPath for Linux Version 4.3 Release Notes

15 Environment and System Requirements Volume Manager Support PowerPath for Linux supports the Sistina Linux Volume Manager (LVM) on the RHEL 3.0 and SuSE SLES 8 SP3 platforms. However, please note: EMC pseudo devices are not supported with the LVM. Instead, native SCSI devices must be used. Exercise care when selecting which native devices will be used. Only use a single device corresponding to a physical LUN. Data inconsistency may occur if multiple devices corresponding to the same physical LUN are used as separate LVM physical volumes. EMC recommends using the LVM CLI (Command Line Interface) instead of the LVM GUI (Graphical User Interface) to manage the Logical Volume environment. PowerPath only: Unmount any mounted Sistina volume before installing PowerPath PowerPath installation fails if it detects an active Sistina volume. During PowerPath installation, the PowerPath install script attempts to deactivate (and later activate) Sistina volumes. The install script will not be able to deactivate a volume if a file system is mounted on it. Therefore, any file system that needs to remain available during PowerPath startup (including file systems that store the operating system) cannot be mounted on a Sistina volume. Otherwise, PowerPath installation will fail. Cluster Support Refer to the EMC Support Matrix for the current information on cluster support. EMC PowerPath for Linux Version 4.3 Release Notes 15

16 Environment and System Requirements Interoperability Notes Take note of the following PowerPath interoperability issues. PowerPath and versions of Admsnap prior to PowerPath 4.3.x for Linux has the following interoperability problems with versions of Admsnap prior to These problems do not occur with Admsnap or higher. Upgrade to Admsnap or higher to avoid these issues. If you cannot upgrade to Admsnap or higher, take the following actions: Using PowerPath with a version of Admsnap prior to requires that you set the following two environment variables: PP_DEFAULT_STORAGE_SYS=clariion Setting this variable restricts the class of devices displayed by the powermt utility to CLARiiON devices, which prevents the display of extraneous third party array data from breaking versions of Admsnap prior to PP_SHOW_CLAR_OWNING_SP=false admsnap Setting this variable suppresses the display of line containing default and current SP data, which breaks versions of Admsnap prior to When using a version of Admsnap prior to , you must use a native PowerPath name (for example: /dev/sde) to start/activate an Admsnap session when a file system is mounted on the device. You cannot use a PowerPath pseudo device name (for example: /dev/emcpowere) to start/activate a session when a file system is mounted on that device. 16 EMC PowerPath for Linux Version 4.3 Release Notes

17 Known Problems and Limitations Known Problems and Limitations This section describes the known problems and limitations in PowerPath 4.3.x for Linux. Known Problems Version The known problems are listed below. Unless noted otherwise, problems apply to all Linux platforms. The following problems have been reported for PowerPath for Linux. Table 6 Known Problems in PowerPath Description PowerPath fails to uninstall when a Sistina logical volume is configured on a PowerPath-managed device Running the powermt remove dev=all command followed by the powermt config command causes misleading messages to be written to the system log Upgrading from RHEL 3.0 Update 3 to Update 4 on an IA64 host with either PowerPath or installed causes a system panic. This is a known problem in the IA64 RHEL 3.0 U4 kernel (RedHat Bugzilla # ) Running the powermt command or stopping and starting PowerPath scripts on an IA64 host with RHEL 3.0 U3 or U4 installed generates unexpected messages in the /var/log/messages file Setting an invalid policy on a specific CLARiiON device (either pseudo or native) returns an unexpected error message: Error: device(s) not found A host without a PowerPath license has a file system mounted on a PowerPath pseudo device. Attempting to remove PowerPath without first having unmounted the file system prevents PowerPath from being removed on the host. Workaround Run the following command to uninstall PowerPath: /etc/init.d/powerpath stop rpm -e EMCpower.LINUX Ignore the messages. To avoid the panic, you can: remove the /dev/emcpower file before booting the U4 kernel. remove the naviagent package before booting the U4 kernel. None. None. Install the licensed version of PowerPath. EMC PowerPath for Linux Version 4.3 Release Notes 17

