Snapshot Not Working. Out of space.

[cdirk07]

I have set up my volume to be thin-provisioned. I am trying to snapshot a VM to run updates but when I do, proxmox says I am out of space.
TASK ERROR: zfs error: cannot create snapshot 'VMStorage/vm-101-disk-2@Test': out of space

Here is the output of zfs list:
NAME USED AVAIL REFER MOUNTPOINT
VMStorage 8.36T 4.15T 24K /VMStorage
VMStorage/vm-101-disk-2 7.62T 7.17T 4.60T -

Do I need to add more disks to up the AVAIL? Looks like the disk2 is using an actual total of 4.6T and my total free storage is at 4.15T? Am I reading this right?

 

[Dunuin]

zfs list -o space will give you some additional information.
You probably didn't checked the "Thin" checkbox when creating that ZFS storage? In that case it wouldn't be thin-provisioned.

 

[cdirk07]

I did not check the box until after reading another article says that I would need the entire reserved space for a snapshot. Here is the output of the command:
NAME AVAIL USED USEDSNAP USEDDS USEDREFRESERV USEDCHILD
VMStorage 4.15T 8.36T 0B 24K 0B 8.36T
VMStorage/vm-101-disk-2 7.17T 7.62T 0B 4.60T 3.01T 0B

Is there anything I can do to force the thin-provision?

 

[Dunuin]

You could use "zfs set" command to remove the refreservation of that zvol. And please put your outputs between CODE-tags in the future. A pain to read those tables otherwise.

So something like: zfs set refreservation=none VMStorage/vm-101-disk-2

 

[cdirk07]

Here is the output of zfs get reservation VMStorage/vm-101-disk-2

NAME                     PROPERTY     VALUE   SOURCE
VMStorage/vm-101-disk-2  reservation  none    default

Is that the setting I should be looking at?

 

[Dunuin]

I really meant "refreservation" and not "reservation".

 

[cdirk07]

I did not change the reservation setting on that volume. It was already like that. Running zfs list -o space shows the same as before

NAME                     AVAIL   USED  USEDSNAP  USEDDS  USEDREFRESERV  USEDCHILD
VMStorage                4.15T  8.36T        0B     24K             0B      8.36T
VMStorage/vm-101-disk-2  7.17T  7.62T        0B   4.60T          3.01T         0B

 

[Dunuin]

I really meant "refreservation" and not "reservation".

 

[cdirk07]

Sorry, I missed that. Looked too much like reservation.

That worked! Thank you.

Since I set the thin-provision after I built all of my VMs, is it best to run that set command on all of the other volumes for the VMs?

 

[Dunuin]

Since I set the thin-provision after I built all of my VMs, is it best to run that set command on all of the other volumes for the VMs?

Yes. Otherwise they stay thick-provisioned.

 

[cdirk07]

Ok. Thanks! I appreciate your help!