300-002-581

These release notes contain information about features, system requirements, and limitations of PowerPath 4.4.x for Linux.

◆ PowerPath Support for Linux 2.6 and 2.4 Kernels ...........................2◆ New Features and Changes .................................................................2◆ Environment and System Requirements .......................................... 4◆ Known Problems and Limitations ................................................... 12◆ Installation Notes ............................................................................... 16◆ Technical Notes ................................................................................... 17◆ Documentation ....................................................................................21◆ Troubleshooting and Getting Help ...................................................22

EMC PowerPathfor Linux

Version 4.4 and Point Releases

Release NotesP/N 300-002-581

Rev A04

February 17, 2006

1

2

PowerPath Support for Linux 2.6 and 2.4 Kernels

PowerPath Support for Linux 2.6 and 2.4 KernelsEMC® PowerPath® 4.4 and higher only support the Linux 2.6 kernel. PowerPath 4.3.x only supports the Linux 2.4 kernel.

◆ If you run the RHEL 4.0, Asianux 2.0, or SLES 9.0 operating systems, you must use PowerPath 4.4 or higher.

Note: Upgrades from PowerPath 4.3.x to PowerPath 4.4 or higher require Linux 2.6 kernel upgrades.

Refer to “Environment and System Requirements” on page 4 for more kernel-specific information.

◆ RHEL 3.0, SLES 8, Asianux 1.0, United Linux, and Miracle Linux are currently available for the Linux 2.4 kernel, which requires PowerPath 4.3.x.

Refer to Environment and System Requirements in the PowerPath 4.3 and Point Releases for Linux Release Notes for more kernel-specific information.

New Features and ChangesPowerPath 4.4.x provides the following new features and changes.

PowerPath 4.4.1 New FeaturesPowerPath 4.4.1 provides the fixes in “Known Problems” on page 13.

Changed BehaviorThe Symmetrix Optimized (for Symmetrix), CLARiiON Optimized (for CLARiiON), and Adaptive (for active-active third-party arrays) policies has been optimized for PowerPath 4.4.1. (The Adaptive policy remains unchanged for active-passive third-party arrays). These optimized policies provide better sequential I/O performance by switching paths after sending 1000 I/Os down a single path. By default, these optimized policies are in effect after PowerPath 4.4.1 installation.

EMC recommends that you use the optimized versions of the Symmetrix Optimized, CLARiiON Optimized, and Adaptive policies. You can, however, revert to the non-optimized versions of these policies. A /proc interface called IO_threshold lets you switch between the optimized and non-optimized versions. By default, the

EMC PowerPath for Linux Version 4.4 and Point Releases Release Notes

New Features and Changes

IO_threshold value is set to 1000 during PowerPath 4.4.1 installation, which indicates that 1000 I/Os are sent down a path before switching paths (the optimized behavior).

To revert to the non-optimized behavior, enter:

echo "IO_threshold 0" >/proc/emcp/emcp2

To switch to the optimized behavior, enter:

echo "IO_threshold 1000" >/proc/emcp/emcp2

Note: 1000 and 0 are the only supported values for the IO_threshold variable.

PowerPath 4.4.0 New FeaturesPowerPath 4.4.0 for Linux provides the following new features:

◆ Support for the Linux 2.6 kernel. Specifically, PowerPath 4.4.0 for Linux supports SuSE Linux Enterprise Server (SLES) 9.0 SP1 32-bit and 64-bit systems, and Red Hat Enterprise Linux (RHEL) Advanced Server/Enterprise Server (AS/ES) 4.0 32-bit and 64-bit systems.

◆ Full functionality on hosts connected to CLARiiON AX 100-series arrays with or without a PowerPath license.

◆ Sistina Logical Volume Manager 2 (LVM2) on SLES 9 and RHEL 4.0.

Note: On RHEL 4.0, PowerPath 4.4.0 requires LVM2 version v2.01.08-1.0 or higher due to Bugzilla #151657.

Changed BehaviorsThe following behavior has changed from PowerPath 4.3.x for Linux to PowerPath 4.4.0:

◆ The Linux iostat command no longer displays I/O statistics for EMC pseudo devices.

◆ PowerPath binaries are no longer built with modversioning disabled. All PowerPath binaries are built with modversioning enabled.