18 Known Problems and Limitations Table 6 Known Problems in PowerPath (continued) Description If a snap session dies, the snap LU s state is set to inactive and I/O fails, as expected. The powermt display dev command, however, shows the paths to the snap LU as alive, and subsequent powermt commands hang Pulling and then reinserting CLARiiON disks with active I/O causes an unnecessary trepass to the default storage processor A host without a PowerPath license is connected to a CLARiiON array. After a LUN trepass occurs, running the powermt display dev command may show incorrect information about the device mode, with unlicensed paths shown as licensed Attempting to create a file system on a PowerPath pseudo device partition (for example, /dev/emcpowera1) fails. This occurs only on Symmetrix devices Specifying a PowerPath device when using the Database Configuration Assistant to choose the Automated Storage Management (ASM) option while creating an Oracle database causes the system to panic. Workaround None. None. Install the licensed version of PowerPath. Install the licensed version of PowerPath. None. Version The following problems have been reported for PowerPath for Linux. Table 7 Known Problems in PowerPath Description The PowerPath install script checks for /etc/miraclelinux-release instead of checking for /etc/asianux-release PowerPath hangs during reboot if there is a tape in the mouth of the tape drive and the tape door open Changes made to the sg driver code in RHEL 3 Update 4 breaks PowerPath functionality. Workaround/Resolution Resolved in Resolved in Resolved in EMC PowerPath for Linux Version 4.3 Release Notes

19 Known Problems and Limitations Table 7 Known Problems in PowerPath (continued) Description Running the powermt load command after the powermt remove dev=all command does not configure PowerPath devices Unable to unload or remove PowerPath after removing a PowerPath-managed native device file (that is, /dev/sd[a-z][a-z]) Installing PowerPath on a SuSE SLES 8.0 host connected to a CLARiiON storage system may cause unnecessary trespasses. Workaround/Resolution Run the following commands to configure PowerPath devices: powermt config powermt load Use the mknod command to recreate that native device file with its default major/minor numbers before trying to unload or uninstall PowerPath. Before installing PowerPath, run the following command to disable hardware scanning: /etc/init.d/hwscan stop Version The following problems have been reported for PowerPath for Linux. Table 8 Known Problems in PowerPath Description , PowerPath installation fails on RHEL 3.0 AS/ES IA64 Update 3 systems On a SuSE host, PowerPath pseudo (emcpower) devices may not be mounted or fsck'd appropriately at system boot Stopping and then restarting PowerPath on an RHEL 3.0 EM64T host without rebooting generates a series of warning messages about duplicate IOCTL registrations. No adverse affects other than the log messages have been observed. Workaround/Resolution Complete the following steps to install PowerPath on a RHEL 3.0 AS/ES IA64 system: 1. mkdir /emul/ia32-linux/bin 2. cp /bin/sh /emul/ia32-linux/bin/sh 3. ln -s /emul/ia32-linux /emul/ia32-linux 4. rpm -ivh --prefix / EMCpower.LINUX <buildnumber>.rpm Resolved in PowerPath None. EMC PowerPath for Linux Version 4.3 Release Notes 19

20 Known Problems and Limitations Table 8 Known Problems in PowerPath (continued) Description On a host with a CLARiiON Restricted license, PowerPath installation sets the default policy for CLARiiON AX100i devices to bf (basic failover) rather than to co (CLARiiON optimization) When an I/O operation is attempted on a protected by PowerPath Celerra device, the No such device or address error is returned The powermt display unmanaged command reconfigures paths that have been removed with the powermt remove command The powermt manage class command may return an initialization error if multiple instances of the command are running simultaneously Opening either a block or character SCSI disk path device file may cause PowerPath to configure that SCSI disk path for multipathing. Examples of Linux commands that open SCSI disk path device files include sg_map and blockdev. Workaround/Resolution Resolved in PowerPath None. None. Restart the powermt manage class command. None. 20 EMC PowerPath for Linux Version 4.3 Release Notes

21 Known Problems and Limitations Limitations PowerPath 4.3.0/4.3.1 This section describes the limitations in PowerPath 4.3.x. PowerPath 4.3.0/4.3.1 for Linux has the following limitations: PowerPath 4.3.0/4.31 for Linux do not support: United Linux. IA64 with 32-bit operating systems. More than 256 SCSI LUNS (paths) attached to a host. Placing the root or boot volume under PowerPath control. I/O rerouting from passive to active CLARiiON paths (first path policy on VxVM). Write throttling. PowerPath 4.3.0/4.3.1 is not interoperable with the following software products: VERITAS Volume Manager, Foundation Suite, and DMP VMWare ESX Server Egenera BladeFrame OS MPAA or MPAP storage device native multipathing (HP SecurePath, IBM SDD on Linux) PowerPath 4.3.0/4.3.1 load balancing does not work correctly for any application that uses SCSI-3 persistent register/reserve/preempt (for example: VCS DB/AC) with third-party storage systems. PowerPath PowerPath for Linux do not support: Asianux Linux (Red Flag or Miracle Linux). EMC PowerPath for Linux Version 4.3 Release Notes 21

