This tutorial shows how to set up an extra harddisk in Promox, and split it in storage and a thinlvm pool.

Format the disk, create a physical volume and volume group

Find the new drive with fdisk:

fdisk -l

Create a partition on the new drive:

fdisk /dev/sdb

Validate the partition is there:

fdisk -l

Create a physical volume on the new partition:

pvcreate /dev/sdb1

Create a new volume group:

vgcreate hdd2 /dev/sdb1

Check if the volume group has been created:

vgdisplay

Create a storage directory (backups, ISO images)

Create a new logical volume for the backup in the new group:

lvcreate -n hdd2_data -L 300G hdd2 

Create a file system on the data lv:

mkfs.ext4 /dev/mapper/hdd2_data

Mount the data directory:

mount /dev/mapper/hdd2_data /mnt/hdd2_data

To automount the drive, find the UUID:

blkid /dev/mapper/hdd2_data

Append the following in /etc/fstab:

UUID=<UUID> /mnt/hdd2_data ext4 defaults 0 2

You can now add the drive via the UI: Data Center->Storage->Add->Directory.

As the directory fill in the mount point.

Create a lvm-thin pool (running VM’s)

Create a new logical volume, for example with the remaining disk space

lvcreate -l100%FREE -n hdd2_thin-lvm hdd2

*sometimes 100% does not work, in that case 99% probably will.

Convert the logical volume into a thin-lvm:

lvconvert --type thin-pool hdd2_lvmthin

You can add more metadata storage if required, the default might be only a few megabytes:

lvextend --poolmetadatasize +1G hdd2_lvmthin

You can now add the drive via the UI: Data Center->Storage->Add->LVM-Thin.

More reading

• How to Add New Disks Using LVM to an Existing Linux System
• LFCS: How to Manage and Create LVM Using vgcreate, lvcreate and lvextend Commands
• Adding disk as LVM to proxmox