multipath设备删除失败处理思路（mapinuse）

　　问题：UnabletoremovethemultipathdeviceafterunmappingtheLUNfromtheserver。AttemptingtoflushamultipathmapwithmultipathformultipathFresultsinmapinusemultipathfmpath7mpath7：mapinuse
　　Themultipathcommandstillshowsthemultipathdevice，withpath（s）totheunmappedLUNasfollows：multipathllmpath7mpath7（36090a01870982994dcb8d4405ed03cbf）dm7，〔size4。4T〕〔features1queueifnopath〕〔hwhandler0〕〔rw〕roundrobin0〔prio0〕〔enabled〕：：：：〔failed〕〔faulty〕决议Locateanysubsystemorprocessholdingthemultipathdeviceopen。Seediagnosticstepsforpossibletoolsandtechniques。Foranysubsystemorprocessholdingthemultipathdeviceopen，stoptheprocess，orissuecommandstoreleasethemultipathdevice。Someexamplesofpossibleholdersofamultipathdeviceandthecommandstoreleaseit：
　　1、Afilesystemexistsonthemultipathdeviceandiscurrentlymounted。
　　Unmountthefilesystemandifitexistsinetcfstab，removeit。
　　2、Oneormorepartitionmapping（s）stillexistsonthemultipathdevice。
　　Usekpartxdonthemultipathdevicetoremovethedevicepartitionmapping（s）。
　　3、ThemultipathdevicewasusedbyLVM，andstillhasdevicemapperstateinthekernel。Uselvchangeantodeactivateanylogicalvolume（s）associatedwiththemultipathdevice。Alistoflogicalvolumesassociatedwiththemultipathdevicemaybefoundbyexaminingtheoutputoflvsodevices。Iflvchangeanfails，thelogicalvolumeisonlypartiallyremoved，orthereareblockedprocesseswithIOoutstandingonthedevice，usedmsetupremoveffollowedbydmsetupclearonthemultipathdevice。Seedmsetupmanpageforfullexplanationofthesecommands。
　　4、Onceallholdersofthedevicehavebeenremoved，themultipathdeviceshouldbeflushedwithmultipathf。
　　根源Themultipathdevicewasheldopenbyatleastoneprocessorsubsystem。
　　诊断步骤Uselsoftoattempttofindanyoneholdingthedeviceopen。CheckdmsetupoutputforanydevicemappermapsthatdependonthemultipathdeviceChecktheifthereisadeviceformpath7indevmappermpath7Checkmultipathv4ll