◆ Multipathing services are no longer provided for character I/O initiated on native sg devices such as /dev/sg0. In addition, multipathing services are not provided for SCSI command pass

EMC PowerPath for Linux Version 4.4 and Point Releases Release Notes 3

4

Environment and System Requirements

through I/O issued to the block interface using ioctl(2) system calls and passing the commands SG_IO or SCSI_IOCTL_SEND_COMMAND.

Environment and System RequirementsPowerPath host-based software operates on the Red Hat Enterprise Linux 4.0 and SuSE Linux Enterprise Server 9 SP1 operating systems with Symmetrix®, CLARiiON®, IBM ESS, Hitachi Lightning, and HP StorageWorks xp, EVA, EMA, and MA storage systems.

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 is updated every month and published on the Powerlink™ website at http://Powerlink.EMC.com.

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.


http://powerlink.emc.com


◆ 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.

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


Host Requirements Table 1 shows the minimum requirements for Linux hosts to run PowerPath 4.4.x for Linux. EMC recommends that all hosts have at least 2 GB of memory and 120 MB of free disk space in the root partition.

Note: Refer to the EMC Support Matrix for the latest host configuration requirements. Information in the EMC Support Matrix supersedes the following information.

Table 1 PowerPath Host Requirements

Linux DistributionProcessor Type/Configuration Kernel Configurations

RHEL 4.0 AS/ES, 32-bit Pentium Pro, II, III, IVUni-processor

2.6.9-5.EL2.6.9-5.0.5EL

configs/i686.config

RHEL 4.0 AS/ES, 32-bit Pentium Pro, II, III, IVMulti-processor

2.6.9-5.EL2.6.9-5.0.5EL

configs/i686-smp.config

RHEL 4.0 AS/ES IA64a IA64 2.6.9-5.EL2.6.9-5.0.5EL

configs/ia64.config

RHEL 4.0 AS/ESEM64T, Opteron AMD64

EM64T, Opteron AMD64

2.6.9-5.EL2.6.9-5.0.5EL

configs/x86_64-smp.config

SLES 9.0 SP 1 32-bit Pentium Pro, II, III, IVUni-processor

2.6.5-7.151 i686/defconfig

SLES 9.0 SP 1 32-bit Pentium Pro, II, III, IVMulti-processor

2.6.5-7.151 i686/defconfig.bigsmp

SLES 9.0.SP1 IA64a IA64 2.6.5-7.151 ia64/defconfig

SLES 9.0 SP1 EM64T, Opteron AMD64

EM64T, Opteron AMD64

2.6.5-7.151 x86_64/defconfig.smp

a. Not supported in PowerPath 4.4.1.



Supported HBAsand Drivers

Note: Refer to the EMC Support Matrix for the latest HBA and driver requirements. Information in the EMC Support Matrix supersedes the following information.

PowerPath 4.4.x for Linux has been tested and qualified for use on Symmetrix and CLARiiON arrays with the HBA drivers shown in Table 2 below.

PowerPath 4.4.x for Linux has been tested and qualified for use on third-party arrays with the HBA drivers shown in Table 3.

Table 2 HBA Driver Requirements for Symmetrix and CLARiiON Array

Linux Distribution QLogic HBA Driver Emulex HBA Driver

RHEL 4.0 AS/ES 32-bitRHEL 4.0 AS IA64,RHEL 4.0 AS/ES EM64TRHEL 4.0 AS/ES AMD64

8.00.03a 8.0.16.6_x2

SLES 9 SP1 32-bitSLES 9 SP1 IA64,SLES 9 SP1 EM64TSLES 9 SP1 AMD64

8.00.03b 8.0.16.6_x2

a. On RHEL 4.0, set both the ConfigRequired and ql2xfailover parameters to 0 in the /etc/modprode.conf file, and then rebuild the RAM disk.

b. On SLES 9 SP1, set both the ConfigRequired and ql2xfailover parameters to 0 in the /etc/modprode.conf.local file, and then rebuild the RAM disk.

Table 3 HBA Driver Requirements for Third-Party Arrays

Linux Distribution QLogic HBA Driver

RHEL 4.0 AS/ES 32-bitRHEL 4.0 AS/ES 64-bit

IBM ESS: 8.00.03a

Hitachi Lightning: 8.00.03a, b

HP StorageWorks xp and EVA: 8.00.03a

SLES 9 SP1 32-bitSLES 9 SP1 64-bit

IBM ESS: 8.00.03c

Hitachi Lightning: 8.00.03b, c

HP StorageWorks xp and EVA: 8.00.03c

a. On RHEL 4.0, set the ConfigRequired parameter to 0 in the /etc/modprode.conf file, and then rebuild the RAM disk.

b. Hitachi Lightning arrays are only supported on the 32-bit versions of RHEL 4.0 and SLES 9.0 SP1.

c. On SLES 9, set the ConfigRequired parameter to 0 in the /etc/modprode.conf.local file, and then rebuild the RAM disk.


