[SOLVED] The current guest configuration does not support taking new snapshots

[gannick]

Hello everyone,

My Proxmox have a M2 SSD 500 Go that host Proxmox itself. I added a SATA SSD 2To to store the data that are not supposed to stay in the containers. Like that, easy to backup (in my thinking).

I try to snapshot a container. This container have a share with the host. The share directory is located on a thin-LVM (I recreate my partition because I saw that to snapshot, the filesystem must have that capability here :
https://forum.proxmox.com/threads/t...-does-not-support-taking-new-snapshots.82444/
https://pve.proxmox.com/wiki/Storage

And also I looked that topic : https://forum.proxmox.com/threads/t...not-support-taking-new-snapshots.73944/page-2

So, my data partition is now thin LVM (it is data-lv), according to Internet, the "t" says it is thin-LVM, such as T and V :

# lvs
  LV                             VG   Attr       LSize   Pool Origin        Data%  Meta%  Move Log Cpy%Sync Convert
  data-lv                        data twi-aotz--   1.80t                    0.00   10.42                           
  lvol0                          data -wi------- 116.00m                                                           
  data                           pve  twi-aotz-- 330.51g                    7.91   0.77                           
  root                           pve  -wi-ao----  96.00g                                                           
  snap_vm-100-disk-0_snap_all_ok pve  Vri---tz-k   4.00g data vm-100-disk-0                                       
  snap_vm-102-disk-0_snap_all_ok pve  Vri---tz-k   5.00g data vm-102-disk-0                                       
  snap_vm-106-disk-0_test_snap_1 pve  Vri---tz-k   2.00g data vm-106-disk-0                                       
  swap                           pve  -wi-ao----  16.00g                                                           
  vm-100-disk-0                  pve  Vwi-aotz--   4.00g data               5.37                                   
  vm-101-disk-0                  pve  Vwi-aotz--   8.00g data               40.72                                 
  vm-102-disk-0                  pve  Vwi-aotz--   5.00g data               23.36                                 
  vm-103-disk-0                  pve  Vwi-a-tz--   4.00g data               4.53                                   
  vm-104-disk-0                  pve  Vwi-a-tz--   4.00m data               14.06                                 
  vm-104-disk-1                  pve  Vwi-a-tz--  70.00g data               27.55                                 
  vm-104-disk-2                  pve  Vwi-a-tz--   4.00m data               1.56                                   
  vm-105-disk-0                  pve  Vwi-aotz--   2.00g data               50.90                                 
  vm-106-disk-0                  pve  Vwi-a-tz--   2.00g data               39.69

My storage is well seen by Proxmox, as you can see on that screenshot of my proxmox interface :


Here is the configuration of the container I cannot snapshot :

# cat /etc/pve/lxc/101.conf
arch: amd64
cores: 1
features: nesting=1
hostname: nextcloud
memory: 1024
mp0: /data/data_nextcloud/,mp=/var/data_nextcloud
nameserver: 192.168.1.254
net0: name=eth0,bridge=vmbr0,firewall=1,gw=192.168.1.254,hwaddr=B2:A7:1E:5D:B7:28,ip=192.168.1.237/24,type=veth
onboot: 1
ostype: debian
rootfs: local-lvm:vm-101-disk-0,size=8G
swap: 512
unprivileged: 1
lxc.idmap: u 0 100000 33
lxc.idmap: g 0 100000 33
lxc.idmap: u 33 33 1
lxc.idmap: g 33 33 1
lxc.idmap: u 34 100034 65502
lxc.idmap: g 34 100034 65502

I still cannot take a snapshot of my container. May you have any idea of why ?

At the end, I don't care of a snapshot from the share directory, but I cannot deactivate it. So, what is the problem ? My share data are on a thin LVM partition. This thin partition is seen by Proxmox... Whats wrong ?

 

[spirit]

I'm not sure, but I think it's because of the mountpoint mp0.

 

[gannick]

I'm not sure, but I think it's because of the mountpoint mp0.

Well, I suppose too, but I would like to have an affirmative answer. That's crazy if yes. I am not the only guy who want to have a mountpoint and to snapshot the container ? How do they all do ??

That topic look like you are right : https://forum.proxmox.com/threads/container-w-mount-point-snapshots.36086/

That sounds crazy... Really, I don't understand... With LXD/LXC, it was possible to make snapshot of container with mount point. That is the second issue I have with proxmox that was working very fine with LXD. I appreciate it (container and VM in a same infrastructure, usefull GUI...), but I begin to be plenty of doubt...

 

[gannick]

If I deactivate mount point, I can snapshot... To do that, I must stop the container. Any idea to do that without destroying each time I want to snapshot the mount point ?

 

[gannick]

I created an ext4 partition over the logical volume (such as described here : https://access.redhat.com/documenta...ity_add-on_administration/s1-lvmsetupnfs-haaa. Could it be the problem ?

Does it was a wring thing to do ? If yes, how could I mount a logical volume to a mount point ?

 

[spirit]

I created an ext4 partition over the logical volume (such as described here : https://access.redhat.com/documenta...ity_add-on_administration/s1-lvmsetupnfs-haaa. Could it be the problem ?

Does it was a wring thing to do ? If yes, how could I mount a logical volume to a mount point ?

the problem is that your mountpoint is a directory of the host, so you can't snapshot it.

The only way is to create a dedicated volume for this mountpoint. (the default behaviour when you use the gui to create a mountpoint with a specific size)

 

[gannick]

the problem is that your mountpoint is a directory of the host, so you can't snapshot it.

The only way is to create a dedicated volume for this mountpoint. (the default behaviour when you use the gui to create a mountpoint with a specific size)

Thanks for your answer. So, I must have my 2Tb disk set as LVM volum group, and then, in the Proxmox GUI, I create a dedicated volume as logical volume ? Am I right ?

 

[gannick]

@spirit : you were right. I destroyed everything I have had created on my 2Tb disk dedicated to the data.

Then :
1) With fdisk I created a partition on the full disk
2) In the Proxmox GUI, in the Thin LVM part of my server, I created a volume group on all the disk
3) In the Container where I would like to share data, I created the mount point and create a logical volume hosted in the volume group I just created
4) I am able to mount as EXT4 the logical volume in the host and in the container

My new experience on Proxmoc teach me to administrate disks from the GUI Proxmox and not from the CLI to have things working well. I will tag this subject as solved.