PVE update storage from VM

[aldTest]

I'm looking for solution why PVE doesn't update usage local storage which I use into vm.

For example in VM I downloaded file (about 10 GB). In PVE -> local storage -> Summary I see information that total Size is increased about 10 GB but when I removed this file from VM. Summary in local storage still show the same Total Size.

 

[fiona]

Hi,
do you have discard enabled on the disk and issued a trim command inside the VM? That's how the guest system can tell the underlying storage that certain parts of the disk are not allocated. See also the TRIM/Discard section here: https://pve.proxmox.com/pve-docs/chapter-qm.html#qm_hard_disk

 

[aldTest]

My configuration looks like image.

 

[fiona]

What kind of storage are you using? Is it thin-provisioned? What if you run fstrim -av inside the guest?

 

[aldTest]

I added disk. which works in raid1 via usb. I used fstrim -av but this solution didn't receive any solution.

 

[fiona]

Please post the output of cat /etc/pve/storage.cfg

 

[aldTest]

dir: local
path /var/lib/vz
content backup,vztmpl,iso

lvmthin: local-lvm
thinpool data
vgname pve
content rootdir,images

dir: M
path /mnt/pve/M
content snippets,iso,vztmpl,backup,images,rootdir
is_mountpoint 1
nodes local

 

[fiona]

That's strange. If it's a dir type storage, the volume should have a suffix, e.g. .raw or .qcow2. Did you change the configuration recently? What is the output of pveversion -v? What was the output of fstrim -av and how much is the actual usage, i.e. qemu-img info /mnt/pve/M/101/vm-101-disk-0?

 

[aldTest]

When I used fstrim -av the sorage shows the correct size. I previously usedfstrim -a but it didn't work. How to use this command in crontab?

 

[fiona]

When I used fstrim -av the sorage shows the correct size. I previously usedfstrim -a but it didn't work. How to use this command in crontab?

Just like you would any other crontab command.

Do you have ext4 and did you move the disk last time when it didn't work? From the docs

There is a caveat with ext4 on Linux, because it uses an in-memory optimization to avoid issuing duplicate TRIM requests. Since the guest doesn’t know about the change in the underlying storage, only the first guest-trim will run as expected. Subsequent ones, until the next reboot, will only considerparts of the filesystem that changed since then.

 

[aldTest]

How can I use disk trim in VM where system is Windows?

 

[fiona]

I think with the guest agent installed, you can use qm agent <ID> fstrim. There are other tools to issue discard from within Windows, just use your favorite search engine.