How to resize shared FC LUN

Spiros Papageorgiou

Well-Known Member
Aug 1, 2017
Hi all,

I have a proxmox cluster with a shared FC LUN (managed by LVM). The LUN is full and I would like to resize it. I have resized it on the storage but how do i do it in proxmox?

Keep in mind that I'm running multipathd for redudancy and that I have a partition in the LUN. My lsblk looks like is:
sdr 65:16 0 5.9T 0 disk
├─sdr1 65:17 0 2T 0 part
└─mpath0 253:0 0 5.9T 0 mpath
└─mpath0-part1 253:1 0 2T 0 part
├─volgrp1--3par-test 253:4 0 20G 0 lvm
├─volgrp1--3par-vm--103--disk--1 253:5 0 32G 0 lvm
├─volgrp1--3par-vm--100--disk--1 253:6 0 32G 0 lvm

volgrp1--3par is the VG I want to extend.

Last edited:
you must use pvresize to tell lvm an resized physical volumme.
If you have an partition-table on this disk, you have to expand the partition first (but then normaly an reboot is required, because the kernel hold the old (active) partition info in ram) or - create an second partition and add thi to the volume group.

Look with
You normally need to:
- rescan all disks involved in a multipathed device
- rescan the multipath itself, so that your mpath devices shows the new size in multipath -ll
- then continue as @udo said with pveresize
I was looking for how to do the rescan myself and this is how I've done it. I hope this helps someone.

Rescan should be done on ALL nodes:
pvs -o +tags
multipath -ll LUN_name
echo 1 >/sys/block/sdX/device/rescan
echo 1 >/sys/block/sdY/device/rescan
echo 1 >/sys/block/sdZ/device/rescan
echo 1 >/sys/block/sdQ/device/rescan
multipath -r
multipath -ll LUN_name

Then from any node you can resize the PV:
pvresize /dev/mapper/LUN_name
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