8


Note: For the HBA drivers supported with third-party arrays, contact the company’s representative or download the latest driver from their website.

Note: 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).

Storage SystemConfiguration

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.

Note: Refer to the EMC Support Matrix for the latest storage system requirements. Information in the EMC Support Matrix supersedes the following information.

Symmetrix StorageSystems

PowerPath 4.4.x supports the following Symmetrix systems.

Make ModelMicrocode Versions Tested Paths per Device

Symmetrix DMX series 5x69, 5x70, 5x71 32

8000 series 5x67, 5x68



CLARiiON StorageSystems

PowerPath 4.4.x supports the following CLARiiON CX-series 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-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. The latest versions of CLARiiON CX-series documentation are available the Powerlink website at http://Powerlink.EMC.com.

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.

IBM ESS StorageSystems

PowerPath 4.4.x supports the following IBM ESS systems.

Make ModelMinimum SupportedFLARE Revision

Paths per Device

CLARiiON AX100AX100SC

02.08 32

CX200CX300CX400CX500CX600CX700

02.07

Make ModelArray Code/FirmwareRequired

Maximum Paths per Device

IBM 2105 F10/F20 2.2.0.593 32

800/800T 2.3.0.465



10


Hitachi LightningStorage Systems

PowerPath 4.4.x supports the following Hitachi Lightning systems.

Note: Hitachi Lightning arrays are only supported on the 32-bit versions of RHEL 4.0 and SLES 9.0 SP1.

Hewlett-PackardStorageWorks Systems

PowerPath 4.4.x supports the following HP StorageWorks systems.

Make ModelQualified Array Code/Firmware


Hitachi 9970V/9980V 21-05-27 (or higher) 32

9910/9960 01-19-26 (or higher)

Make Model

Minimum Array Code/FirmwareRequired


HP HP StorageWorks Disk Array xp 128/1024

21-05-27 32

HP StorageWorks Disk Array xp 48/512

01-17-26

HP StorageWorks EVA 3000/5000a

VCS3.0, 3.010

HP StorageWorksEMA 12000/16000

HP StorageWorksMA 8000

a. PowerPath does not support HP StorageWorks EVA 3000/5000 storage systems with firmware revision 4.001or higher.



ConnectivityRequirements

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.

Note: 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 4 displays the file systems supported by PowerPath.

Sistina LVM2 PowerPath 4.4.x for Linux supports the Sistina LVM2 on the RHEL 4.0 and SLES 9 SP1 platforms. PowerPath supports the creation of logical volumes on PowerPath pseudo devices only.

Note: On RHEL 4.0, PowerPath 4.4.x requires LVM2 version v2.01.08-1.0 or higher due to Bugzilla #151657.

Refer to “Configuring LVM2 Support” on page 17 for instructions on configuring LVM2 support for PowerPath.

Cluster Support Refer to the EMC Support Matrix for the current information on cluster support.

Table 4 File System Support

PlatformFile System

ext2 ext3 Reiserfs XFS

RHEL 4.0 ✔ ✔

SLES 9.0 SP1 ✔ ✔ ✔ ✔


12

Known Problems and Limitations

Known Problems and LimitationsThis section describes the fixed problems, known problems, and limitations in PowerPath 4.4.x for Linux.

Fixed Problems The following problems are fixed in PowerPath 4.4.1 for Linux.

Table 5 Resolved Problems in PowerPath 4.4.1

DescriptionFound inVersion

Fixed in Version

228720Starting PowerPath on a host on which a USB disk device has been inserted and removed several times causes the host to panic.

4.4.0 4.4.1

227526With PowerPath loaded, the partitions on a SanDisk are not created during boot.

4.4.0 4.4.1

226996PowerPath does not restore paths after an SP reboot. The powermt restore command hangs.

4.4.0 4.4.1

223897The pseudo device partition table is not is sync with the native device partition table.

4.4.0 4.4.1

221248Sequential I/O performance degrades on a host with PowerPath installed.

4.4.0 4.4.1



Known Problems The following problems have been reported for PowerPath 4.4.x for Linux.

