PowerPath

Installation

rpm -ihv /tmp/EMCPower.LINUX-6.2.0.00.00-051.RHEL6.x86_64.rpm
emcpreg -install
powermt check_registration
/etc/init.d/PowerPath start              # RHEL 5-6
systemctl start PowerPath.service        # RHEL 7

PowerPath commands

  • Display High Level HBA I/O Paths: powermt display
  • Display IO stats on each adapter in the specified interval: powermt display every=<x seconds>
  • Display all attached LUNs: powermt display dev=all
  • Display specific LUN: powermt display dev=emcpowera
  • Display available I/O paths: powermt display paths
  • Display EMC PowerPath options: powermt display options
  • Display port status: powermt display port_mode
  • Display PowerPath registration key/status: powermt check_registration
  • Display EMC PowerPath version: powermt version
  • Check the I/O paths, removes dead paths: powermt check
  • Make all dead I/O path alive: powermt restore dev=all
  • Remove all dead paths automatically without any confirmation: powermt check force
  • Remove all I/O path for a particular device: powermt remove dev=emcpowera
  • Remove an I/O path: powermt remove dev=sdd
  • Configure PowerPath: powermt config
  • Save the current Powerpath configuration (/etc/powermt_custom.xml): powermt save
  • Save current PowePath configuration to a specific file: powermt save file=/etc/powermt.15062017
  • Load a specific EMC PowerPath configuration: powermt load file=/etc/powermt.15062017
  • List all pseudo devices: emcpadm getusedpseudos
  • Rename a pseudo device: emcpadm renamepseudo -s emcpowerd -t emcpowera

Remove a LUN

powermt display dev=all
blockdev -–flushbufs /dev/emcpowera
powermt remove dev=emcpowera
powermt release                                          # failing to run this command results in the pseudo device still being visible in /dev and /sys

Resize a LUN

  1. Expand the LUN from the array

  2. For all natives devices associated with the LUN, run the echo 1 > /sys/block/sd*/device/rescan command

echo 1 > /sys/block/sdac/device/rescan
echo 1 > /sys/block/sdt/device/rescan
echo 1 > /sys/block/sdk/device/rescan
echo 1 > /sys/block/sdb/device/rescan
  1. Check the size of the pseudo and native devices
fdisk -cul /dev/{sd{ac,t,k,b},emcpoweri} | grep dev
grep emcpowera /proc/partitions
dmesg
  1. Save PowerPath configuration
powermt config
powermt save
  1. Resize PV and check new size
pvresize /dev/emcpowera
pvdisplay /dev/emcpowera
  1. Extend LV

lvextend -l +100%FREE /dev/u01vg/u01lv

  1. Resize/Extend File system on LV

resize2fs /dev/u01vg/u01lv