If you need to resize an online multipath device, use the following procedure.
Resize your physical device.
Use the following command to find the paths to the LUN:
# multipath -l
Resize your paths. For SCSI devices, writing a 1 to the rescan file for the device causes the SCSI driver to rescan, as in the following command:
# echo 1 > /sys/block/sda/device/rescan
# echo 1 > /sys/block/sdb/device/rescan
# echo 1 > /sys/block/sdc/device/rescan
Resize your multipath device by running the multipathd resize command:
# multipathd -k’resize map mpath0′
Resize the file system (assuming no LVM or DOS partitions are used):
# xfs_growfs /dev/mapper/mpath0