Table 6 Known Problems in PowerPath 4.4.x

Description Workaround

229247The PowerPath deinstallation program returns the following error when it detects that the powermt command is running:PowerPath could not unload module emcp

Deinstallation continues, instead of stopping as it should. Subsequent attempts to install PowerPath fail with the following message:Cannot load PowerPath drivers because at least one driver is already loaded.

1. Run the lsmod | grep emcp command to see the loaded PowerPath modules.

2. Use the rmmod command to remove each of the loaded PowerPath modules.

3. Install PowerPath.

228265Trespass failed messages are written to the /var/log/messages file during an NDU revert operation when the primary SP reboots.

The message can safely be ignored.

228404On a SLES9 SP1 host with Emulex HBAs, stopping and restarting PowerPath after running the powermt remove dev=all commands causes the LUNs to trespass.

Run the powermt restore command to trespass the LUNs to their default owner.

228321PowerPath start service fails if the umount -a command is executed on RHEL4 to unmount the devices before stopping the PowerPath service.

See Bugzilla #177523.

228005When I/O is running to a native device, the powermt display command displays conflicting output for the queued I/O on a path and total queued I/O.

None.

227921Upgrading from PowerPath 4.4.0 to PowerPath 4.4.1 on a host on which an USB disk has repeatedly removed and reinserted causes a panic.

1. Remove the USB disk.2. Reboot the host.3. Upgrade to PowerPath 4.4.1.

227735The powermt restore command does not restore all paths after reconnecting SP cables. Device remains in the offline state.

1. Manually change the state of the target device.2. Rerun the powermt restore command.

227570The PowerPath uninstall program does not remove “emcpower” files from the /dev directory.

Remove the files manually.


14


216862After upgrading a RHEL host with PowerPath 4.4 installed to RHEL 4.0 Update 1, running the rpm command to refresh the PowerPath package fails.

Before refreshing the PowerPath package, create a directory named extra under /lib/modules/`uname -r` where PowerPath unloads its modules:mkdir /lib/modules/‘uname -r‘/extra

216584Using native device names to create a file system on a partition that was created using a PowerPath pseudo name returns the following error:Could not stat <device> --- No such file or directory

Run the blockdev --rereadpt <native_device> command to update the partition list, and then recreate the file system.

214659Symmir will not establish a BCV mirror using the PowerPath pseudo name of a Symmetrix metavolume.

Use the native volume name.

213948During PowerPath installation and whenever the powermt config command is run, the following message is logged for each new native device:kernel: Setting invalidated flag for dev <device#>

Ignore the message.

213242The powermt remove dev=all command removes an alive path if the last path to a device is dead that leads to filesystem corruption of emcpower devices.

Remove dead paths before executing the powermt remove dev=all commands using the following command sequence:powermt remove dev=<dead path>powermt remove dev=all

212513After installing PowerPath 4.4 on a RHEL 4.0 with Emulex HBAs, the following message is displayed during boot and no devices are visible:Unknown IOCB command Data

1. Uninstall PowerPath 4.4.2. Upgrade the HBA firmware to 3.92a2 (available on the

Emulex web site: http://emulex.com/ts/docoem/framemc.htm)

3. Reinstall PowerPath.

212189When you create a partition by running the fdisk command on a PowerPath pseudo device, the partition list in the /proc/partitions file does not get updated for the native device.

Run the fdisk command on a native device, which updates the /proc/partitions file for both the pseudo and native devices.If you have already run the fdisk command on a PowerPath pseudo device, run the blockdev --rereadpt <native_device> command to update the partition list.

Table 6 Known Problems in PowerPath 4.4.x (continued)




211765PowerPath uninstall fails on an SuSE9 SP1 host connected to Symmetrix devices.

Manually remove the PowerPath drivers and scripts.

212369A RHEL 4.0 host panicked during a repeated failover and restore sequence.

None.

212329PowerPath pseudo device names are not displayed on the Navisphere Manager even after starting Naviagent on the host.

None.

211431Manually editing the /etc/emc/mpaa.lams file (that is, for generic LAM support) to change the status of a LAM that has configured devices causes the powermt config command to return an error.

The error is benign; ignore it.

210689On a host with SLES9 and qla2300 adapters attached to a Symmetrix, paths that have no outside users (no volume manager, no I/O, only PowerPath internal activity), will fail by themselves approximately every 20 minutes.

Run the powermt restore command.

210522The PowerPath stop script and uninstall program (which calls the stop script) fail on a RHEL host with active LVM2 logical volumes.

