How can i copy a virtual disk from a thin pool

contoso

New Member
Jan 8, 2025
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Hi, im new to proxmox and not very familiar with linux at all. But i try my best. So may i ask something that is very clear for you but not for me.

// What i have:
A new ProLiant Server with hardware raid and everything redundant. Proxmox is running, network is an lag with vlans, everything ok.

// What i did:

First i delete my testing raid disk
Code:
wipefs --all --backup /dev/sda

Create a partition on that disk
Code:
sgdisk -N 1 /dev/sda

Creat a LVM GPT disk
Code:
pvcreate --metadatasize 1024M /dev/sda1

Create a volume group with that disk
Code:
vgcreate --metadatasize 1024M vgroup1 /dev/sda1

Create a thin pool with that volume group with all the space of it (except 5% left free, sure is sure)
Code:
lvcreate -l 95%FREE --poolmetadatasize 2048M --chunksize 256 -T -n tpool1 vgroup1

In GUI at Datacenter > Storage
Create a LVM-Thin entry with id vmdata and volumegroup, thin pool information from above and content disk image and container.

Now my proxmox server can use that thinpool and everything is working.

// My problem:
In the system shell, when i do
Code:
ls -lah /dev/mapper
there i can see all the volumes of my virtual servers.
As far as i understand, a thinpool creates (i dont know another word for it) a "fake-disk" where all my thin-volumes are saved.

But i dont know how i can "mount" that thinpool so that i can just copy a disk of a virtual machine. Copy for example to another disk or wherever.
Aren't that disks inside the thinpool saved anywhere as a file anywhere?

The ls -lah shows me a pointer to "anything" thats call like "../dm-10, ../dm-11, ..dm-12... and so on. But i cant see (and i dont know how) where this pointer go to. i just see "../dm-10" for example. I cant see the full path.

Yes, may be i missunderstood something here. But i hope anyone of you is smarter than i am :-)

Thanks a lot!
 
Last edited:
I assume you did a pve with lvm installation ? So see "vgs ; lvs" where you have default a vg "pve" and a lvm(thick) "root" and a LVM-thin "data".
Coming to your vg "vgroup1" where you have to define a lvm-thick or lvm-thin volume for your file space needs, after mkfs.<???> on that and mount it anywhere.
 
https://search.brave.com/search?q=p...summary=1&conversation=9867daa3a92efc35cacd1a

Depends. Is the disk that you want to clone from lvm-thin bootable, or just data?

If just data, you can copy files off it with scp or the like to the host, or to another running VM's disk.

If it's bootable, you should probably clone the VM
The disks were just data. Not bootable. Its not about cloning a machine, i can do that inside the gui or with Veeam. Its just about if it's possible to copy the "virtual disk file" from the virtual machines.

For example, adding a USB 3TB Disk and then copy the disks of virtual machines.
 
It's not really possible to clone a vdisk on lvm-thin backing storage the way you would with a conventional .vmdk or .vdi file.

You can move it onto e.g. XFS, or do a backup from the GUI to regular storage / PBS and restore it as a different VM number