We have CX4-120 EMC SAN storage, I expend existing LUN size to 20GB but now i am not able to see any cylinder changes on host fdisk -l output. Following command i am running to re-scan my hda or LUN

echo "1" > /sys/class/fc_host/host1/issue_lip
echo "1" > /sys/class/fc_host/host2/issue_lip

And then

echo "- - -" > /sys/class/scsi_host/host1/scan
echo "- - -" > /sys/class/scsi_host/host2/scan
echo "- - -" > /sys/class/scsi_host/host3/scan
echo "- - -" > /sys/class/scsi_host/host4/scan
echo "- - -" > /sys/class/scsi_host/host5/scan
echo "- - -" > /sys/class/scsi_host/host6/scan
echo "- - -" > /sys/class/scsi_host/host7/scan

But still fdisk -l /dev/emcpowere showing old cylinder size, Am i missing something? I have qlogic hda

  • It may be an issue with the PowerPath driver. Do you know if the actual block devices pointed to by the emcpowere device are updating? if you do powermt display dev=emcpowere it should tell you which native block devices are different paths to the same emcpowere LUN. – Bratchley Sep 30 '13 at 19:50
  • Also, fwiw, I typically use the rescan-scsi-bus.sh script available in the sg3_utils package on RHEL/CentOS rather than type all that out. Just saves time for you. – Bratchley Sep 30 '13 at 19:52

All above command doesn't work if you expanding existing LUN or re-scaning existing LUN.


echo "1" > /sys/block/<DEVICE>/device/rescan

Handy script:

cd /dev
for DEVICE in `ls sd[a-z] sd?[a-z]`; do echo '1' > /sys/block/$DEVICE/device/rescan; done

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