IBM AIX-AK FZK 2005 manual LUN Thrashing Scenario

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IBM Systems Group

LUN Thrashing Scenario

Linux host 1		Linux host 2
HBA 0	HBA 1	HBA 0	HBA 1

A DS4000 B

Disk

LUN 0

AIX-AK FZK 2005

© 2005 IBM Corporation

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Contents AIX AK April 2005 Forschungszentrum Karlsruhe IBM Storage with Linux Topics  What is supported What Is SupportedIBM Storage Support for Linux  DS6000, DS8000 SLES8, SLES9, RH-EL PLinux Support Disk DS4000 SLES8, SLES9, RH-EL  Parallel Scsi attachment also supported  Advanced PLinux Support Tape LTO Sles 8, Sles 9, RH-EL  359x Sles 8, Sles 9, RH-ELLinux Scsi Subsystem Everything is a file Linux Device AddressingUpper level DesignLinux Kernel Version Storage Changes in Linux Kernel Still there Wellknown Linux Scsi Limitations Multiple LUN support of RH-EL  DS4000 Specific Other Problems and Pitfalls ESS, DS6000, DS8000 Specific  Linux Kernel Limits Large filesystems supportMultipathing Scenarios Multipathing Concepts LUN Transfer to Alternate Controller  Two multipathing solutions available DS4000 transfers LUNs to alternate controller LUN Thrashing Scenario LUN Thrashing Scenario LUN Thrashing Scenario Multipathing with Rdac  Must run mppUpdate after each configuration changeRdac Shared Data Scenario Rdac Shared Data Scenario Rdac Shared Data Scenario  DS6000 uses concept of preferred path Preferred Path SDD knows preferred path automatically Preferred Path Shared Data Scenario Preferred Path Shared Data Scenario Preferred Path Shared Data Scenario Preferred Path Shared Data Scenario  ESS and DS8000 have independent host ports Host Ports Independent of ControllerIndependent Host Port Shared Data Scenario Independent Host Port Shared Data Scenario Independent Host Port Shared Data Scenario Tape Specifics  Daemon IBMtaped IBMtape driverIBMtapeUtil  Build and install using make  Provides For download as source code  Native Use LTO Devices 3rd party applications Native Library Management Medium Changer Failover One driver for all HBAs Tape and Disk Connected to the Same HBAQuestions & Discussion ESS / DS6000 / DS8000 Resources DS4000 Resources LTO Resources Redbooks White Papers Legal Notices