Create the following link before stopping or uninstalling PowerPath:ln -s /usr/sbin/vgdisplay /sbin/vgdisplay

210320Restoring a path on a RHEL host with an Emulex HBA (for example, by disabling and then re-enabling the port on the switch) causes the host to crash.

Either reinstall RHEL 4.0, which has CONFIG_FRAME_POINTER undefined by default in a new installation, or recompile the kernel with CONFIG_FRAME_POINTER undefined.

209697Opening a native device succeeds with all paths are down, which prevents an application from detecting if the device is ready by sending an open and then a close.

None.

208594On SLES 9 hosts, the Naviagent CLI (version 6.17, 6.18, and 6.19 for the Linux 2.6 IA64 kernel) startup script fails when CLARiiON LUNs are attached to the host.

None.

206453, 206031PowerPath logs “dead path” messages even though no failure has occurred.

None.

Table 6 Known Problems in PowerPath 4.4.x (continued)



16

Installation Notes

Limitations PowerPath 4.4.x for Linux has the following limitations:

◆ PowerPath 4.4.1 does not support IA64 platforms.

◆ PowerPath 4.4.x for Linux does not support:

• RHEL 3.0, SLES 8, United Linux, Asianux Linux (Red Flag or Miracle Linux).

• IA64 with 32-bit operating systems.

• Booting from an external storage array.

• VERITAS Volume Manager (VxVM).

• Write throttling.

◆ PowerPath 4.4.x does not support Oracle ASMLib. Do not install Oracle ASMLib and PowerPath on the same host.

◆ PowerPath 4.4.x 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.

Installation NotesInstall PowerPath following the instructions in Chapter 1, “Installing PowerPath,” of the PowerPath 4.4 for Linux Installation Guide, P/N 300-002-580. Take note of the following issues before installing PowerPath.

Installing PowerPath on a RHEL Host with Emulex HBAsIf you plan to install PowerPath 4.4.x on a RHEL 4.0 host with Emulex HBAs, you must upgrade the HBA firmware to revision 3.92a2 (available on the Emulex web site, http://emulex.com/ts/docoem/framemc.htm) before installing PowerPath 4.4.x. If you do not upgrade the firmware, the following message is displayed during boot time and no storage devices will be visible:

Unknown IOCB command Data


Technical Notes

Technical NotesThis section contains additional information on PowerPath not covered in the core documents. This section describes:

◆ Installing QLogic qla2300 HBAs after PowerPath installation

◆ Configuring LVM2 support

Installing QLogic qla2300 HBAs after PowerPath InstallationIf you install QLogic qla2300 HBAs and drivers after PowerPath has been installed on a host connected to an HP StorageWorks EVA array, add the following lines to the /etc/modprobe.conf.pp file:

install qla2xxx /sbin/modprobe emcpsf;/sbin/modprobe qla2xxx --ignore-install install emcp /sbin/modprobe qla2xxx;/sbin/modprobe emcp --ignore-install

Configuring LVM2 SupportYou must modify the /etc/lvm/lvm.conf file to filter out sd device nodes from its internal cache so that LVM2 recognizes a PowerPath pseudo device as the single path to LUN. The following sections describe how to modify /etc/lvm/lvm.conf on a host where the root file system is:

◆ not mounted on a logical volume.

◆ is mounted on a logical volume.

◆ is mounted on mirrored logical volumes.

Root File System Not Mounted on a Logical VolumeModify the filters field of the /etc/lvm/lvm.conf file to prevent LVM2 from scanning sd device nodes.

1. Modify the filter field in the /etc/lvm/lvm.conf file. Replace:

filter=["a/.*/"]

with:

filter=["r/sd.*/", "a/.*/"]

2. Rebuild the LVM2 cache. Enter:

vgscan -v


18

Technical Notes

3. Verify that the filter field is working correctly. Run the command below and verify that the “filtered” device nodes are not listed in the command output. Enter:

lvmdiskscan

Root File System Mounted on a Logical VolumeIdentify the underlying device(s) for the root/swap logical volume(s) and the /boot devices (if any). Modify the filters field of the /etc/lvm/lvm.conf file to prevent LVM2 from scanning all sd device nodes except for root/swap and /boot device(s).

