Cannot see available disk space in LVM

Cannot see available disk space in LVM

I have iSCSI disks connected to my server. i want to resize their
capacity. It has LVM on the disk. when i resize the disk in equallogic
SAN, i gave it 700GB. and when it check its disk space by fdisk -l, it
gives correct size (700GB), but when i run pvscan, it still shows old
size(650GB). i have tried to stop iscsi and start again, as well as
rebooted the server, but still LVM cannot see the disk size increased, but
only fdisk.
Is there any way to referesh the disk size? so LVM Can see it?