Warning message againt thinpool when starting Snapshot

[llinty]

Hello,

I have configured LVM thin provisionning on Proxmox as following

LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
data pve twi-aotz-- 140.39g 48.70 3.43
root pve -wi-ao---- 55.75g
swap pve -wi-ao---- 8.00g
vm-100-disk-0 pve Vwi-aotz-- 20.00g data 94.68
vm-100-state-Test pve Vwi-a-tz-- <40.49g data 17.28
vm-101-disk-0 pve Vwi-aotz-- 32.00g data 11.29
vm-102-disk-0 pve Vwi-aotz-- 8.00g data 81.27
vm-103-disk-0 pve Vwi-aotz-- 32.00g data 93.67
vm-105-disk-0 pve Vwi-a-tz-- 32.00g data 7.34
thinpool vm-data twi-aotz-- 8.00t 27.72 30.70
vm-100-disk-0 vm-data Vwi-aotz-- 4.00t thinpool 48.96
vm-104-disk-0 vm-data Vwi-aotz-- 127.00g thinpool 66.33
vm-104-disk-1 vm-data Vwi-aotz-- 4.00m thinpool 18.75
vm-104-disk-2 vm-data Vwi-aotz-- 200.00g thinpool 90.61

When I'm starting Snapshot of the biggest VM (VMD: 100) I have this message:

WARNING: You have not turned on protection against thin pools running out of space.
WARNING: Set activation/thin_pool_autoextend_threshold below 100 to trigger automatic extension of thin pools before they get full.
Logical volume "vm-100-state-Test" created.
WARNING: Sum of all thin volume sizes (<164.49 GiB) exceeds the size of thin pool pve/data and the amount of free space in volume group (<16.00 GiB).

I have stopped the Snapshot vm-100-state-Test during its creation. It was stopped in the preparing state. I have to remove it from the VM 100 conf file to unlock the VM and restart the VM after.

Please advise on autoextend message.
Laurent

 

[fabian]

the message just tells you that the total size of the volumes in the thin pool is bigger than the pool (you've overcommitted storage). if all guests were to start filling their disks, you'd run out of space (with potential corruption/data loss as a result). this is a risk with all thin-provisioned storages that allow you to allocate more space than actually exists - you need to monitor usage and are responsible for staying under the actual space that is available.

 

[llinty]

the message just tells you that the total size of the volumes in the thin pool is bigger than the pool (you've overcommitted storage). if all guests were to start filling their disks, you'd run out of space (with potential corruption/data loss as a result). this is a risk with all thin-provisioned storages that allow you to allocate more space than actually exists - you need to monitor usage and are responsible for staying under the actual space that is available.

Thank you for your answer @fabian !
My problem is that I have physically 8 TB of disk storage. The thinpool vm-data as been created as well. My Biggest VM (VMID 100) is owning a thin volume of 4 TB. This VM has currently allocated 800GB of data which is very low regardless the size of the thin volume and the existing physical size. What did I do wrong in my configuration? Why is it considered as overcommitted storage?
Many thanks for your help.

 

[fabian]

this is about the default thin pool "data" with size 140.39G, not the big one you created in addition that is 8T in size... the VM has a disk there as well, and it seems it is used as storage for the 'state' volume as well..

 

[llinty]

this is about the default thin pool "data" with size 140.39G, not the big one you created in addition that is 8T in size... the VM has a disk there as well, and it seems it is used as storage for the 'state' volume as well..

Yes for sure after having double checked the message the problem is on this thin pool. Is there a way to change the default thin pool to the one with more space?

 

[fabian]

you can move the disk(s)/volume(s) (and also change the state storage used for dumping the memory and other VM state in a snapshot with RAM included).