22 Installation Installation Refer to the PowerPath for Linux Installation Guide, P/N , for complete instructions on installing PowerPath. First-time Installation Follow the instructions in the section entitled Installing PowerPath in Chapter 1, Installing PowerPath, of the PowerPath for Linux Installation Guide, P/N Upgrading from a Previous Revision Follow the instructions in the section entitled Upgrading PowerPath in Chapter 1, Installing PowerPath, of PowerPath for Linux Installation Guide, P/N Installing PowerPath on a Host Connected to iscsi Devices If you are installing PowerPath on a host connected to a Symmetrix or CLARiiON iscsi array, you must perform several additional steps after installing PowerPath. To install PowerPath on a host connected to an iscsi array: 1. Install PowerPath following the instructions in the PowerPath for Linux Installation Guide, P/N Download the iscsi_script.sh and emcp_delayconfig scripts from the Powerlink web site to the /etc/emc directory on the host. Follow this path to access these scripts on Powerlink: > Support > Downloads and Patches > Downloads D-R > PowerPath for Linux > PowerPath for Linux Patches 3. Run the iscsi_script.sh script. Enter: iscsi_script.sh install 4. Run the emcp_delayconfig script. Enter: emcp_delayconfig add <delay_in_seconds> where <delay_in_seconds> is the number of seconds to delay the execution of the powermt config command, allowing the iscsi session to become established. The default is 120 seconds. 5. Reboot the host. 22 EMC PowerPath for Linux Version 4.3 Release Notes

23 Documentation Documentation This section provides a list of the documentation that supports PowerPath for Linux. PowerPath Documentation The following table lists the PowerPath for Linux documentation set; all manuals are available from EMC Corporation. Part Number Name PowerPath Product Guide PowerPath for Linux Installation Guide PowerPath Quick Reference PowerPath for Linux Release Notes Electronic versions of all PowerPath manuals are available on the Powerlink website These manuals are updated periodically. Related Documentation If your environment includes Symmetrix storage systems, refer also to the EMC host connectivity guides, which are available on the Powerlink website. If your environment includes CLARiiON storage systems, refer also to the following manuals: EMC host connectivity guides EMC Installation Roadmap for CX-Series and FC-Series Storage Systems. To obtain the latest versions of CLARiiON CX-series and FC-series documentation, log in to the Powerlink website. CLARiiON AX100-Series installation, planning, and troubleshooting documents, located on the AX100 support website. For information on accessing the site, refer to the support documentation that shipped with your storage system. Refer only to these documents for prescribed installation information when using AX100-Series storage systems. EMC Navisphere Manager Version 6.X Administrator s Guide If your environment includes other vendors storage systems, refer to the appropriate documentation from your vendor. EMC PowerPath for Linux Version 4.3 Release Notes 23

24 Software Media, Organization, and Files Software Media, Organization, and Files This section describes the contents of the PowerPath for Linux CD. Media The PowerPath for Linux software is distributed on a CD, P/N Organization The PowerPath for Linux CD contains the following rpm package: /LINUX/EMCpower.LINUX rpm Troubleshooting and Getting Help For additional information on EMC products and services available to customers and partners, refer to the EMC Powerlink website If you find a problem in PowerPath 4.3, run the emcgrab utility, and submit the generated tar file, along with any other supporting material, to EMC Customer Support. You can download emcgrab from the Powerlink website. 24 EMC PowerPath for Linux Version 4.3 Release Notes

25 Troubleshooting and Getting Help EMC PowerPath for Linux Version 4.3 Release Notes 25

26 Troubleshooting and Getting Help Copyright EMC Corporation. All rights reserved. EMC believes the information in this publication is accurate as of its publication date. The information is subject to change without notice. THE INFORMATION IN THIS PUBLICATION IS PROVIDED "AS IS." EMC CORPORATION MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WITH RESPECT TO THE INFORMATION IN THIS PUBLICATION, AND SPECIFICALLY DISCLAIMS IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Use, copying, and distribution of any EMC software described in this publication requires an applicable software license. Trademark Information 26 EMC PowerPath for Linux Version 4.3 Release Notes