1. Identify the root/swap logical volume(s) and the /boot devices (if any). Enter:

df -k

or

mount

2. Identify the underlying device(s) for the root/swap logical volume(s). For example, if the root file system is mounted on logical volume /dev/vg01/lv01, enter:

vgdisplay -v /dev/vg01/lv01

3. Modify the filter field in the /etc/lvm/lvm.conf file to prevent LVM2 from scanning all sd device nodes except for root/swap and /boot devices identified in steps 1 and 2. For example, if the underlying device for the root/swap file system is /dev/sda2 and /boot is mounted on /dev/sda3, set the filter filter field to:

filter=["a/sda[1-9]$/", r/sd.*/", "a/.*/"]

Note: Modify the filter as needed using standard shell-scripting regular expressions. For example, to include partitions sda1 to sda9 for LVM2 while filtering out the remaining sd device nodes, set the filter field to filter=["a/sda[1-9]$/", "r/sd.*/", "a/.*/"].


vgscan -v


Technical Notes

5. Verify that the filter field is working correctly. Run the command below and verify that the sd device nodes containing the root/swap/boot devices identified in steps 1 and 2 are listed in the command output, and that the “filtered” device nodes are not listed in the command output. Enter:

lvmdiskscan

6. Recreate the initrd image to reflect the changes to the /etc/lvm/lvm.conf file. Enter:

mkinitrd

Root File System Mounted on Mirrored Logical VolumesIdentify the underlying device(s) for the root/swap logical volume(s) and the /boot devices (if any). Modify the filters field of the /etc/lvm/lvm.conf file to prevent LVM2 from scanning all sd device nodes except for root/swap and /boot device(s).

1. Identify the root/swap logical volume(s) and the /boot devices (if any). Enter:

df -k

or

mount

2. Identify the underlying device(s) for the root/swap and mirror logical volume(s). For example, if the root file system is mounted on logical volume /dev/vg01/lv01 and its mirror is mounted on /dev/vg01/lv02, enter:

vgdisplay -v /dev/vg01/lv01vgdisplay -v /dev/vg01/lv02

3. Modify the filter field in the /etc/lvm/lvm.conf file to prevent LVM2 from scanning all sd device nodes except for root/swap and /boot devices identified in steps 1 and 2. For example, if the underlying logical device for the root/swap file system is /dev/sda2 and its mirror is /dev/sdb3, set the filter field to:

filter=["a/sda[1-3]$/", "a/sdb[1-3]$/", "r/sd.*/", "a/.*/"]


20

Technical Notes

Note: Modify the filter as needed using standard shell-scripting regular expressions. For example, to include partitions sda1 to sda9 for LVM2 while filtering out the remaining sd device nodes, set the filter field to filter=["a/sda[1-9]$/", "r/sd.*/", "a/.*/"].


vgscan -v

5. Verify that the filter field is working correctly. Run the command below and verify that the sd device nodes containing the root/swap/boot devices identified in steps 1 and 2 are listed in the command output, and that the “filtered” device nodes are not listed in the command output. Enter:

lvmdiskscan

6. Recreate the initrd image to reflect the changes to the /etc/lvm/lvm.conf file. Enter:

mkinitrd


Documentation

DocumentationThis section provides a list of the documentation that supports PowerPath for Linux.

PowerPathDocumentation

The following table lists the PowerPath for Linux documentation set; all manuals are available from EMC Corporation.

Electronic versions of all PowerPath manuals are available on the Powerlink website at http://Powerlink.EMC.com. These manuals are updated periodically on the Powerlink website.

RelatedDocumentation

If your environment includes Symmetrix storage systems, refer to the EMC host connectivity guides, available on the Powerlink website.

If your environment includes CLARiiON storage systems, refer to the following manuals:

◆ EMC host connectivity guides

◆ EMC Installation Roadmap for CX-Series and FC-Series Storage Systems. The latest versions of CLARiiON CX-series documentation are available on 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.

Part Number Name

300-002-308 PowerPath Product Guide

300-002-310 PowerPath Quick Reference

300-002-580 PowerPath for Linux Installation Guide

300-002-581 PowerPath for Linux Release Notes



22

Troubleshooting and Getting Help

Troubleshooting and Getting HelpFor additional information on EMC products and services available to customers and partners, refer to the Powerlink website at http://Powerlink.EMC.com.

If you find a problem in PowerPath 4.4.x, 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


Copyright © 2006 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.

For the most up-to-date listing of EMC product names, see EMC Corporation Trademarks on EMC.com.

All other trademarks used herein are the property of their respective owners.


300-002-581

Documents

limitations of powerpath

powerpath binaries

kernelsemc powerpath

powerpath license

new features powerpath

kernels powerpath support

linux version

united linux