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If you want to use any other third party multipathing software apart from DM (Linux native multipathing) then to disable DM follow below steps: 1. Blacklist all devices in /etc/multipath.conf. Edit /etc/multipath.conf so that it contains only the following lines: blacklist { devnode "*" } 2. Ensure dm-multipath does not start automatically at boot. # systemctl disable multipathd.service # systemctl list-unit-files | grep multipath  multipathd.service                          disabled 3. Recreate initramfs so that dm-multipath is excluded from initramfs. # dracut /boot/initramfs-wo-DM-$(uname -r).img $(uname -r) Take a backup of existing /boot/initramfs-$(uname –r).img file and rename the above created initrmafs file to the name of orginal initramfs file. 4. Reboot the host with the new initramfs image and ensure dm-multipath does not have 5. To check if any devices are configured # multipa...

1. To check how many HBA's are installed and which are all having connectivity # esxcli storage core adapter list HBA Name  Driver      Link State  UID                                   Capabilities                         Description                                                     --------  ----------  ----------  ------------------------------------  -----------------------------------  --------------------------------------------------------------------------------------- vmhba0     hpdsa       link-n/a    unknown.vmhba0                      ...

LUN reset - Resets the specified LUN by clearing any SCSI reservation on the LUN and making the LUN available to all servers again. The reset does not affect any of the other LUNs on the device. If another LUN on the device is reserved, it remains reserved. Target reset - Resets the entire target. The reset clears any SCSI reservations on all the LUNs associated with that target and makes the LUNs available to all servers again. Get the 3PAR raw disk number to which “LUN / Target reset” operations needs to be done: $ scsimgr lun_map LUN PATH INFORMATION FOR LUN : /dev/rdisk/ disk449 Total number of LUN paths     = 2 World Wide Identifier(WWID)    = 0x60002ac0000000000000011f00000098 LUN path : lunpath59 Class                         = lunpath Instance                      = 59 Hardware path         ...

LUN reset - Resets the specified LUN by clearing any reservation on the LUN and making the LUN available to all servers again. The reset does not affect any of the other LUNs on the device. If another LUN on the device is reserved, it remains reserved. Target reset - Resets the entire target. The reset clears any reservations on all the LUNs associated with that target and makes the LUNs available to all servers again. Make sure if below package is installed on your RHEL host: # rpm -qa | grep sg3 sg3_utils-libs-1.37-12.el7.x86_64 sg3_utils-1.37-12.el7.x86_64 "sg_reset" command comes bundled with "sg3_utils" package, so install it if not installed already.  Get the wwid for the device which needs to be reset: # multipath -ll 360002ac000000000000000820001cb64 dm-23 3PARdata,VV size=2.5T features='1 queue_if_no_path' hwhandler='1 alua' wp=rw `-+- policy='round-robin 0' prio=50 status=active   |- 0:0:0:5  sdj  8:144  ac...

If you are using ESXi 6.5 and seeing below two issues when using VI web-client interface: Java exceptions during VI web-client navigation Not seeing RDM option while adding disk to VM https://communities.vmware.com/thread/542973 These above issues are resolved in the latest available esx-ui package, which can be downloaded from below VMware URL: https://labs.vmware.com/flings/esxi-embedded-host-client#summary Download Offline bundle for ESXi 6.x - esxui-offline-bundle-6.x-5744014.zip Steps: 1. To check currently installed esx-ui package, login to ESXi 6.5 host via SSH and run: # esxcli software vib list | grep esx-ui esx-ui                         1.8.0-4516221                         VMware     VMwareCertified   2017-07-06 2. Copy zip file to any location on the esxi host for example i am copying it to “da...

LUN reset - Resets the specified LUN by clearing any SCSI reservation on the LUN and making the LUN available to all servers again. The reset does not affect any of the other LUNs on the device. If another LUN on the device is reserved, it remains reserved. Target reset - Resets the entire target. The reset clears any SCSI reservations on all the LUNs associated with that target and makes the LUNs available to all servers again. To check all the available devices: # esxcfg-scsidevs -l naa.60002ac000000000000000860001cb64    Device Type: Direct-Access    Size: 2609152 MB    Display Name: 3PARdata Fibre Channel Disk (naa.60002ac000000000000000860001cb64)    Multipath Plugin: NMP    Console Device: /vmfs/devices/disks/naa.60002ac000000000000000860001cb64    Devfs Path: /vmfs/devices/disks/naa.60002ac000000000000000860001cb64    Vendor: 3PARdata  Model: VV        ...