If you have added a new LUN from SAN, use the following to initiate a rescan of disks (run on all hosts)
echo "- - -" | tee /sys/class/scsi_host/host*/scan
The following should be run on each node
Identify
Use scsi_id to query for the WWID of the new devices (/dev/sdX)
/lib/udev/scsi_id -gud /dev/sdX
Add
Add the WWIDs to the multipath config;
multipath -a <WWID>
(ex; multipath -a 3600144f028f88a0000005037a95d0001)
Activate
Activate the new LUNS
multipath -r
Query
You can query device status for newly added multipath devices
mutlipath -ll
Set up LVM on top of LUNs
Must be done via the CLI. We will create a PV (physical volume) and on top of that, a VG (Volume Group).
replace DEVICE_NAME with the name of the multipath device
pvcreate /dev/mapper/DEVICE_NAME
replace VG_NAME with the desired name for the VG)
vgcreate VG_NAME /dev/mapper/DEVICE_NAME
You can then create an LVM storage for that VG in the Proxmox GUI.
If multiple Proxmox VE cluster nodes can access the LUN, you can inform Proxmox VE about this fact by marking the storage as "shared".
In a Proxmox VE cluster, the new PV and VG may not be immediately visible on all nodes. To make them visible on all nodes, you can either reboot all nodes or run the following command on all nodes:
pvscan --cache
Resize existing LUNS
Rescan should be done on ALL nodes:
pvs -o +tags
lsblk #get all disks /dev id
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
/dev/mapper/360060e80212d6d0050602d6d00000025 (#shared LUN name)
Source:
https://pve.proxmox.com/wiki/Multipath#FC/SAS-specific_configuration