Standard pve install. Ubuntu 22.04 LTS. Cannot make snapshot

[gctwnl]

I have set up a very standard PVE install on an internal NVMe disk and am running a single 32GB Ubuntu VM in that environment.

I understand that I cannot create snapshots for that VM because it has 'raw' format (and resides on storage that cannot snapshot itself). I also understand that if I change the format from raw to qcow2 I can snapshot the (running?) VM.

I have two questions:

1. Can a running qcow2 VM with Ubuntu 22.04LTS be snapshotted?
2. How do I change my VM to qcow2 so it can be snapshotted?

Or is there a better way? (third question...)

 

[bbgeek17]

1. Can a running qcow2 VM with Ubuntu 22.04LTS be snapshotted?

yes

1. How do I change my VM to qcow2 so it can be snapshotted?

https://forum.proxmox.com/threads/convert-raw-to-qcow2.76077/

---

Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

 

[gctwnl]

yes

https://forum.proxmox.com/threads/convert-raw-to-qcow2.76077/

---

Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

When I try the suggestion from that thread, the option to change format is greyed out:

 

[bbgeek17]

LVM is a block storage, the data is written in RAW format. However, the snapshots are still supported at LVM level.
If you want QCOW, you need some file storage, ie "local" under normal install.

---

Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

 

[gctwnl]

LVM is a block storage, the data is written in RAW format. However, the snapshots are still supported at LVM level.
If you want QCOW, you need some file storage, ie "local" under normal install.

---

Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

local-lvm is of type LVM-Thin. And LVM-Thin can be snapshotted. I support you mean that by "snapshots are still supported at LVM level"?

If so, how then do I create snapshot for my (raw) VM on LVM-Thin storage? I don't want qcow2 specifically, I'd like to be able to snapshot. Can I do this only via the cli, maybe?

I admit I am somewhat confused.

 

[bbgeek17]

The reason that you and everyone else is confused is because of this statement:

I understand that I cannot create snapshots for that VM because it has 'raw' format (and resides on storage that cannot snapshot itself).

You stated that your VM is in "raw" format on storage that does not support snapshot.
For most people here it would mean that its on the File storage with the format of "Raw" for the file. What you omitted is that the VM is on "local-lvm" which is block storage. It is implied that all data on local-lvm is raw, because the blocks are raw, not wrapped into file system.

Local-lvm supports snapshots. What stops you from selecting the VM>Snapshot and making one? Are you getting an error?

And to avoid any more confusion run these commands and place the output in the the thread in as code.
pvesm status
qm config [vmid in question which you can get from: qm list]

---

Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

 

[gctwnl]

The reason that you and everyone else is confused is because of this statement:


You stated that your VM is in "raw" format on storage that does not support snapshot.
For most people here it would mean that its on the File storage with the format of "Raw" for the file. What you omitted is that the VM is on "local-lvm" which is block storage. It is implied that all data on local-lvm is raw, because the blocks are raw, not wrapped into file system.

Local-lvm supports snapshots. What stops you from selecting the VM>Snapshot and making one? Are you getting an error?

And to avoid any more confusion run these commands and place the output in the the thread in as code.
pvesm status
qm config [vmid in question which you can get from: qm list]

---

Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

I said I cannot create a snapshot (because the GUI did not let me). Under 'Snapshots' for the VM, it says "The current guest configuration does not support taking new snapshots":



So, I tried to figure it out from documentation and searches and I gathered that this was probably the case because the guest was 'raw' and that I probably could if the guest VM was qcow2. Uneducated guesses...

Note, I've done a standard PVE install and that creates a VM in RAW and not on file storage but on LVM-Thin.

root@pve:~# pvesm status
Name                    Type     Status           Total            Used       Available        %
local                    dir     active        98497780         6003176        87445056    6.09%
local-lvm            lvmthin     active       833396736        10500798       822895937    1.26%
rna-internal-pbs         pbs     active       514937088         6648728       482057576    1.29%
rna-mepdm-1              lvm     active      1875234816      1048576000       826658816   55.92%
root@pve:~# qm config 100
boot: order=scsi0;ide2;net0
cores: 2
ide2: local:iso/ubuntu-22.04.1-live-server-amd64.iso,media=cdrom,size=1440306K
memory: 4096
meta: creation-qemu=7.0.0,ctime=1665090989
name: rna-mainserver-vm
net0: virtio=A6:97:9A:EF:7E:EE,bridge=vmbr0,firewall=1
numa: 0
onboot: 1
ostype: l26
scsi0: local-lvm:vm-100-disk-0,size=32G
scsi1: rna-mepdm-1:vm-100-disk-0,backup=0,size=500G
scsihw: virtio-scsi-pci
smbios1: uuid=7b07bbf7-d3d4-4252-85bb-8a4f0b720f82
sockets: 1
vmgenid: d0cb1769-021e-4b1d-ba6f-28a3d5e7eeb1

Note: I am indeed new to all of this (have some technical background in unix-like environments, but Linux and pve are new to me). So I'm definitely more confused than the rest (learning curve and all that). And thanks for trying to help out.

 

[bbgeek17]

scsi1: rna-mepdm-1:vm-100-disk-0,backup=0,size=500G

All disks in VM must be on storage that supports snapshots. This one is not. This is why you are getting that message.

https://pve.proxmox.com/wiki/Live_Snapshots

Requirements
In order to use Proxmox VE live snapshots all your virtual machine disk images must
be stored as qcow2 image or be in a storage that supports live snapshots and is
managed by Proxmox VE. For a list of storage with snapshot capabilities, see Storage

---

Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

 

[gctwnl]

All disks in VM must be on storage that supports snapshots. This one is not. This is why you are getting that message.

https://pve.proxmox.com/wiki/Live_Snapshots

Requirements
In order to use Proxmox VE live snapshots all your virtual machine disk images must
be stored as qcow2 image or be in a storage that supports live snapshots and is
managed by Proxmox VE. For a list of storage with snapshot capabilities, see Storage

---

Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

That is somewhat unexpected. That disk doesn't even need to be mounted on the OS in the VM. In fact, for backups, I can set that disk to be ignored (which I have). The only thing that needs to snapshotted is the VM itself (and its settings)

 

[bbgeek17]

Feel free to add your opinion here: https://bugzilla.proxmox.com/show_bug.cgi?id=1007
Also, pay attention to what happens to your "skipped" disk on backup restore - it will get wiped.

---

Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

 

[gctwnl]

Also, pay attention to what happens to your "skipped" disk on backup restore - it will get wiped.

Arrgh. So, this 'ignore disk' ignores on backup but not on restore? Which means I have to remove the disk from the VM's hardware setup before doing any restore? Or will that restore then not work anymore? No way to backup a VM without its hardware-assigned disks?

 

[gctwnl]

Moved it to a somewhat wider subject here: https://forum.proxmox.com/threads/l...d-pbs-snapshots-suggestions-solicited.117595/